Fix missing expand/collapse tree icon when refreshing page

[rasmusjp]

Prerequisites

• I have written a descriptive pull-request title
• I have linked this PR to an issue on the tracker at http://issues.umbraco.org/issue/U4-10499

Description

This fixes expand/collapse tree icons not being shown in the navigation tree when the page is refreshed

Before:

After:

[emmaburstow]

Thanks for this one too @rasmusjp! We'll look over it shortly.

Emma, Community Pull Request team

[emmaburstow]

Hi @rasmusjp

This is ace for two reasons. One, you've made ten lines of code into one and it does the job nicely. Two, this had been bothering me too ;)

I've tested it and am happy to approve. Thanks for your work,

Emma

[madsrasmussen]

It is absolutely amazing we are getting closer to fix this issue because it is a little bit annoying.

One thing we have to keep in mind before merging: The reason why we moved the logic from the template to the link function was part of a performance improvement. If you have many nodes in the tree a lot of watchers can bring Angular to its knees. The PR will bring back an "ng-style" which might be okay but it will add to the numbers of watchers on the tree.

[rasmusjp]

@madsrasmussen Sure, I'll gladly look into solving this another way. But looking at the history ng-style haven't been used before. If there might be a performance problem with ng-style wouldn't it also happen for ng-class and ng-show which also are used in the template?

From what I can see the problem occurs in the first place because loadNodeChildren() calls removeChildNodes() which sets hasChildren to false.

So maybe adding a way to trigger a "node refresh" when loadNodeChildren has finished would be better.

Please let me know if I should look into doing that instead

[rasmusjp]

I've updated the PR, so now instead of adding ng-style we just call updateNodeData on the node instead, which updates the dom node. This is the same thing that's being done when the node is reloaded. Not sure how I've missed that function in the first place.

This shouldn't have any impact on the performance on large trees and the result should be the same.

@emmaburstow , would you have a look again and verify it still works as expected?

[emmaburstow]

hi @rasmusjp!

Sure, I'll have a look tonight :) Thanks for that

Emma

[emmaburstow]

Hi @rasmusjp - all good here at my end! @madsrasmussen are you happy with the changes?

[madsrasmussen]

Awesome! If all tests are OK then I think we are good to go 🎉

[nul800sebastiaan]

Great stuff! Thanks @rasmusjp 👍