Move template string in directive to html file (enhancement)

[nvernooy]

Is it possible to move the template string used in the directive for the treeview to an external html file?
I'm trying to do this myself but running into some trouble. So far I've moved the attrs variables to scope and my html looks like this:

<ul>
    <li data-ng-repeat="node in treeModel">
        <i class="collapsed"
            data-ng-show="node.nodeChildren.length && node.collapsed"
            data-ng-click="selectNodeHead(node)">
        </i>
        <i class="expanded"
            data-ng-show="node.nodeChildren.length && !node.collapsed"
            data-ng-click="selectNodeHead(node)">
        </i>
        <i class="normal"
            data-ng-hide="node.nodeChildren.length">
        </i>
        <span class="treenode node.nodeType"
            id="node.nodeId"
            data-ng-class="node.selected"
            data-ng-click="selectNodeLabel(node)">
            {{node.nodeLabel}}
        </span>
        <div data-ng-hide="!node.collapsed"
            data-tree-model="node.nodeChildren"
            data-node-id="nodeId"
            data-node-label="nodeLabel"
            data-node-children="nodeChildren"
        </div>
    </li>
</ul>

I had to take the treeId out, and the treeModel is being treated as string, I'm not sure why. Any help or comments would be appreciated.