Data binding in general is not two-way, but an editable datagrid is a special case. It will update the dataProvider items automatically.
Tracy Spratt, Lariat Services, development services available _____ From: [email protected] [mailto:[email protected]] On Behalf Of valdhor Sent: Friday, June 12, 2009 9:42 AM To: [email protected] Subject: [flexcoders] Re: ArrayCollection and Datagrid Binding and DataProvider Question Basically, no. The datagrid is like a window into your dataprovider. If you need to modify your dataprovider you need to listem for the itemEditEnd event, grab the data that was modified and update the underlying dataprovider. The data binding will note that the dataprovider has changed and will update the datagrid on the next redraw. What data binding does is add an event dispatcher to the variable you have defined as bindable. When the variable changes an event is generated to let any component that is bound to that variable know that the variable has changed and update itself with the new data. Now, As I understand it (And I could be wrong) Flex 4 (Gumbo) does do full two way data binding. I have not read up on what or how it does this but it sounds interesting. HTH Steve --- In flexcod...@yahoogro <mailto:flexcoders%40yahoogroups.com> ups.com, Angelo Anolin <angelo_ano...@...> wrote: > > Good day. > > Learning Flex here for the past two (like three actually) weeks. Using only mxml compiler. > > I have a question with regards to the above subject: > > Assuming I declared an ArrayCollection as follows: > > [Bindable] private var _arrItems:ArrayCollection = new ArrayCollection([{"itemNo":"1", "testItem":"Angelo"}, {"itemNo":"2", "testItem":"Dinah"}]); > > This array I am binding to a datagrid as follows: > > <mx:DataGrid id="dgOutwardList" > dataProvider="{_arrItems}" > useRollOver="false" > height="450" > width="100%" > verticalScrollPolicy="auto" > sortableColumns="false" > draggableColumns="false" > resizableColumns="false"> > <mx:columns> > <mx:DataGridColumn headerText="" dataField="itemNo" width="20"/> > <mx:DataGridColumn headerText="Name of Passengers" dataField="testItem" width="200"> > <mx:itemRenderer> > <mx:Component> > <mx:TextInput width="100%" /> > </mx:Component> > </mx:itemRenderer> > </mx:DataGridColumn> > > </mx:columns> > </mx:DataGrid> > > No problem initially, as the itemNo and the testItem values are displayed properly on the datagrid. > > Now for example, if I modified my first row which contains itemNo:1 and testItem:Angelo, where I changed Angelo to Mickey, will the dataprovider reflect the change in the said row? > How do I make so that the changes in the datagrid be reflected into the ArrayCollection? such that when I changed the testItem data for the first row and access the item, via: > > _arrItems.getItemAt(arrLength -1).itemNo > _arrItems.getItemAt(arrLength -1).testItem > > The result would be "1" and "Mickey" respectively? > > I am a bit puzzled on how databinding actually works in Flex. Is it like a two-way live update (such that when you modify the value in the datagrid, it is reflected back to the arraycollection)? > > Would love to hear your inputs. > > Thanks and regards, > Angelo >
