I trying to get the target element's id when function fired, but `this` keyword returns `undefined`

Question

I trying to capture the target element's id when function fired, but this keyword returns undefined

--- HTML file. --- (I can't add any parameter in onclick function) I have many <a> tag in the page and want to identify witch <a> tag was clicked.

<a href="#some_links" id="element_id" onclick = "object.pageName.functionName('parms1', 'parms2', 'parms3')">Get this object</a>

<a href="#some_links" id="second_element_id" onclick = "object.pageName.functionName('parms1', 'parms2', 'parms3')">Get this object</a>

--- .js file ---

object.pageName.functionName = function(a, b, c){
    alert(this); // returns 'undefined'
}

Just path this in params http://stackoverflow.com/questions/4825295/javascript-onclick-get-the-id-of-the-button-clicked — webdeveloper, Sep 19 '12 at 07:23

Jeremy J Starcher · Accepted Answer · 2012-09-19T07:37:17.753

3

This is a very common question here on StackOverflow.

In short, your onclick gets wrapped in an anonymous function (which does have access to this. You have to pass it along.

--- HTML file. ---

<a href="#some_links" id="element_id" onclick = "object.pageName.functionName(this, 'parms1', 'parms2', 'parms3')">Get this object</a>

--- .js file ---

object.pageName.functionName = function(self, a, b, c){
    alert(self); // returns 'undefined'
}

Here is another way:

object.pageName.functionName = function(a, b, c){
    // Downside of this way, you can only use this function for one element.
    self = document.getElementById("element_id");
    alert(self);
}

edited Sep 19 '12 at 07:37

answered Sep 19 '12 at 07:22

Jeremy J Starcher

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I am not able to add 'this' parameter in the onclick function. – Krishna Kumar Sep 19 '12 at 07:34
Question -- I'm curious as to what kind of work environment asks you to do a job but doesn't give you the power to do it. Answer updated, BTW. – Jeremy J Starcher Sep 19 '12 at 07:38
this works for only one anchor, but what if there are many tag in the page and need identify witch tag was clicked. – Krishna Kumar Sep 19 '12 at 07:42
There is only one correct solution: Pass `this` as a parameter. If you can't do that, then you'll have to find another solution based off what I gave you. I've shown you the problem. I've told you the solution **and** I've given you a work-around. – Jeremy J Starcher Sep 19 '12 at 07:46

I trying to get the target element's id when function fired, but `this` keyword returns `undefined`

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