.prop的JQuery typescript定义？

Question

I have the following code:

// Populate the title of the selects on change and trigger a change
$('#modal .update-title')
    .change(function () {
        var $select = $(this),
        match = null,
        matchRow = null,
        title = $('option:selected', this).prop('title');

In typescript this sets the value of title to a bool. Then when I try and use it as follows I am getting an error:

$("#modal_Title_" + matchRow).val(title);

Is this another problem with the JQuery definition or something that I am doing wrong? When a check the definition file I see the following:

prop(propertyName: string): bool;

This does not seem to match the JQuery doc.

Answer 1

The jQuery documentation is incorrect, and so is your type definition file.

Most properties are strings, but some are numbers (eg .selectedIndex ) and some are booleans ( .checked etc), and $.fn.prop() does not convert them all to strings.

The correct definition should be:

prop(propertyName: string): any;

There's already a work item listed on the TypeScript site to fix this.

Answer 2

As @Alnitak pointed out, the return value should be 'any'.

I have fixed the jQuery definitions file at DefinitelyTyped which is a fork from TypeScript's file, but with numerous fixes.

Answer 3

The jQuery docs state that prop returns:

• a string when called with one argument

• a jQuery object when called with two arguments

http://api.jquery.com/prop/

So according to this the jquery.d.ts may be incorrect.

My recommendation would be to edit the jquery.d.ts to be correct in your project and raise a bug at typescript.codeplex.com

prop(propertyName: string): string;