CODEWITHSUNDEEP
angularjsangularjs-directive
core
core

Reputation: 33087

Conditionally adding data-attribute in Angular directive template

I'm working on the template for a directive. If a property in the scope is set to true, data-toggle="dropdown" should be appended to the element. If the variable is false, this data attribute should not render as an attribute of the element.

For example, if scope variable is true, the template should render:

<span data-toggle="dropdown"></span>

If false, the template should render:

<span></span>

What would the template look like to accomplish this?

For example, I know that I can use ng-class to conditionally include a class. If I want the template to render this:

<span class="dropdown"></span>

Then my template would look like this:

"<span ng-class="{ 'dropdown': isDropDown }"></span>

If scope variable isDropDown is false, then the template will simply render:

<span></span>

So there's a way in a template to conditionally add a class="dropdown". Is there a syntax for templates that allows me to conditionally add data-toggle="dropdown"?

One of the things I've tried for the template is:

"<span data-toggle="{ 'dropdown': isDropDown }"></span>

My thinking with the above template is that if the scope variable isDropDown is true, the value of data-toggle will be set to "dropdown". If isDropDown is false, then the value of data-toggle would simply be an empty string "". That doesn't seem to work though.

Upvotes: 65

Views: 96624

Answers (3)

Garfi
Garfi

Reputation: 545

<span ng-attr-data-toggle="{{isTrue && 'dropdown' || undefined }}"></span>

will produce when isTrue=true : <span data-toggle="dropdown"></span>

and when isTrue=false : <span></span>

Upvotes: 42

Aurelio
Aurelio

Reputation: 25822

I think a good way could be to use ng-attr- followed by the expression you want to evaluate. In your case it would be something like:

<span ng-attr-data-toggle="{{ isValueTrue ? 'toggle' : 'notToggle' }}"></span>

Here's a fiddle with an example.

Upvotes: 86

Wawy
Wawy

Reputation: 6269

At the moment, there is no angular directive that allows you to remove or add an attribute conditionally. You can do ng-switch around the span, one with that attr and another one without it.

<div ng-switch on="condition">
<span data-toggle="dropdown" ng-switch-when="value"></span>
<span ng-switch-default></span>
</div>

or

<span data-toggle="dropdown" ng-if="expression"></span>
<span ng-if="!expression"></span>

You can also create a directive for that same purpose (adding/removing attrs conditionally) but that would be a bit more complicated.

Additionally if what you want is manage the scope variable inside the directive you can pass it as another attribute.

Example:

<span data-toggle="dropdown" when="isDropDown"></span>

Upvotes: 8

Related Questions