templateUrl function is not using explicit annotation and cannot be invoked in strict mode

Question

I'm attempting to create a custom angular component that dynamically loads a template based on a templateUrl function. I currently get a templateUrl is not using explicit annotation and cannot be invoked in strict mode' error. Normally I understand that this error crops up when an injected service doesn't get properly annotated (https://docs.angularjs.org/error/$injector/strictdi). However, I am missing how this applies to templateUrl.

I'm using Angular 1.5.

Exact error message is - angular.js:13550 Error: [$injector:strictdi] templateUrl is not using explicit annotation and cannot be invoked in strict mode

Component Code snippet:

angular.module('hive.triGrid')
.controller('TriGridCellController', ['$element', '$attrs', function     ($element, $attrs) {
    var $ctrl = this;
}]) 
.component('triGridCell', {
controller: 'TriGridCellController',
templateUrl: function($element, $attrs)
{
    var type = $attrs.cellType;
    if(type.toUpperCase() == "ICON")
    {
        return "components/grid/cellTemplates/iconCell.tpl.html";
    }
    else if(type.toUpperCase() == "CUSTOM")
    {
        return $attrs.cellTemplateUrl;
    }
    else
    {
        return "components/grid/cellTemplates/textCell.tpl.html"; 
    }
},
//template:"<ng-include src='$ctrl.getTemplateUrl(z)'/>",
bindings: {
    cellData:'<',
    cellType: '<', //See triGridRow and triGrid for config JSON format.
    }
});

EDIT: Code after answer was applied:

templateUrl: ['$element', '$attrs', function($element, $attrs)
{
    var type = $attrs.cellType;
    if(type.toUpperCase() == "ICON")
    {
        return "components/grid/cellTemplates/iconCell.tpl.html";
    }
    else if(type.toUpperCase() == "CUSTOM")
    {
        return $attrs.cellTemplateUrl;
    }
    else
    {
        return "components/grid/cellTemplates/textCell.tpl.html"; 
    }
}],

Answer 1

As said in this answer, $element and $attrs are injected into templateUrl function, not just passed as arguments. This is the difference between element parameter name (in link or compile functions) and $element local dependency in DI-enabled functions that Angular documentation emphasizes.

templateUrl function is invoked by injector in components, so any other services can be injected there as well, and it should be properly annotated.