scope.whenNotVisible is not a function

[jagged3dge]

Problem: scope.whenNotVisible is not a function is thrown if the when-not-visible attribute is omitted in the template markup.

Thank you for making this lovely gem of a directive. Much lighter than in-view too :)
However, here's a snag that I hit. I have this markup:

<div class="community-posts" when-visible="loadPosts">
  <!-- community post content here -->
</div>

and here's my relevant code from the controller:

var loadPosts = function ($el) {
  var posts = [{id: 1, content: 'foo bar'}, {id: 2, content: 'bar foo'}];
  return posts;
};
$scope.loadPosts = loadPosts;

But when I view the page, it throws this error in the console:

TypeError: scope.whenNotVisible is not a function

This line is where the debugger points to:

determineWhereElementIsInViewport(el, viewportHeight,
            scope.whenVisible(), scope.whenNotVisible(), delayPercent, scope);

This most likely has to do with how the reference to the whenVisible and whenNotVisible functions are passed around in the directive. If the when-not-visible attribute is omitted, scope.whenNotVisible itself remains undefined causing this error being thrown.

[rpocklin]

Thanks really appreciate the effort for this feedback, i'll take a look in detail in the next day or so.

[rpocklin]

I've fixed up the detection of these functions and updated ngdocs and bumped to v0.9.2 - here's the commit a3c190b - thanks for finding this.

[jagged3dge]

Thanks for the quick update @rpocklin

However, with the new 0.9.3 release, the issue is back, albeit at a different line. The attribute when-not-visible is not optional any more.
If I do not specify the when-not-visible attribute at all, it throws an error:

Uncaught TypeError: whenNotVisibleFn is not a function

Seems like a scoping issue. Instead of it defaulting to angular.noop, the value of whenNotVisibleFn returns undefined.

This is the line the debugger errors at:

        else if (!($el.data('hidden')) && (panelBottom < 0 || panelTop > viewportHeight)) {
          whenNotVisibleFn($el, scope); // <= this line no. 63
          $el.data('hidden', true);
        }

[rpocklin]

Apologies - see v0.9.4 for the fix. For real this time 👍

[jagged3dge]

Lovely little fix. Thanks for the quick update!