topic Re: One arraycollection for 2 widgets in ArcGIS Viewer for Flex Questions

One arraycollection for 2 widgets

AaronPerry — Wed, 01 May 2013 19:51:00 GMT

I have 2 widgets that need to share an arraycollection. I want to create the collection once in which ever widget initializes first, and then store it for them both to use from that point forward. I've looked at DataManager and I can see how I would share data in an event driven way. What I don't see is a way to store data in DataManager when either widget initializes and 1) check for the data's existence when the second widget loads so I don't have to create it again, and 2) how I would retrieve the stored data in the second widget if I could check for its existence in DataManager.

For reference, the driving force here is that I have comboboxes in each widget that need to use the same data.

Can anyone explain how I would share a single collection of data between widgets that only gets initialized once?

Any help would be greatly appreciated.

Thanks,
Aaron

Re: One arraycollection for 2 widgets

KennyHoran — Thu, 02 May 2013 17:43:20 GMT

I've been there. It's a bit hard to visualize but it's possible to share data. Let's see if I can explain it.

When the data is initialized you should dispatch a DATA_PUBLISH event containing the data. Each of your widgets should listen for that event, then save a copy of the data.

But what if the DATA_PUBLISH happens before your widget is initialized? For that you'll need the DATA_SENT event. Dispatch a DATA_FETCH to trigger it, then it will return the DATA_PUBLISH results if they exist.

So, by using DATA_PUBLISH and DATA_SENT you can share data between widgets regardless of where or when it originates.

Re: One arraycollection for 2 widgets

DougBrowning — Fri, 03 May 2013 13:05:08 GMT

When I had to do this I just "cheated" and used a global var. It was just so much easier.

Re: One arraycollection for 2 widgets

AaronPerry — Fri, 03 May 2013 18:45:36 GMT

Thanks so much Kenny. This is what I needed to hear. I had seen a lot of posts about sharing data with DataManager, but this made it click after careful consideration of your explanation. I may post some basic code here later to help others who need help trying to "visualize" it.

Re: One arraycollection for 2 widgets

RobertScheitlin__GISP — Fri, 03 May 2013 20:08:57 GMT

All,

Here is a thread and a PDF explaining widget communication:

http://forums.arcgis.com/threads/38899-Widget-Communication-Explained

Re: One arraycollection for 2 widgets

AaronPerry — Mon, 06 May 2013 12:44:46 GMT

Thanks so much Robert! That is a great document. I am lost as to why my plethora of searches on the subject here did not yield that thread.

Thanks again all.