Chrome debugger inject javascript

Question

I have this curiosity,

Is it, in some way, possible to inject javascript in my page and execute it and debug it? As you do with the console, but in the console you can't pause and watch variables.

Is it possible to debug code that i put through console? Why isn't it possible to debug code received via XHR?

Thanks!

Mohamed Mansour · Accepted Answer · 2011-03-11 13:10:23Z

12

One trick I learned today from Chromium is that if you place the word:

debugger;

Right before the statement you want to debug. It will break on the debugger. It is really useful for injected scripts.

answered Mar 11, 2011 at 13:10

Mohamed Mansour

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2 Comments

Andr Over a year ago

But this word must be placed there before paged is fetched. Does it work if you put it with edit? Anyway, how do you debug on XHR?

Mohamed Mansour Over a year ago

The exact same way. In your code that your injecting, you place that word that is the only way you can debug using debugger.

Sakthi · Accepted Answer · 2011-03-11 13:22:11Z

0

yes, its possible to include the javascript function in our webpage by using

window.onload = function fun(){alert("test");}

with in this event u can give a statement or any function.

answered Mar 11, 2011 at 13:22

Sakthi

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4 Comments

Andr Over a year ago

Yes, but this occurs only once. I want to put code after my page is loaded and understand it in the debugger. Nice trick, though.

Sakthi Over a year ago

s brother u give your code with in the function or in onload event. your code will execute at the end of your page load.

Andr Over a year ago

yea. but it don't want to be executed only at pageload. I want to: copy paste a code and execute it based on the data of the page.

Sakthi Over a year ago

k.. if your executing the based on the data, u must check the html element. u do the same here also brother. by using these script var spanArray = document.getElementsByTagName('span'); alert(spanArray[0].innerHTML);

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