Angular Directive Does Not Evaluate Inside ng-repeat

Question

Angular Directive Does Not Evaluate Inside ng-repeat

I have the following setup:

App/Directive

var app = angular.module("MyApp", []);

app.directive("adminRosterItem", function () {
    return {
        restrict: "E",
        scope: {
            displayText: "@"
        },
        template: "<td>{{ displayText }}</td>", // should I have this?
        link: function(scope, element, attrs){
            // What do I put here? I don't seem to have any
            // element to initialize (set up event handlers, for example)
        },
        compile: function(?,?,?){} // should I have this? If so, what goes inside?
    }
});

Controller

function PositionsController($scope) {
           $scope.positions = [{ Name: "Quarterback", Code: "QB" },
                               { Name: "Wide Receiver", Code: "WR" }
                              ]; 
}

HTML:

<div ng-app="MyApp">
    <div ng-controller="PositionsController">            
        <table>
            <tr ng-repeat="position in positions">
                <admin-roster-item displayText="{{ position.Name + ' (' + position.Code + ')' }}"></admin-roster-item>
             </tr>
         </table>       
    </div>
</div>

It's a very simple example, but I can't get it to render. Perhaps there's something that tutorials aren't telling me, or that is secret Angular knowledge?

If I remove the directive inside the <tr ng-repeat="..." /> and place <td>{{ displayText }}</td> instead, it will show all records.

But I want the directive to be more complicated than just a single <td>{{}}</td> (eventually) so that I could reuse this directive in multiple apps.

So, I'm really asking how do we properly create a directive that goes inside ng-repeat? What am I missing? What should be taken off from the code above?

javascript
angularjs
angularjs-directive
angularjs-ng-repeat

Answer 1

Ignoring all the theoretical aspects, you can get your code to work by making two simple changes.

don't use mixed case in your attribute names. displaytext not displayText
put the <td> tags outside the directive, in the template

Do that and it will work; it think those are both Angular bugs.

Answer 2

Agree that you need to think about where the directive begins and ends. Here's a plnkr that illustrates a directive bound to each item in the array - http://plnkr.co/edit/IU8fANreYP7NYrs4swTW?p=preview

If you want the directive to encapsulate the enumerating of a collection defined by a parent scope it gets a bit tricker. I'm not sure if the following is 'best practice', but it's how i've handled it -- http://plnkr.co/edit/IU8fANreYP7NYrs4swTW?p=preview

When relying on the directive to perform the iteration you get involved with transclusion, which is a made up word that means (as i understand it) take the content defined in the parent, push it into the directive and then evaluate it. I've been working with angular for a few months, and I'm starting to think that asking the directive to iterate is a smell, and I've always been able to design around it.

Answer 3

i think the right way to approach this would be to send the object into admin roster item, like this:

<tr ng-repeat="position in positions">
  <admin-roster-item pos="position">         
  </admin-roster-item>
</tr>

and in the directive:

var app = angular.module("MyApp", []);

app.directive("adminRosterItem", function () {
  return {
    restrict: "E",
    scope: {
        pos: "@"
    },
    template: "<td>{{ formattedText }}</td>", // should I have this?
    link: function(scope, element, attrs){
        // all of this can easily be done with a filter, but i understand you just want to     
        // know how it works
        scope.formattedText = scope.pos.Name + ' (' + scope.pos.Code + ')';
    }
  }
});

PS. i didn't test this!