<data-delete:button title="{{ '@Labels.delete: ' + currentMatrixTemplate.descrip }}" message="@String.Format(Messages.confirmDelete, Labels.matrixTemplate)" disable-action="currentMatrixTemplate.usedInItems" delete="delete()"> </data-delete:button>Update2. That indeed solved the problem. I also have a feeling I came across this one before but forgot.
<input value="Delete" type="submit" id="btnDelete" class="btn btn-danger pull-right ng-isolate-scope" ng-click="click()" ng-disabled="true" title="Delete: BASEBALL JERSEYS" message="Are you sure you want to permanently delete this Matrix Template?" disable-action="disableAction || currentMatrixTemplate.usedInItems" delete="delete()">Please note the ng-disabled="true" here.
@using Siriusware.Resources; <input value="@Labels.delete" type="submit" id="btnDelete" class="btn btn-danger pull-right" ng-click="click()" ng-disabled="{{disableAction}}" />I changed ng-disabled to use {{ a moment ago (it used to be just ng-disabled="disableAction" and didn't seem to work.