Sign In Start Free Trial
Account

Add to playlist

Create a Playlist

Modal Close icon
You need to login to use this feature.
  • Book Overview & Buying DART Cookbook
  • Table Of Contents Toc
  • Feedback & Rating feedback
DART Cookbook

DART Cookbook

By : Ivo Balbaert
4 (2)
close
close
DART Cookbook

DART Cookbook

4 (2)
By: Ivo Balbaert

Overview of this book

If you are a Dart developer looking to sharpen your skills, and get insight and tips on how to put that knowledge into practice, then this book is for you. You should also have a basic knowledge of HTML, and how web applications with browser clients and servers work, in order to build dynamic Dart applications.
Table of Contents (13 chapters)
close
close
12
Index

Debugging your app in JavaScript for Chrome

In this recipe, we will examine how to debug your app in the Chrome browser.

How to do it…

  1. From the menu in the upper right-hand corner, select Tools and then Developer Tools.
  2. Verify via Settings (which is the wheel icon in the upper right corner of the Developer Tools section) that the Enable JavaScript source maps option is turned on. Make sure that debugging is enabled, either on all the exceptions or only on uncaught exceptions.
  3. Choose Sources in the Developer Tools menu, then press Ctrl + O to open a file browser and select the Dart script you wish to debug.

    Note

    Clicking on the left margin before a line of code places a breakpoint, which is indicated by a fat blue arrow.

  4. Now reload the application and you will see that the execution stops at the breakpoint. On the right, you have a debug menu, which allows you to inspect scope variables, watch the call stack, and even create watch expressions, as shown in the following screenshot:
    How to do it…

    Debugging JS in Chrome

How it works...

Chrome uses the source map file <file>.js.map generated while compiling the JavaScript code to map the Dart code to the JavaScript code in order to be able to debug it.

There's more...

In this recipe, we will examine how to debug your app in the Firefox browser.

Debugging your app in JavaScript for Firefox

In Firefox, the source maps feature is not yet implemented. Use Shift + F2 to get the developer toolbar and the command line. In the top menu, you will see Debugger. Place a breakpoint and reload the file. Code execution then stops and you can inspect the value of the variables, as shown in the following screenshot:

Debugging your app in JavaScript for Firefox

Debugging JS in Firefox

Visually different images
CONTINUE READING
83
Tech Concepts
36
Programming languages
73
Tech Tools
Icon Unlimited access to the largest independent learning library in tech of over 8,000 expert-authored tech books and videos.
Icon Innovative learning tools, including AI book assistants, code context explainers, and text-to-speech.
Icon 50+ new titles added per month and exclusive early access to books as they are being written.
DART Cookbook
notes
bookmark Notes and Bookmarks search Search in title playlist Add to playlist font-size Font size

Change the font size

margin-width Margin width

Change margin width

day-mode Day/Sepia/Night Modes

Change background colour

Close icon Search
Country selected

Close icon Your notes and bookmarks

Confirmation

Modal Close icon
claim successful

Buy this book with your credits?

Modal Close icon
Are you sure you want to buy this book with one of your credits?
Close
YES, BUY

Submit Your Feedback

Modal Close icon
Modal Close icon
Modal Close icon