AngularJS - ng-repeat to assign/generate a new unique ID

Question

Im using a simple ng-repeat to generate a list of countries. Within each list is a hidden row/div that can be expanded and collapsed.

The issue that i am facing, is that before i introduced Angular into my application, i manually hard-coded the element's ID, for example:

<li data-show="#country1">
    {{country.name}} has population of {{country.population}}

    <div id="country1">
         <p>Expand/collapse content
    </div>
</li>
<li data-show="#country2">
    {{country.name}} has population of {{country.population}}

    <div id="country2">
         <p>Expand/collapse content
    </div>
</li>
<li data-show="#country3">
    {{country.name}} has population of {{country.population}}

    <div id="country3">
         <p>Expand/collapse content
    </div>
</li>
<li data-show="#country4">
    {{country.name}} has population of {{country.population}}

    <div id="country4">
         <p>Expand/collapse content
    </div>
</li>

New code using ng-repeat:

<li ng-repeat="country in countries" data-show="????">
    {{country.name}} has population of {{country.population}}

    <div id="???">
         <p>Expand/collapse content
    </div>
</li>

How can i assign a dynamic/incremental id in my ng-repeat?

Solution 1

You can use $index https://docs.angularjs.org/api/ng/directive/ngRepeat

<li ng-repeat="country in countries" data-show="????">
    {{country.name}} has population of {{country.population}}

    <div id="country-{{$index}}">
        <p>Expand/collapse content
    </div>
</li>

Solution 2

You may need something like below when you got a nested ng-repeat:

<label id="country-{{$parent.$index}}-{{$index}}" ng-repeat="city in country.cites"> {{city.name}} </label>

Comments

[Oam Psy]

Thanks, yup i changed the template syntax.

[Eduard Gamonal]

in any case, if you are trying to identify a country to show/hide with ng-show, I'd rather add an id in your countries object. objects are unordered and using $index might not be robust sometimes

[mediaroot]

How to change the syntax? very interesting.

[Aardvark]

I removed the non-standard {[{ and }]} angular interpolation start and end symbols. This had nothing to do with the question and just made it more complicated and not general purpose. I did this on both the question and this answer. Two of the comments above were in reference to this, sorry if they make no sense now!

[Admin]

Thanks, while $index may not be robust it seems to be helpful for integration testing - which is why I looked up this option.

[Eduard Gamonal]

Hi @Iridann, $index might not be robust sometimes, e.g. if you modify the array while reading it (stackoverflow.com/questions/9882284/…) what other cases do you have in mind?

[dark_shadow]

Can anyone please take a look at this ? stackoverflow.com/questions/33190595/…