insert javascript function in html code

Question

I need to associate a dynamic javascript function with checkbox along with other data in an array. For example. I have the following javascript array:

var arr = ['hello', 'world'];
arr.unshift('buddy');
var index = 1;
arr.unshift('<input type="checkbox" id = "' + index + '" onchange="boxChange(" + index + ")>');

The first element in the above array is a checkbox that has an onchange event. The event triggers the function boxChange that has the index passed in.

but the above checkbox event doesn't work, I guess the syntax (quotes) is not right. I need some help with correcting the "quotes". Thanks

I have an imcomplete code written in jsFiddle here http://jsfiddle.net/qq0dsz0f/

is there a reason for inline event handlers rather then in a unobtrusive style? — atmd
– atmd, Commented Jan 6, 2015 at 14:59
it looks like you already know how to concatenate a string in js, so do the same for second index variable. But your quotes are mismatching anyway... — A. Wolff
– A. Wolff, Commented Jan 6, 2015 at 15:00
Inspect the html itself in console, will see your quotes are breaking. Use proper escaping and matching. The syntax highlighting of code in your question should also be a clue — charlietfl
– charlietfl, Commented Jan 6, 2015 at 15:01

Community · Accepted Answer · 2017-05-23 11:57:54Z

1

Generally speaking, mixing markup and logic is not a good idea. You can see for yourself -- as soon as you start wanting to manipulate the DOM in non-trivial ways, things get really hairy, really fast. You shouldn't have to worry about getting your quotes right, and you don't have to!

jQuery allows you to create an element on its own, then attach various event handlers to it and then store it, add it to your document, etc.

// First, let's create the element itself.
var element = $('<input type="checkbox" id="' + index + '">");

// Now, let's attach the logic.
element.on('change', function() {
    alert(index);
});

// Now do whatever you want with 'element'.

Isn't this syntax much cleaner?

Secondly, if you happen to use this inside a loop, you might get some strange behavior because of how the function captures the value of `index'. If this is the case you might want to see this question on capturing variables in JavaScript.

edited May 23, 2017 at 11:57

CommunityBot

11 silver badge

answered Jan 6, 2015 at 15:07

Andrei Bârsan

3,5312 gold badges26 silver badges48 bronze badges

Sign up to request clarification or add additional context in comments.

7 Comments

prodigitalson Over a year ago

Actually it could get even cleaner if you used a delegate. Then you only need to attach the handler once: $('#table1').on('change', 'input[type="checkbox"]', function (e) { alert($(this).attr('id')); }

Andrei Bârsan Over a year ago

That's an even cleaner one. Neat!

prodigitalson Over a year ago

Additionally you should mention he cannot use only a number for (ie. the index) for his id attribute... it needs to start with a letter... so something like checkbox-1 would be fine but just 1 is not.

charlietfl Over a year ago

@prodigitalson that's not true in html5 spec, numeric ID's are allowed

prodigitalson Over a year ago

@charlietfl interesting... I did not know that. I haven't actually reviewed the spec in full just some of the newer features. Very good to know though for the record I think i would avoid it without a prefix it could get confusing with nothing else in the id.

|

Collectives™ on Stack Overflow

insert javascript function in html code

1 Answer 1

7 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

7 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related