Hi people
How do you do a ComboBox, like a DBlookupComboBox in VCL, in a FireMonkey? Someone is using FireMonkey+LiveBindings+TAureliusDataSet to implemente a DBLookupComboBox?
Thanks
which version of Delphi? It changes a lot from version to version.
To work with Firemonkey you need to be using XE5 and better XE6 where many bugs are corrected.
Do you need to lookup from another database? or from a List?
Considering XE5/XE6
Lookup from another database:
Combobox Livebinding options:
SelectedValue -> connect to your main dataset where the selected value will be defined
Item.Text -> connect to the auxiliary dataset for the text that will be displayed
Item.LookUpData -> connect to the auxiliary dataset for the value that will be used on SelectedValue when the user select the item on the list
this is very simple, you need to use TAureliusDataset.
For look up on a list is much more complicated. To simplify that I am using VitualTable from DevArt (they have free version) that is a memory table, you load with the items you need on it and follow the same idea above, then you can have any kind of lists like that.
Remember that for the TAureliusDataSet you need to drop a BindSource on your form and connect it to the TAureliusDataSet. It is the BindSource that you use for connection.
THis is all regular Delphi LiveBinding guideline, there is samples in your delphi installation and webpages about that.
Hi Eduardo
Let's say you have:
TAureliusDataSetUser with 'Self','Id','Name' and 'UserGroupId' fields, 'UserGroupId' type TAureliusEntityField.
The auxiliar DataSet, TAureliusDataSetUserGroup with 'Self','Id','Description'.
ComboBox.SelectedValue -> connect to TAureliusDataSetUser.UserGroupId (is this correct?)
ComboBox.Item.Text -> connect TAureliusDataSetUserGroup.Description
ComboBox.Item.LookUpData -> connect to TAureliusDataSetUserGroup.Self (is this correct?)
when you call User.Get(server method), you receive on client side
Example of TAureliusDataSetUser Data:
Self = 123487, Id=1, Name= Joo, UserGroupId=546972 (TAureliusEntity)
when you call UserGroup.Get(server method), you receive on client side
Example of TAureliusDataSetUserGroup Data:
Self =845645, Id=1, Description='Big Group'
Self =657697, Id=2, Description='Small Group'
As you see, the TaureliusDataSetUser.UserGroupId differs from TAureliusDataSetUserGroup.Self (i understand that), how they will be linked?
What i'm missing?
thanks a lot, for your time
You must be sure users and groups retrieved are in the same manager, the >instance< of the objects must be the same. Your user is pointing to a group object, but your list of groups have different instances.
Hi, Wagner
Ok, only have a Manager on de server side, so i have User.Get(server methiod) and UserGroup.GetAll(server method), to load TaureliusDataSetUser i call User.Get from de server and
to load TAureliusDataSetUserGroup i call UserGroup.GetAll, in this case i have to load TaureliusDataSetUser and TaureliusDataSetUserGroup on de same call to the server method, that's it?
Thanks,
P.S. I'm using XE5, DataSnap Rest Server + JSON + Aurelius and FireMonkey+LiveBinding+TAurelius DataSet on client side.
Yes, you should do that. Or, after loading both lists, you have to update your User.GroupId instance to point to one of the instances of the list loaded by UserGroup.Get (find by id).
Ok, my server methods result a TUser Object(JSON) and a TUserGroup (JSON), if i make just one call "TUser.Get", my server method result what?
1- A TUser with Many-Value-Association to TUserGroup, like master-detail?
2- and in client side how to load TaureliusDataSetUser and TAureliusDataSetUserGroup?
3- How to refresh TuareliusDataSetUserGroup when TAureliusDataSetUser is in Edit ou Insert?
"Or, after loading both lists, you have to update your User.GroupId
instance to point to one of the instances of the list loaded by
UserGroup.Get (find by id)."
that's what i'm doing now, but i have the same question:
How to refresh TuareliusDataSetUserGroup when TAureliusDataSetUser is in Edit ou Insert?
Thanks, sorry to be so persistent, but i have to find the best solution to do that,
thanks again Wagner
The refresh is just as with any TDataset descendant, if you call Refresh, it will Post or Cancel the record then refresh. This is standard TDataset behavior.
For now forget the refresh :), and what about the "1 call" solution?
Thanks
I don't know how your server works. But maybe you could just use the second approach, which is "unify" the instances by the id.