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POIs it possible to programmatically define a function from a string or some other technique without using eval()?
 

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  1. POIs it possible to programmatically define a function from a string or some other technique without using eval()?
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    <p>I am working on coding for a situation where I need to construct a function of nested callbacks of an unknown length. It is to create a sequenced animation queue to move an element across an unknown # of positions.</p> <p>For example, output would look something like this with X 'complete' callbacks nested inside:</p> <pre><code>$('#element').animate(css, { complete: function () { $('#element').animate(css, { complete: function () { // more nested calls inside } }); </code></pre> <p>Right now I am generating these functions as a string, and then once completed, feeding it to new Function():</p> <pre><code>myFunc = new Function(generatedFuncString); </code></pre> <p>The content is trusted but this still uses eval() which has negative performance implications. I was just wondering if there is another/better way?</p> <p>edit: The reason I am doing it this way is because I have a very complicated set of animations to perform and am working outside of the jQuery animation queue. If anyone has a better suggestion for how to accomplish a situation like this that would be helpful...</p> <p>Imagine a baseball diamond with a runner(A) on 1st and a runner(B) on 3rd. In one animation bundle, I want to animate runner A to 3rd (stopping at 2nd in the middle, 2 advances), and runner B to HOME (1 advance).</p> <p>I have to fire-off the initial advance with 'queue: false' so that runner A and B move to their first base at the same time (runner A to 2nd, runner B to home).</p> <p>When Runner A is done moving to 2nd, I want to then move him to 3rd (hence constructing a animate() call with nested callbacks pro grammatically to ensure this sequencing is preserved).</p> <p>The reason I am constructing the function via string is because I know what the inner-most callback is going to be first, and then recursively constructed 1 or more outer-callbacks from there. I couldn't figure out a way to do this by working with functions as objects and keeping all of the references in tact.</p> <p>Keep in mind this is a simple example. Imagine a situation where the bases are loaded, and I need to animate a grand slam (all 4 runners circle all bases, runner originating at home needs to make 3 stops before running back to home). Etc etc.</p>
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    1. COIn JavaScript, all functions are objects. Just write the function as an object (`fname = function() {...}`) and pass it wherever you need it. Anytime you think you need to use `eval()` you're probably doing things inefficiently in the first place.
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    2. COI can't imagine a scenario where such a thing is really needed. Convert a string to a function...
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      1. USgdoron
    3. COI added an edit that provides a lot more detail about the complexity of the problem.
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      1. USmattacular
 

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