Thursday, November 29, 2007

Use ArrayCollection available in HTTPService result with caution

Please refer to this and this bug report .

Both of them speak about data editing/update not getting propagated properly through a ArrayCollection. The samples are using the ArrayCollection available from the HTTPService result directly. The HTTPService is creating the ArrayCollection first and then updating its source Array with items. The Array object doesn't dispatch any events when it is updated with new items. Due to this ArrayCollection has no way of adding event listeners for property changes to the items added later on. Hence the changes are detected only for the items present at the time of creation of ArrayCollection which happens to be 2 items.

If one desire to use the HTTP result as dataProvider and expects data updates to get properly propagated they need to create a new ArrayCollection using the source of the default ArrayCollection present in the HTTP result.

data_provider = new ArrayCollection(ArrayCollection(srv.lastResult.data.result).source);

where srv is the HTTPService. If data_provider is already a ArrayCollection then we can just modify the source as follows

data_provider.source = ArrayCollection(srv.lastResult.data.result).source;

This bug exists in Flex 2 and may not be fixed in Flex 3 as the current bug status is deffered! The source is available here and data getting loaded here.

1 comment:

madhumitha2525 said...

Hi,

Currently Iam facing an issue in flex.

Will it be possible to get the google style of implementation for tickers comparision