Multiple grid.appScope calls when used in cellTemplate

[wayne-chung]

I want to be able to display the result of function in a cell and for this I've used grid.appScope as per the plnkr example found at http://plnkr.co/edit/xlnjrtpg9EuL0nOG1cZy?p=preview.

I noticed the $scope.myFn function is called 60 times for the first load of just 10 results and when you scoll the grid up and down the function gets repeatly called 1000s of time (you can see this in console).

In my case, I want the grid.appScope function to get data from an $http request which becomes problematic with the repeated calls.

Is there anyway to prevent the mutliple calls so each cell calls the grid.appScope function only once?

Are there any other solution other than using grid.appScope?

[JLLeitschuh]

If you are using angular 1.3.* you could try out one time bindings. https://docs.angularjs.org/guide/expression (Look under One-time binding)
Weirdly enough though, when I try your plnk and none of the data is virtualized I still see thousands of calls when I scroll up. My demo: http://plnkr.co/edit/QT13I22GqF1Fsv3Ifo3L?p=preview

[wayne-chung]

Tried one time binding http://plnkr.co/edit/5QF7TlM5qf6dWtrbEKd6?p=preview. It stopped the calls when scrolling but the function is still called 20 times for 10 rows. As mentioned before, I'm want to use Grid.appScope to get results from $http requests and these can be really slow in some cases(summing multiple thousands of rows from a database).

As for your demo, I can't see the difference between your and mine plnkr as the code looks exactly the same. Wrong link?

[wayne-chung]

I was able to achieve what I want using a directive rather than grid.appScope as per the example: http://plnkr.co/edit/p9V8icvIwa7yzUHqD7Rz?p=preview. The directive controller is called once per cell.

It would be nice if the developers could take a look at the mutliple call issue with grid.appScope as I think users expects it to be called only once?

[JLLeitschuh]

Thats not how watches work. They are designed to cause the DOM to update as soon as the data behind them changes. Someone else want to weigh in on this? @swalters @AgDude @c0bra

[c0bra]

In the interim you could set cache: true on your $http call, but that definitely looks like WAY too many digests are happening during load and scroll. It will take some debugging to see why.

[PaulL1]

What version are you on? There are definitely a lot of digests, that's been an ongoing problem, although I think a number of them went away in rc21 or rc22.

If I were doing an http call from a cell template, I'd be writing a cache into my function - so I'd only do the http call if I hadn't already cached the result. That'd give you what you want. Even if we were doing only the minimum digests, it'd still be more than the number of http calls you'd want - as we scroll we destroy and recreate cells, so at a minimum it'll do the http call once for each cell as you scroll down, then once again for each cell as you scroll up, and that's too many.

[wayne-chung]

I'm using rc21. The plnkr examples I've given is pointing to http://ui-grid.info/release/ui-grid-unstable.js so it appears there were no change from rc21 to r22. Angularjs version is 1.3.14.

[chanont-poon]

I'm using ui-grid v3.1.1 and still facing the same issue. Additionally, I've noticed that when I assign the function to columnDefs's field, it's also called multiple times. After wrapping the data assignment inside $timeout, it helps a little.
$timeout(function() { gridOptions.data = data; });

But the function is still called on each cell. Any update on this issue?