When a developer develops templates, he/she regularly needs to use the template language and filters.
The following are the key elements of the template language:
{% autoescape on OR off %} {% endautoescape %}: This automatically starts the auto-escape feature that helps protect the browser of the displayed data (XSS).{% block block_name %} {% endblock %}: This sets the blocks that can be filled by templates that inherit from them.{% comment %} {% endcomment %}: This sets a comment that will not be sent to the user as HTML.{% extends template_name %}: This overrides a template.{% spaceless %}: This removes all the whitespaces between the HTML tags.{% include template_name %}: This includes a template namedtemplate_namein the current template. The blocks included templates that cannot be redefined.
This section shows you how to loop through a dictionary. The steps involved in looping are as follows:
{% for var in list_var %}: This allows looping in thelist_vardictionary{% empty %}: This displays the subsequent code if the dictionary is empty{% endfor %}: This indicates the end of a loop
This section shows how to execute a conditional statement:
{% if cond %}: This line checks the condition and discusses the following code when enabled.{% elif cond %}: This line checks another condition if the first has not been verified. If this condition is satisfied, the following code will be processed.{% else %}: This line will process the following code if none of the previous conditions have been validated.
The following are the different template filters:
title: This capitalizes all the first characters of each wordcut: This removes all the values of the argument from the given string, for example,{{ value|cut:"*" }}removes all the*characterslinebreaks: This replaces line breaks in text with the appropriate HTML tagsdate: This displays a formatted date, for example,{{ value|date:"D d M Y" }}will displayWed 09 Jan 2008pluralize: This allows you to display plurals, shown as follows:You have {{ nb_products }} product{{ nb_products|pluralize }} in our cart. I received {{ nb_diaries }} diar{{ nb_diaries|pluralize:"y,ies" }}.linenumbers: This displays text with line numbers at the left-hand sideescapejs: This escapes characters to use in JavaScript stringsdefault: This defines a default value if the original value equalsNoneorempty; for example, with{{ value|default:"nothing" }}, if the value is"", it will displaynothing.dictsort: This sorts the dictionary in the ascending order of the key; for example,{{ value|dictsort:"price"}}will sort the dictionary bypricedictsortreversed: This is used to sort the dictionary in the descending order of the keyfloatformat: This formats a float value, and the following are the examples:When 45.332is the value,{{ value|floatformat:2 }}displays45.33When
45.00is the value,{{ value|floatformat:"-2" }}displays45
The following are the queryset methods:
filter(condition): This method allows you to filter a queryset.none(): This method can return an empty queryset. This method is useful when you want to empty a queryset.dinstinct(field_name): This method is used to retrieve the unique values of a field.values_list(field_name): This method is used to retrieve the data dictionary of a field.get(condition): This method is used to retrieve a record from a model. When using this method, you must be sure that it concerns only one record.exclude(condition): This method allows you to exclude some records.
The following elements are the aggregation methods: