You will need an Ubuntu server with root access or an account with sudo privileges.

The following are the steps to install Ejabberd:

Ejabberd binaries are available as a Debian package. It includes a minimum Erlang runtime and all other dependencies. You can download the latest package from the Ejabberd download page.

The installer unpacks all the contents at the /opt/ejabberd-version directory. You can get an exact location of the installation with the whereis command. All executable files are generally located under the bin directory. We will mostly be working with ejabberdctl, which is a command line administrative tool. It provides various options to manage and monitor Ejabberd installation. You can see the full list of supported options by entering ejabberdctl without any options.

The following screenshot shows the partial output of executing ejabberdctl without any options:

If you have noticed, I am using sudo with each ejabberdctl command. You can avoid the use of the sudo command by switching to the ejabberd user, which is created at the time of Ejabberd installation. The installer creates a system user account, ejabberd, and sets its home directory to the Ejabberd installation directory, /opt/ejabberd-version. You will still need to use sudo to switch user accounts as the ejabberd user has no password set. Use the following command to log in as the ejabberd user:

$ sudo su ejabberd

In addition to creating the system user to run the Ejabberd process, the installer also creates an ejabberd admin account. The username and password for the administrator account is set to admin/admin. Make sure that you change this password before using your server in production. The installation process also creates a default XMPP host. The hostname is set to match your server hostname. It can be modified from the configuration file.

Once the server has started, you can access the handy web administrative console to manage most of the Ejabberd settings. You can add new users, create access control lists and set access rules, check the participating servers (node), and all hosted XMPP domains (host). Additionally, you can enable or disable Ejabberd modules separately for each domain. That means if you are using the same server to host xmpp1.example1.com and xmpp2.example2.com, you can enable a multi-user chat for xmpp1.example1.com and disable the same module for xmpp2.example2.com.

You will need an Ubuntu server with root access or an account with sudo privileges.

The following are the steps to install Ejabberd:

Ejabberd binaries are available as a Debian package. It includes a minimum Erlang runtime and all other dependencies. You can download the latest package from the Ejabberd download page.

The installer unpacks all the contents at the /opt/ejabberd-version directory. You can get an exact location of the installation with the whereis command. All executable files are generally located under the bin directory. We will mostly be working with ejabberdctl, which is a command line administrative tool. It provides various options to manage and monitor Ejabberd installation. You can see the full list of supported options by entering ejabberdctl without any options.

The following screenshot shows the partial output of executing ejabberdctl without any options:

If you have noticed, I am using sudo with each ejabberdctl command. You can avoid the use of the sudo command by switching to the ejabberd user, which is created at the time of Ejabberd installation. The installer creates a system user account, ejabberd, and sets its home directory to the Ejabberd installation directory, /opt/ejabberd-version. You will still need to use sudo to switch user accounts as the ejabberd user has no password set. Use the following command to log in as the ejabberd user:

$ sudo su ejabberd

In addition to creating the system user to run the Ejabberd process, the installer also creates an ejabberd admin account. The username and password for the administrator account is set to admin/admin. Make sure that you change this password before using your server in production. The installation process also creates a default XMPP host. The hostname is set to match your server hostname. It can be modified from the configuration file.

Once the server has started, you can access the handy web administrative console to manage most of the Ejabberd settings. You can add new users, create access control lists and set access rules, check the participating servers (node), and all hosted XMPP domains (host). Additionally, you can enable or disable Ejabberd modules separately for each domain. That means if you are using the same server to host xmpp1.example1.com and xmpp2.example2.com, you can enable a multi-user chat for xmpp1.example1.com and disable the same module for xmpp2.example2.com.

The following are the steps to install Ejabberd:

Ejabberd binaries are available as a Debian package. It includes a minimum Erlang runtime and all other dependencies. You can download the latest package from the Ejabberd download page.

The installer unpacks all the contents at the /opt/ejabberd-version directory. You can get an exact location of the installation with the whereis command. All executable files are generally located under the bin directory. We will mostly be working with ejabberdctl, which is a command line administrative tool. It provides various options to manage and monitor Ejabberd installation. You can see the full list of supported options by entering ejabberdctl without any options.

The following screenshot shows the partial output of executing ejabberdctl without any options:

If you have noticed, I am using sudo with each ejabberdctl command. You can avoid the use of the sudo command by switching to the ejabberd user, which is created at the time of Ejabberd installation. The installer creates a system user account, ejabberd, and sets its home directory to the Ejabberd installation directory, /opt/ejabberd-version. You will still need to use sudo to switch user accounts as the ejabberd user has no password set. Use the following command to log in as the ejabberd user:

$ sudo su ejabberd

In addition to creating the system user to run the Ejabberd process, the installer also creates an ejabberd admin account. The username and password for the administrator account is set to admin/admin. Make sure that you change this password before using your server in production. The installation process also creates a default XMPP host. The hostname is set to match your server hostname. It can be modified from the configuration file.

Once the server has started, you can access the handy web administrative console to manage most of the Ejabberd settings. You can add new users, create access control lists and set access rules, check the participating servers (node), and all hosted XMPP domains (host). Additionally, you can enable or disable Ejabberd modules separately for each domain. That means if you are using the same server to host xmpp1.example1.com and xmpp2.example2.com, you can enable a multi-user chat for xmpp1.example1.com and disable the same module for xmpp2.example2.com.

Ejabberd binaries are available as a Debian package. It includes a minimum Erlang runtime and all other dependencies. You can download the latest package from the Ejabberd download page.

The installer unpacks all the contents at the /opt/ejabberd-version directory. You can get an exact location of the installation with the whereis command. All executable files are generally located under the bin directory. We will mostly be working with ejabberdctl, which is a command line administrative tool. It provides various options to manage and monitor Ejabberd installation. You can see the full list of supported options by entering ejabberdctl without any options.

The following screenshot shows the partial output of executing ejabberdctl without any options:

If you have noticed, I am using sudo with each ejabberdctl command. You can avoid the use of the sudo command by switching to the ejabberd user, which is created at the time of Ejabberd installation. The installer creates a system user account, ejabberd, and sets its home directory to the Ejabberd installation directory, /opt/ejabberd-version. You will still need to use sudo to switch user accounts as the ejabberd user has no password set. Use the following command to log in as the ejabberd user:

$ sudo su ejabberd

In addition to creating the system user to run the Ejabberd process, the installer also creates an ejabberd admin account. The username and password for the administrator account is set to admin/admin. Make sure that you change this password before using your server in production. The installation process also creates a default XMPP host. The hostname is set to match your server hostname. It can be modified from the configuration file.

Once the server has started, you can access the handy web administrative console to manage most of the Ejabberd settings. You can add new users, create access control lists and set access rules, check the participating servers (node), and all hosted XMPP domains (host). Additionally, you can enable or disable Ejabberd modules separately for each domain. That means if you are using the same server to host xmpp1.example1.com and xmpp2.example2.com, you can enable a multi-user chat for xmpp1.example1.com and disable the same module for xmpp2.example2.com.

Make sure that you have installed the Ejabberd server and it is running properly.

Additionally, you will need XMPP client software. You can choose from multiple free and open source clients such as pidgin, PSI, Adium, Gajim, and many more. I will be using PSI as it provides various low-level administrative features.

Ejabberd supports multiple methods for registering a new user account. These include adding a new user from the command line, creating a new user from the admin panel, and allowing clients to register with the server using in-band registration. Here, we will create a new user from a command line admin tool. Later in this recipe, I will briefly explain another two methods.

Follow these steps to create a user account and connect it with a XMPP client:

The preceding example demonstrates the account creation and client setup process for connecting with the XMPP server. We have used an administrative command to create an XMPP account and then configured client software to use the existing account.

You can also create a new account from the Ejabberd web console. The web console lists all the configured hostnames under the Virtual Hosts section, and each host lists options for user and access management, and other administration tools. Both these options need the server administrator to create an account.

Additionally, XMPP supports an extension that enables a user to self-register with the server. This is called in-band registration (xep-0077), where a user can send his registration request with his desired username, password, and other details, such as email, and the server creates a new user account. This is useful with public XMPP servers where administrators cannot handle all registration requests. The Ejabberd server supports in-band registration with the mod_register plugin, which is enabled by default. From the client side, you can use any XMPP client that supports in-band registration. If you have noticed, PSI also supports in-band registration and provides an option to register a new account in the Add Account process:

When it is an XMPP administration task, PSI is a handy tool. It provides a debug console where you can monitor all XML data transfers between the client and server, as well as send arbitrary XML stanzas to the server. You can access the XML console from right-clicking the menu of your PSI account. Once opened, check Enable checkbox to enable traffic monitoring. The XML Console looks similar to the following screenshot:

XML Console also allows the filtering of traffic based on packet type. Button Dump Ringbuf can be used to dump any traffic before opening the XML Console.

Another option is service discovery from the right-click menu. You need to log in as an administrator to see all the options under service discovery. From here, you can monitor user accounts and various services that are available on the server. The Service Discovery window looks something like this:

Make sure that you have installed the Ejabberd server and it is running properly.

Additionally, you will need XMPP client software. You can choose from multiple free and open source clients such as pidgin, PSI, Adium, Gajim, and many more. I will be using PSI as it provides various low-level administrative features.

Ejabberd supports multiple methods for registering a new user account. These include adding a new user from the command line, creating a new user from the admin panel, and allowing clients to register with the server using in-band registration. Here, we will create a new user from a command line admin tool. Later in this recipe, I will briefly explain another two methods.

Follow these steps to create a user account and connect it with a XMPP client:

The preceding example demonstrates the account creation and client setup process for connecting with the XMPP server. We have used an administrative command to create an XMPP account and then configured client software to use the existing account.

You can also create a new account from the Ejabberd web console. The web console lists all the configured hostnames under the Virtual Hosts section, and each host lists options for user and access management, and other administration tools. Both these options need the server administrator to create an account.

Additionally, XMPP supports an extension that enables a user to self-register with the server. This is called in-band registration (xep-0077), where a user can send his registration request with his desired username, password, and other details, such as email, and the server creates a new user account. This is useful with public XMPP servers where administrators cannot handle all registration requests. The Ejabberd server supports in-band registration with the mod_register plugin, which is enabled by default. From the client side, you can use any XMPP client that supports in-band registration. If you have noticed, PSI also supports in-band registration and provides an option to register a new account in the Add Account process:

When it is an XMPP administration task, PSI is a handy tool. It provides a debug console where you can monitor all XML data transfers between the client and server, as well as send arbitrary XML stanzas to the server. You can access the XML console from right-clicking the menu of your PSI account. Once opened, check Enable checkbox to enable traffic monitoring. The XML Console looks similar to the following screenshot:

XML Console also allows the filtering of traffic based on packet type. Button Dump Ringbuf can be used to dump any traffic before opening the XML Console.

Another option is service discovery from the right-click menu. You need to log in as an administrator to see all the options under service discovery. From here, you can monitor user accounts and various services that are available on the server. The Service Discovery window looks something like this:

Ejabberd supports multiple methods for registering a new user account. These include adding a new user from the command line, creating a new user from the admin panel, and allowing clients to register with the server using in-band registration. Here, we will create a new user from a command line admin tool. Later in this recipe, I will briefly explain another two methods.

Follow these steps to create a user account and connect it with a XMPP client:

The preceding example demonstrates the account creation and client setup process for connecting with the XMPP server. We have used an administrative command to create an XMPP account and then configured client software to use the existing account.

You can also create a new account from the Ejabberd web console. The web console lists all the configured hostnames under the Virtual Hosts section, and each host lists options for user and access management, and other administration tools. Both these options need the server administrator to create an account.

Additionally, XMPP supports an extension that enables a user to self-register with the server. This is called in-band registration (xep-0077), where a user can send his registration request with his desired username, password, and other details, such as email, and the server creates a new user account. This is useful with public XMPP servers where administrators cannot handle all registration requests. The Ejabberd server supports in-band registration with the mod_register plugin, which is enabled by default. From the client side, you can use any XMPP client that supports in-band registration. If you have noticed, PSI also supports in-band registration and provides an option to register a new account in the Add Account process:

When it is an XMPP administration task, PSI is a handy tool. It provides a debug console where you can monitor all XML data transfers between the client and server, as well as send arbitrary XML stanzas to the server. You can access the XML console from right-clicking the menu of your PSI account. Once opened, check Enable checkbox to enable traffic monitoring. The XML Console looks similar to the following screenshot:

XML Console also allows the filtering of traffic based on packet type. Button Dump Ringbuf can be used to dump any traffic before opening the XML Console.

Another option is service discovery from the right-click menu. You need to log in as an administrator to see all the options under service discovery. From here, you can monitor user accounts and various services that are available on the server. The Service Discovery window looks something like this:

The preceding example demonstrates the account creation and client setup process for connecting with the XMPP server. We have used an administrative command to create an XMPP account and then configured client software to use the existing account.

You can also create a new account from the Ejabberd web console. The web console lists all the configured hostnames under the Virtual Hosts section, and each host lists options for user and access management, and other administration tools. Both these options need the server administrator to create an account.

Additionally, XMPP supports an extension that enables a user to self-register with the server. This is called in-band registration (xep-0077), where a user can send his registration request with his desired username, password, and other details, such as email, and the server creates a new user account. This is useful with public XMPP servers where administrators cannot handle all registration requests. The Ejabberd server supports in-band registration with the mod_register plugin, which is enabled by default. From the client side, you can use any XMPP client that supports in-band registration. If you have noticed, PSI also supports in-band registration and provides an option to register a new account in the Add Account process:

When it is an XMPP administration task, PSI is a handy tool. It provides a debug console where you can monitor all XML data transfers between the client and server, as well as send arbitrary XML stanzas to the server. You can access the XML console from right-clicking the menu of your PSI account. Once opened, check Enable checkbox to enable traffic monitoring. The XML Console looks similar to the following screenshot:

XML Console also allows the filtering of traffic based on packet type. Button Dump Ringbuf can be used to dump any traffic before opening the XML Console.

Another option is service discovery from the right-click menu. You need to log in as an administrator to see all the options under service discovery. From here, you can monitor user accounts and various services that are available on the server. The Service Discovery window looks something like this:

When it is an XMPP administration task, PSI is a handy tool. It provides a debug console where you can monitor all XML data transfers between the client and server, as well as send arbitrary XML stanzas to the server. You can access the XML console from right-clicking the menu of your PSI account. Once opened, check Enable checkbox to enable traffic monitoring. The XML Console looks similar to the following screenshot:

XML Console also allows the filtering of traffic based on packet type. Button Dump Ringbuf can be used to dump any traffic before opening the XML Console.

Another option is service discovery from the right-click menu. You need to log in as an administrator to see all the options under service discovery. From here, you can monitor user accounts and various services that are available on the server. The Service Discovery window looks something like this:

Make sure that you have installed the Ejabberd server.

You will need access to a root account or an account with sudo privileges.

Ejabberd configuration files are located under the conf directory in the Ejabberd installation. On the Ubuntu server, it should be /opt/ejabberd-version/conf.

Follow these steps to configure the Ejabberd installation:

Most of the core settings of Ejabberd are controlled through the configuration file, ejabberd.yml. Alternatively, you can change settings with the ejabberdctl command, but those settings will not persist after restart. If you need the settings to be permanent, change them in the configuration file. You can always reload the configuration file changes without restarting the server.

While editing the configuration file, make sure that you follow the indentation and spacing as shown in examples. Ejabberd configuration follows the YML format and any change in spacing will leave that setting undefined. The good news is that the latest version of Ejabberd will prompt you about any mistakes in configuration.

There's another file named ejabberdctl.cfg that contains Erlang runtime settings. You may need to update those parameters while performance tuning the Ejabberd server.

The Ejabberd server is highly extensible and customizable thanks to its modular architecture. Most Ejabberd features are implemented as external modules. Modules are pluggable components that can be used to extend core functionality. These modules can be enabled or disabled as per requirements and do not affect the core functionality. Ejabberd modules are written in either Erlang or Elixir.

Ejabberd modules work with the hook mechanism implemented in the Ejabberd core. Hooks are nothing but simple events such as message received, user logged in, and connection time out. You can get a full list of supported hooks in the Ejabberd documentation, although it may not be a complete list. Each hook gets its own handler chain, with each handler assigned with a priority number. When you enable a module, it registers a given handler with a respective hook and a position or priority in the handler chain. When a hook is triggered by an event, it executes each handler in a chain, one after another. Additionally, a handler function may request to stop processing hooks and not to execute any further handlers.

The Ejabberd administrative command ejabberdctl provides an option to search for and install external modules. Ejabberd takes care of downloading the module, compiling, and installing it. You can even write your own module and add it to the local repository for installation. Check Ejabberd's developer documents for more details on module development.

Make sure that you have installed the Ejabberd server.

You will need access to a root account or an account with sudo privileges.

Ejabberd configuration files are located under the conf directory in the Ejabberd installation. On the Ubuntu server, it should be /opt/ejabberd-version/conf.

Follow these steps to configure the Ejabberd installation:

Most of the core settings of Ejabberd are controlled through the configuration file, ejabberd.yml. Alternatively, you can change settings with the ejabberdctl command, but those settings will not persist after restart. If you need the settings to be permanent, change them in the configuration file. You can always reload the configuration file changes without restarting the server.

While editing the configuration file, make sure that you follow the indentation and spacing as shown in examples. Ejabberd configuration follows the YML format and any change in spacing will leave that setting undefined. The good news is that the latest version of Ejabberd will prompt you about any mistakes in configuration.

There's another file named ejabberdctl.cfg that contains Erlang runtime settings. You may need to update those parameters while performance tuning the Ejabberd server.

The Ejabberd server is highly extensible and customizable thanks to its modular architecture. Most Ejabberd features are implemented as external modules. Modules are pluggable components that can be used to extend core functionality. These modules can be enabled or disabled as per requirements and do not affect the core functionality. Ejabberd modules are written in either Erlang or Elixir.

Ejabberd modules work with the hook mechanism implemented in the Ejabberd core. Hooks are nothing but simple events such as message received, user logged in, and connection time out. You can get a full list of supported hooks in the Ejabberd documentation, although it may not be a complete list. Each hook gets its own handler chain, with each handler assigned with a priority number. When you enable a module, it registers a given handler with a respective hook and a position or priority in the handler chain. When a hook is triggered by an event, it executes each handler in a chain, one after another. Additionally, a handler function may request to stop processing hooks and not to execute any further handlers.

The Ejabberd administrative command ejabberdctl provides an option to search for and install external modules. Ejabberd takes care of downloading the module, compiling, and installing it. You can even write your own module and add it to the local repository for installation. Check Ejabberd's developer documents for more details on module development.

Ejabberd configuration files are located under the conf directory in the Ejabberd installation. On the Ubuntu server, it should be /opt/ejabberd-version/conf.

Follow these steps to configure the Ejabberd installation:

Most of the core settings of Ejabberd are controlled through the configuration file, ejabberd.yml. Alternatively, you can change settings with the ejabberdctl command, but those settings will not persist after restart. If you need the settings to be permanent, change them in the configuration file. You can always reload the configuration file changes without restarting the server.

While editing the configuration file, make sure that you follow the indentation and spacing as shown in examples. Ejabberd configuration follows the YML format and any change in spacing will leave that setting undefined. The good news is that the latest version of Ejabberd will prompt you about any mistakes in configuration.

There's another file named ejabberdctl.cfg that contains Erlang runtime settings. You may need to update those parameters while performance tuning the Ejabberd server.

The Ejabberd server is highly extensible and customizable thanks to its modular architecture. Most Ejabberd features are implemented as external modules. Modules are pluggable components that can be used to extend core functionality. These modules can be enabled or disabled as per requirements and do not affect the core functionality. Ejabberd modules are written in either Erlang or Elixir.

Ejabberd modules work with the hook mechanism implemented in the Ejabberd core. Hooks are nothing but simple events such as message received, user logged in, and connection time out. You can get a full list of supported hooks in the Ejabberd documentation, although it may not be a complete list. Each hook gets its own handler chain, with each handler assigned with a priority number. When you enable a module, it registers a given handler with a respective hook and a position or priority in the handler chain. When a hook is triggered by an event, it executes each handler in a chain, one after another. Additionally, a handler function may request to stop processing hooks and not to execute any further handlers.

The Ejabberd administrative command ejabberdctl provides an option to search for and install external modules. Ejabberd takes care of downloading the module, compiling, and installing it. You can even write your own module and add it to the local repository for installation. Check Ejabberd's developer documents for more details on module development.

Most of the core settings of Ejabberd are controlled through the configuration file, ejabberd.yml. Alternatively, you can change settings with the ejabberdctl command, but those settings will not persist after restart. If you need the settings to be permanent, change them in the configuration file. You can always reload the configuration file changes without restarting the server.

While editing the configuration file, make sure that you follow the indentation and spacing as shown in examples. Ejabberd configuration follows the YML format and any change in spacing will leave that setting undefined. The good news is that the latest version of Ejabberd will prompt you about any mistakes in configuration.

There's another file named ejabberdctl.cfg that contains Erlang runtime settings. You may need to update those parameters while performance tuning the Ejabberd server.

The Ejabberd server is highly extensible and customizable thanks to its modular architecture. Most Ejabberd features are implemented as external modules. Modules are pluggable components that can be used to extend core functionality. These modules can be enabled or disabled as per requirements and do not affect the core functionality. Ejabberd modules are written in either Erlang or Elixir.

Ejabberd modules work with the hook mechanism implemented in the Ejabberd core. Hooks are nothing but simple events such as message received, user logged in, and connection time out. You can get a full list of supported hooks in the Ejabberd documentation, although it may not be a complete list. Each hook gets its own handler chain, with each handler assigned with a priority number. When you enable a module, it registers a given handler with a respective hook and a position or priority in the handler chain. When a hook is triggered by an event, it executes each handler in a chain, one after another. Additionally, a handler function may request to stop processing hooks and not to execute any further handlers.

The Ejabberd administrative command ejabberdctl provides an option to search for and install external modules. Ejabberd takes care of downloading the module, compiling, and installing it. You can even write your own module and add it to the local repository for installation. Check Ejabberd's developer documents for more details on module development.

The Ejabberd server is highly extensible and customizable thanks to its modular architecture. Most Ejabberd features are implemented as external modules. Modules are pluggable components that can be used to extend core functionality. These modules can be enabled or disabled as per requirements and do not affect the core functionality. Ejabberd modules are written in either Erlang or Elixir.

Ejabberd modules work with the hook mechanism implemented in the Ejabberd core. Hooks are nothing but simple events such as message received, user logged in, and connection time out. You can get a full list of supported hooks in the Ejabberd documentation, although it may not be a complete list. Each hook gets its own handler chain, with each handler assigned with a priority number. When you enable a module, it registers a given handler with a respective hook and a position or priority in the handler chain. When a hook is triggered by an event, it executes each handler in a chain, one after another. Additionally, a handler function may request to stop processing hooks and not to execute any further handlers.

The Ejabberd administrative command ejabberdctl provides an option to search for and install external modules. Ejabberd takes care of downloading the module, compiling, and installing it. You can even write your own module and add it to the local repository for installation. Check Ejabberd's developer documents for more details on module development.

You will need the XMPP server installed and running. You can also use public XMPP servers, but make sure that you register with them and obtain your username (JID) and password.

You will need at least two user accounts to communicate with each other.

As we are using a web-based connection, it needs a Bidirectional-streams Over Synchronous HTTP (BOSH) extension enabled on the XMPP server. Ejabberd supports this functionality with mod_http_bind and it should be enabled by default.

Download and extract the latest source achieve from the Strophe.js site: http://strophe.im/strophejs/.

Optionally, you will need a web server set up to access a web client.

I assume the source code is located in the StropheJS directory. We will use one of the examples shipped with the StropheJS source:

Strophe.js is a JavaScript-based XMPP client library that makes it easy to write your own web-based XMPP clients. Strophe handles all actual communication parts, such as the encoding and decoding of XML stanzas, the connection procedure, and so on. You can use simple APIs provided by Strophe to create your client. Strophe.js uses jQuery to work with the HTML DOM, so if you are familiar with jQuery you will feel at home when working with Strophe.

If you browse through the code in echobot.js, you will see two main event handlers: onConnect and onMessage. These event handlers are attached to specific events and are executed when that event occurs. The onConnect handler is attached to a connection object to capture any change in connection state, and onMessage is attached as a handler for message events. It will be triggered when our client receives any message from the server.

If you are interested in the syntax for the addHandler function, it is as follows:

addHandler: function (handler,ns,name,type,id,from,options)

The handler parameter is the actual function to manipulate an incoming message object; ns is the XMPP namespace and can be used to receive packets only from a certain namespace. It defaults to jabber:client, the name parameter, which is the name of an element to act upon—in our case, it is message. You can use iq or presence to receive respective data types. Other parameters add more filtering options, where you can specify a specific ID for the message, type of the message packet (chat or normal or group, defaults to chat) and other options.

The handler function onMessage gets triggered whenever a connection object receives a new message from the server. Then, it parses the received data and extracts all required information. As it is an echo bot, it simply reads the message and echoes it back to the sender. The new message packet is generated with the following lines:

var reply = $msg({to: from, from: to, type: 'chat'})
    .cnode(Strophe.copyElement(body));

The message is passed to a connection object with the following lines, which in turn sends it to the server:

connection.send(reply.tree());

The last section initiates the Strophe client on page load (ready). When we click on the connect button, a click handler in this section gets triggered and opens a new connection with the XMPP server. The same button is changed to disconnect so that we can send a proper disconnect request to the server.

Strophe.js supports WebSocket-based XMPP connections, and the latest version of Ejabberd has also added support for WebSockets. WebSockets provides noticeable performance improvements and reduces connection time over BOSH connections. In the preceding example, we have used the BOSH protocol, which can be replaced with WebSocket simply by changing the BOSH_SERVICE URL as follows:

var BOSH_SERVICE = 'ws:// hostname:5280/websocket';

If you need a secure WebSocket connection, use the wss protocol instead of:

wsvar BOSH_SERVICE = 'wss:// hostname:5280/websocket';

You should check other examples, mainly prebind and restore. Both demonstrate connection features that can help in reducing connection delay.

You will need the XMPP server installed and running. You can also use public XMPP servers, but make sure that you register with them and obtain your username (JID) and password.

You will need at least two user accounts to communicate with each other.

As we are using a web-based connection, it needs a Bidirectional-streams Over Synchronous HTTP (BOSH) extension enabled on the XMPP server. Ejabberd supports this functionality with mod_http_bind and it should be enabled by default.

Download and extract the latest source achieve from the Strophe.js site: http://strophe.im/strophejs/.

Optionally, you will need a web server set up to access a web client.

I assume the source code is located in the StropheJS directory. We will use one of the examples shipped with the StropheJS source:

Strophe.js is a JavaScript-based XMPP client library that makes it easy to write your own web-based XMPP clients. Strophe handles all actual communication parts, such as the encoding and decoding of XML stanzas, the connection procedure, and so on. You can use simple APIs provided by Strophe to create your client. Strophe.js uses jQuery to work with the HTML DOM, so if you are familiar with jQuery you will feel at home when working with Strophe.

If you browse through the code in echobot.js, you will see two main event handlers: onConnect and onMessage. These event handlers are attached to specific events and are executed when that event occurs. The onConnect handler is attached to a connection object to capture any change in connection state, and onMessage is attached as a handler for message events. It will be triggered when our client receives any message from the server.

If you are interested in the syntax for the addHandler function, it is as follows:

addHandler: function (handler,ns,name,type,id,from,options)

The handler parameter is the actual function to manipulate an incoming message object; ns is the XMPP namespace and can be used to receive packets only from a certain namespace. It defaults to jabber:client, the name parameter, which is the name of an element to act upon—in our case, it is message. You can use iq or presence to receive respective data types. Other parameters add more filtering options, where you can specify a specific ID for the message, type of the message packet (chat or normal or group, defaults to chat) and other options.

The handler function onMessage gets triggered whenever a connection object receives a new message from the server. Then, it parses the received data and extracts all required information. As it is an echo bot, it simply reads the message and echoes it back to the sender. The new message packet is generated with the following lines:

var reply = $msg({to: from, from: to, type: 'chat'})
    .cnode(Strophe.copyElement(body));

The message is passed to a connection object with the following lines, which in turn sends it to the server:

connection.send(reply.tree());

The last section initiates the Strophe client on page load (ready). When we click on the connect button, a click handler in this section gets triggered and opens a new connection with the XMPP server. The same button is changed to disconnect so that we can send a proper disconnect request to the server.

Strophe.js supports WebSocket-based XMPP connections, and the latest version of Ejabberd has also added support for WebSockets. WebSockets provides noticeable performance improvements and reduces connection time over BOSH connections. In the preceding example, we have used the BOSH protocol, which can be replaced with WebSocket simply by changing the BOSH_SERVICE URL as follows:

var BOSH_SERVICE = 'ws:// hostname:5280/websocket';

If you need a secure WebSocket connection, use the wss protocol instead of:

wsvar BOSH_SERVICE = 'wss:// hostname:5280/websocket';

You should check other examples, mainly prebind and restore. Both demonstrate connection features that can help in reducing connection delay.

I assume the source code is located in the StropheJS directory. We will use one of the examples shipped with the StropheJS source:

Strophe.js is a JavaScript-based XMPP client library that makes it easy to write your own web-based XMPP clients. Strophe handles all actual communication parts, such as the encoding and decoding of XML stanzas, the connection procedure, and so on. You can use simple APIs provided by Strophe to create your client. Strophe.js uses jQuery to work with the HTML DOM, so if you are familiar with jQuery you will feel at home when working with Strophe.

If you browse through the code in echobot.js, you will see two main event handlers: onConnect and onMessage. These event handlers are attached to specific events and are executed when that event occurs. The onConnect handler is attached to a connection object to capture any change in connection state, and onMessage is attached as a handler for message events. It will be triggered when our client receives any message from the server.

If you are interested in the syntax for the addHandler function, it is as follows:

addHandler: function (handler,ns,name,type,id,from,options)

The handler parameter is the actual function to manipulate an incoming message object; ns is the XMPP namespace and can be used to receive packets only from a certain namespace. It defaults to jabber:client, the name parameter, which is the name of an element to act upon—in our case, it is message. You can use iq or presence to receive respective data types. Other parameters add more filtering options, where you can specify a specific ID for the message, type of the message packet (chat or normal or group, defaults to chat) and other options.

The handler function onMessage gets triggered whenever a connection object receives a new message from the server. Then, it parses the received data and extracts all required information. As it is an echo bot, it simply reads the message and echoes it back to the sender. The new message packet is generated with the following lines:

var reply = $msg({to: from, from: to, type: 'chat'})
    .cnode(Strophe.copyElement(body));

The message is passed to a connection object with the following lines, which in turn sends it to the server:

connection.send(reply.tree());

The last section initiates the Strophe client on page load (ready). When we click on the connect button, a click handler in this section gets triggered and opens a new connection with the XMPP server. The same button is changed to disconnect so that we can send a proper disconnect request to the server.

Strophe.js supports WebSocket-based XMPP connections, and the latest version of Ejabberd has also added support for WebSockets. WebSockets provides noticeable performance improvements and reduces connection time over BOSH connections. In the preceding example, we have used the BOSH protocol, which can be replaced with WebSocket simply by changing the BOSH_SERVICE URL as follows:

var BOSH_SERVICE = 'ws:// hostname:5280/websocket';

If you need a secure WebSocket connection, use the wss protocol instead of:

wsvar BOSH_SERVICE = 'wss:// hostname:5280/websocket';

You should check other examples, mainly prebind and restore. Both demonstrate connection features that can help in reducing connection delay.

Strophe.js is a JavaScript-based XMPP client library that makes it easy to write your own web-based XMPP clients. Strophe handles all actual communication parts, such as the encoding and decoding of XML stanzas, the connection procedure, and so on. You can use simple APIs provided by Strophe to create your client. Strophe.js uses jQuery to work with the HTML DOM, so if you are familiar with jQuery you will feel at home when working with Strophe.

If you browse through the code in echobot.js, you will see two main event handlers: onConnect and onMessage. These event handlers are attached to specific events and are executed when that event occurs. The onConnect handler is attached to a connection object to capture any change in connection state, and onMessage is attached as a handler for message events. It will be triggered when our client receives any message from the server.

If you are interested in the syntax for the addHandler function, it is as follows:

addHandler: function (handler,ns,name,type,id,from,options)

The handler parameter is the actual function to manipulate an incoming message object; ns is the XMPP namespace and can be used to receive packets only from a certain namespace. It defaults to jabber:client, the name parameter, which is the name of an element to act upon—in our case, it is message. You can use iq or presence to receive respective data types. Other parameters add more filtering options, where you can specify a specific ID for the message, type of the message packet (chat or normal or group, defaults to chat) and other options.

The handler function onMessage gets triggered whenever a connection object receives a new message from the server. Then, it parses the received data and extracts all required information. As it is an echo bot, it simply reads the message and echoes it back to the sender. The new message packet is generated with the following lines:

var reply = $msg({to: from, from: to, type: 'chat'})
    .cnode(Strophe.copyElement(body));

The message is passed to a connection object with the following lines, which in turn sends it to the server:

connection.send(reply.tree());

The last section initiates the Strophe client on page load (ready). When we click on the connect button, a click handler in this section gets triggered and opens a new connection with the XMPP server. The same button is changed to disconnect so that we can send a proper disconnect request to the server.

Strophe.js supports WebSocket-based XMPP connections, and the latest version of Ejabberd has also added support for WebSockets. WebSockets provides noticeable performance improvements and reduces connection time over BOSH connections. In the preceding example, we have used the BOSH protocol, which can be replaced with WebSocket simply by changing the BOSH_SERVICE URL as follows:

var BOSH_SERVICE = 'ws:// hostname:5280/websocket';

If you need a secure WebSocket connection, use the wss protocol instead of:

wsvar BOSH_SERVICE = 'wss:// hostname:5280/websocket';

You should check other examples, mainly prebind and restore. Both demonstrate connection features that can help in reducing connection delay.

Strophe.js supports WebSocket-based XMPP connections, and the latest version of Ejabberd has also added support for WebSockets. WebSockets provides noticeable performance improvements and reduces connection time over BOSH connections. In the preceding example, we have used the BOSH protocol, which can be replaced with WebSocket simply by changing the BOSH_SERVICE URL as follows:

var BOSH_SERVICE = 'ws:// hostname:5280/websocket';

If you need a secure WebSocket connection, use the wss protocol instead of:

wsvar BOSH_SERVICE = 'wss:// hostname:5280/websocket';

You should check other examples, mainly prebind and restore. Both demonstrate connection features that can help in reducing connection delay.

You will need the Ejabberd server set up and running. Make sure you have enabled MUC with the mod_muc and mod_muc_admin modules.

You will need two users for the group chat. One of them needs to have admin rights to set up MUC and create rooms.

Check your XMPP client for the support of MUC or conference protocol. I will be using PSI as a client for this recipe.

For multi-user chat, we need two or more users logged in on the server at the same time, plus a chat room. Let's first set up our chat client with user accounts and create a chat room.

Follow these steps to enable group chat:

A group chat works in a similar way to a one on one chat. In a one-on-one chat, we send a message to the JID of a specific user, while in a multi-user chat we send a message to the JID of a chat room. As the message is received on room ID, XMPP takes care of forwarding it to all participants in that room.

By default, XMPP chat rooms are not persistent and will be deleted when all participants leave that room. PSI uses the default configuration to quickly create a new chat room. Once the chat room is created, you can configure it in the same chat room window. Click on the options button, the downward triangle in the upper-right corner of the chat room window, and then select Configure room:

On the first tab, you can set members, administrators, and ban user accounts. On the General tab, you can set other room configurations. You can mark a room as persistent and make it private password-protected. This tab contains a number of other options; check them at your leisure.

You may have noticed we have used an admin account to create a chat room. You can allow non-admin users to act as an MUC admin. Open the Ejabberd configuration and search for muc_admin configuration. Add your desired username below the admin entry and set it to allow.

You will need the Ejabberd server set up and running. Make sure you have enabled MUC with the mod_muc and mod_muc_admin modules.

You will need two users for the group chat. One of them needs to have admin rights to set up MUC and create rooms.

Check your XMPP client for the support of MUC or conference protocol. I will be using PSI as a client for this recipe.

For multi-user chat, we need two or more users logged in on the server at the same time, plus a chat room. Let's first set up our chat client with user accounts and create a chat room.

Follow these steps to enable group chat:

A group chat works in a similar way to a one on one chat. In a one-on-one chat, we send a message to the JID of a specific user, while in a multi-user chat we send a message to the JID of a chat room. As the message is received on room ID, XMPP takes care of forwarding it to all participants in that room.

By default, XMPP chat rooms are not persistent and will be deleted when all participants leave that room. PSI uses the default configuration to quickly create a new chat room. Once the chat room is created, you can configure it in the same chat room window. Click on the options button, the downward triangle in the upper-right corner of the chat room window, and then select Configure room:

On the first tab, you can set members, administrators, and ban user accounts. On the General tab, you can set other room configurations. You can mark a room as persistent and make it private password-protected. This tab contains a number of other options; check them at your leisure.

You may have noticed we have used an admin account to create a chat room. You can allow non-admin users to act as an MUC admin. Open the Ejabberd configuration and search for muc_admin configuration. Add your desired username below the admin entry and set it to allow.

For multi-user chat, we need two or more users logged in on the server at the same time, plus a chat room. Let's first set up our chat client with user accounts and create a chat room.

Follow these steps to enable group chat:

A group chat works in a similar way to a one on one chat. In a one-on-one chat, we send a message to the JID of a specific user, while in a multi-user chat we send a message to the JID of a chat room. As the message is received on room ID, XMPP takes care of forwarding it to all participants in that room.

By default, XMPP chat rooms are not persistent and will be deleted when all participants leave that room. PSI uses the default configuration to quickly create a new chat room. Once the chat room is created, you can configure it in the same chat room window. Click on the options button, the downward triangle in the upper-right corner of the chat room window, and then select Configure room:

On the first tab, you can set members, administrators, and ban user accounts. On the General tab, you can set other room configurations. You can mark a room as persistent and make it private password-protected. This tab contains a number of other options; check them at your leisure.

You may have noticed we have used an admin account to create a chat room. You can allow non-admin users to act as an MUC admin. Open the Ejabberd configuration and search for muc_admin configuration. Add your desired username below the admin entry and set it to allow.

A group chat works in a similar way to a one on one chat. In a one-on-one chat, we send a message to the JID of a specific user, while in a multi-user chat we send a message to the JID of a chat room. As the message is received on room ID, XMPP takes care of forwarding it to all participants in that room.

By default, XMPP chat rooms are not persistent and will be deleted when all participants leave that room. PSI uses the default configuration to quickly create a new chat room. Once the chat room is created, you can configure it in the same chat room window. Click on the options button, the downward triangle in the upper-right corner of the chat room window, and then select Configure room:

On the first tab, you can set members, administrators, and ban user accounts. On the General tab, you can set other room configurations. You can mark a room as persistent and make it private password-protected. This tab contains a number of other options; check them at your leisure.

You may have noticed we have used an admin account to create a chat room. You can allow non-admin users to act as an MUC admin. Open the Ejabberd configuration and search for muc_admin configuration. Add your desired username below the admin entry and set it to allow.

By default, XMPP chat rooms are not persistent and will be deleted when all participants leave that room. PSI uses the default configuration to quickly create a new chat room. Once the chat room is created, you can configure it in the same chat room window. Click on the options button, the downward triangle in the upper-right corner of the chat room window, and then select Configure room:

On the first tab, you can set members, administrators, and ban user accounts. On the General tab, you can set other room configurations. You can mark a room as persistent and make it private password-protected. This tab contains a number of other options; check them at your leisure.

You may have noticed we have used an admin account to create a chat room. You can allow non-admin users to act as an MUC admin. Open the Ejabberd configuration and search for muc_admin configuration. Add your desired username below the admin entry and set it to allow.

You will need access to a root account or an account with sudo privileges.

We are going to set up a Node.js-based application, so we need to install Node.js on our Ubuntu server.

Follow these steps to install Node.js:

We have set up a very simple application that listens on a given Node.js socket. To send a message, we have used the socket.emit() function, which writes the data from text box to socket:

$('form').submit(function(){
        socket.emit('chat message', $('#m').val());
        ...
});

When this message is received on the server side, the server writes it to all connected sockets, resulting in a group chat scenario:

io.on('connection', function(socket){
  socket.on('chat message', function(msg){
    io.emit('chat message', msg);
  });
}); 

Similarly, to receive a message, we keep listening on the socket, and when an event chat message happens, we write the received data to an HTML page as a message:

socket.on('chat message', function(msg){
        $('#messages').append($('<li>').text(msg));
});

This is very basic application and can be extended easily to implement one-on-one chat. All we need is a unique ID for all clients and a little modification to the interface to separate messages. Right now, the message is sent as it is; you can collect the message and create a JSON object to contain sender and receiver IDs, plus any additional information.

The advantage of using NodeJS is quick and easy development. JavaScript is a commonly used language and you can easily get support from the large community. You can always develop the application as per your requirements. The disadvantage is regarding scaling; you will need to code the clustering mechanism on your own, whereas for XMPP, clustering is implemented by nearly all leading servers.

The Node.js setup available with the Ubuntu repository is not the latest one. You can download the latest version from the node official download page.

Download NodeJS binaries for Linux. Choose your desired version by visiting the NodeJS download page. As of writing this, the latest stable version is 5.1:

$ wget https://nodejs.org/download/release/v5.1.0/node-v5.1.0-linux-x64.tar.xz

Extract binaries and move it to /use/local so that it is accessible globally:

$ tar Jxv --strip=1 -C /usr/local/

Check the node version with the following command:

$ node -v

You will need access to a root account or an account with sudo privileges.

We are going to set up a Node.js-based application, so we need to install Node.js on our Ubuntu server.

Follow these steps to install Node.js:

We have set up a very simple application that listens on a given Node.js socket. To send a message, we have used the socket.emit() function, which writes the data from text box to socket:

$('form').submit(function(){
        socket.emit('chat message', $('#m').val());
        ...
});

When this message is received on the server side, the server writes it to all connected sockets, resulting in a group chat scenario:

io.on('connection', function(socket){
  socket.on('chat message', function(msg){
    io.emit('chat message', msg);
  });
}); 

Similarly, to receive a message, we keep listening on the socket, and when an event chat message happens, we write the received data to an HTML page as a message:

socket.on('chat message', function(msg){
        $('#messages').append($('<li>').text(msg));
});

This is very basic application and can be extended easily to implement one-on-one chat. All we need is a unique ID for all clients and a little modification to the interface to separate messages. Right now, the message is sent as it is; you can collect the message and create a JSON object to contain sender and receiver IDs, plus any additional information.

The advantage of using NodeJS is quick and easy development. JavaScript is a commonly used language and you can easily get support from the large community. You can always develop the application as per your requirements. The disadvantage is regarding scaling; you will need to code the clustering mechanism on your own, whereas for XMPP, clustering is implemented by nearly all leading servers.

The Node.js setup available with the Ubuntu repository is not the latest one. You can download the latest version from the node official download page.

Download NodeJS binaries for Linux. Choose your desired version by visiting the NodeJS download page. As of writing this, the latest stable version is 5.1:

$ wget https://nodejs.org/download/release/v5.1.0/node-v5.1.0-linux-x64.tar.xz

Extract binaries and move it to /use/local so that it is accessible globally:

$ tar Jxv --strip=1 -C /usr/local/

Check the node version with the following command:

$ node -v

We are going to set up a Node.js-based application, so we need to install Node.js on our Ubuntu server.

Follow these steps to install Node.js:

We have set up a very simple application that listens on a given Node.js socket. To send a message, we have used the socket.emit() function, which writes the data from text box to socket:

$('form').submit(function(){
        socket.emit('chat message', $('#m').val());
        ...
});

When this message is received on the server side, the server writes it to all connected sockets, resulting in a group chat scenario:

io.on('connection', function(socket){
  socket.on('chat message', function(msg){
    io.emit('chat message', msg);
  });
}); 

Similarly, to receive a message, we keep listening on the socket, and when an event chat message happens, we write the received data to an HTML page as a message:

socket.on('chat message', function(msg){
        $('#messages').append($('<li>').text(msg));
});

This is very basic application and can be extended easily to implement one-on-one chat. All we need is a unique ID for all clients and a little modification to the interface to separate messages. Right now, the message is sent as it is; you can collect the message and create a JSON object to contain sender and receiver IDs, plus any additional information.

The advantage of using NodeJS is quick and easy development. JavaScript is a commonly used language and you can easily get support from the large community. You can always develop the application as per your requirements. The disadvantage is regarding scaling; you will need to code the clustering mechanism on your own, whereas for XMPP, clustering is implemented by nearly all leading servers.

The Node.js setup available with the Ubuntu repository is not the latest one. You can download the latest version from the node official download page.

Download NodeJS binaries for Linux. Choose your desired version by visiting the NodeJS download page. As of writing this, the latest stable version is 5.1:

$ wget https://nodejs.org/download/release/v5.1.0/node-v5.1.0-linux-x64.tar.xz

Extract binaries and move it to /use/local so that it is accessible globally:

$ tar Jxv --strip=1 -C /usr/local/

Check the node version with the following command:

$ node -v

We have set up a very simple application that listens on a given Node.js socket. To send a message, we have used the socket.emit() function, which writes the data from text box to socket:

$('form').submit(function(){
        socket.emit('chat message', $('#m').val());
        ...
});

When this message is received on the server side, the server writes it to all connected sockets, resulting in a group chat scenario:

io.on('connection', function(socket){
  socket.on('chat message', function(msg){
    io.emit('chat message', msg);
  });
}); 

Similarly, to receive a message, we keep listening on the socket, and when an event chat message happens, we write the received data to an HTML page as a message:

socket.on('chat message', function(msg){
        $('#messages').append($('<li>').text(msg));
});

This is very basic application and can be extended easily to implement one-on-one chat. All we need is a unique ID for all clients and a little modification to the interface to separate messages. Right now, the message is sent as it is; you can collect the message and create a JSON object to contain sender and receiver IDs, plus any additional information.

The advantage of using NodeJS is quick and easy development. JavaScript is a commonly used language and you can easily get support from the large community. You can always develop the application as per your requirements. The disadvantage is regarding scaling; you will need to code the clustering mechanism on your own, whereas for XMPP, clustering is implemented by nearly all leading servers.

The Node.js setup available with the Ubuntu repository is not the latest one. You can download the latest version from the node official download page.

Download NodeJS binaries for Linux. Choose your desired version by visiting the NodeJS download page. As of writing this, the latest stable version is 5.1:

$ wget https://nodejs.org/download/release/v5.1.0/node-v5.1.0-linux-x64.tar.xz

Extract binaries and move it to /use/local so that it is accessible globally:

$ tar Jxv --strip=1 -C /usr/local/

Check the node version with the following command:

$ node -v

The Node.js setup available with the Ubuntu repository is not the latest one. You can download the latest version from the node official download page.

Download NodeJS binaries for Linux. Choose your desired version by visiting the NodeJS download page. As of writing this, the latest stable version is 5.1:

$ wget https://nodejs.org/download/release/v5.1.0/node-v5.1.0-linux-x64.tar.xz

Extract binaries and move it to /use/local so that it is accessible globally:

$ tar Jxv --strip=1 -C /usr/local/

Check the node version with the following command:

$ node -v