Custom breakpoints for object properties in JavaScript

Question

Custom breakpoints for object properties in JavaScript

Debugging User Defined Object Properties in JavaScript

Hello there!

I'm interested in finding a JavaScript debugging tool or addon that allows me to set breakpoints on user defined object properties.

For example:

Let's say I have a JavaScript Object Literal like this:


var TextBox = {
    color:"gray",
    size:"100px",
    border:true 
}

Now, I want to be able to put a breakpoint on TextBox.color, so that I can track any modifications made to this property and identify which function is responsible for the change.

The breakpoint should trigger when:


TextBox.color = null;
or
delete TextBox.color;

Does anyone know if Firebug or Chrome Developer Tools offer this feature already?

I've come across breakpoints for HTML element removal and attribute modification, but not specifically for user defined object properties.

Thank you for your help!

javascript json debugging firebug google-chrome-devtools

Answer 1

Answer №1

Explore the fascinating world of magic getters and setters that are supported by some browsers: https://developer.mozilla.org/en-US/docs/JavaScript/Guide/Working_with_Objects#Defining_getters_and_setters

You can define a setter and set a breakpoint in it for debugging purposes.

It's advisable to avoid using these in production code due to compatibility issues, but they can be invaluable for resolving certain problems.

Answer 2

Explore the fascinating world of magic getters and setters that are supported by some browsers: https://developer.mozilla.org/en-US/docs/JavaScript/Guide/Working_with_Objects#Defining_getters_and_setters

You can define a setter and set a breakpoint in it for debugging purposes.

It's advisable to avoid using these in production code due to compatibility issues, but they can be invaluable for resolving certain problems.

Answer 3

Answer №2

Try using the following code snippet:

(function() {
    var element=TextElement; var value = element.style; 
    Object.defineProperty(element, 'style', { 
        set: function(newStyle) { debugger; value = newStyle; },
        get: function() { debugger; return value; } 
    });
})();

You can then execute this in your browser's console.

Answer 4

Try using the following code snippet:

(function() {
    var element=TextElement; var value = element.style; 
    Object.defineProperty(element, 'style', { 
        set: function(newStyle) { debugger; value = newStyle; },
        get: function() { debugger; return value; } 
    });
})();

You can then execute this in your browser's console.

Custom breakpoints for object properties in JavaScript

Answer №1

Answer №2

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