Pass Javascript element as variable

Question

I'm doing some testing for an AngularJS app, I don't think the test framework is necessarily important here, but I'm trying to pass an optional variable. This variable will specify if I'm trying to grab a child element of the ID that is passed to the function

commonFunctions.elementDoesNotHaveAttribute('register-0', 'disabled', 'children[0].children[0]');

the children[0].children[0] isn't really a string, if I remove the quotes the function call fails because it can't find a child object of .children[0]

Here is the function

function elementDoesNotHaveAttribute(id, attribute, child) {
 var hasElement = false;
 hasElement = casper.evaluate(function (id, attribute, child) {
 var element = document.getElementById(id);
 if (child) {
 element = element.child;
 } 
 return element.hasAttribute(attribute);
 }, id, attribute, child);
 if (hasElement) {
 casper.test.fail('element has' + attribute + ' but shouldn\'t');
 } else {
 casper.test.pass('element didn\'t have ' + attribute + ' and shouldn\'t');
 }
}

How can I change either side of these equations to end up evaluating element.children[0].children[0] within my function

• Jon Harding: that worked, I haven't used eval() much in the past
• Jon Harding: @T.J.Crowder, it is taking an ID, attribute, and optionally a child element. It is checking to see if that selector as the attribute that is passed or not

Answer 1

While the "eval hack" I posted in a comment will work, it's a bad idea. Instead, consider passing some kind of "transformation" function.

if( child) {
 element = child(element);
}

When calling for, say, children[0].children[0], you can do this:

commonFunctions.elementDoesNotHaveAttribute(
 'register-0',
 'disabled',
 function(e) {return e.children[0].children[0];}
);

The function will take the element and return something else related to it. Adjust the function as needed.

• T.J. Crowder: Good solution, and well done understanding the question, too. :-)
• Jon Harding: Works great, thanks for the tip. I like the solution
• T.J. Crowder: Niet, I suggest cleaning up the comments on the question. (This comment will self-destruct in five...four...three...)