ComboBox with lazy-loading on server-side

[Adam2 (Adam Dyga)]

Hi,

The number of choices in ComboBox I’m creating is very large and it’s not advisable to load them all when the ComboBox is being created. I would rather like to send a database query only when user already enters something in the ComboBox, and populate the list of choices with query result. Is that possible with ComboBox? I thought I can populate the list after each keystroke, but I couldn’t find any way to get a server-side event after key press in the ComboBox, am I missing something?

Thanks,
AD

[joonaslehtinen]

@Adam Dyga

The number of choices in ComboBox I’m creating is very large and it’s not advisable to load them all when the ComboBox is being created. I would rather like to send a database query only when user already enters something in the ComboBox, and populate the list of choices with query result. Is that possible with ComboBox? I thought I can populate the list after each keystroke, but I couldn’t find any way to get a server-side event after key press in the ComboBox, am I missing something?

Just do setContainerDataSource(…). If your container is lazy, then ComboBox loads data lazily from the database.

[Adam2 (Adam Dyga)]

So I need to create my own Container implementation?

[joonaslehtinen]

Or use JPAContainer, HBNContainer, QueryContainer, some other existing container.

See
Container implementations in the Vaadin Directory
.

[Artur (Artur Signell)]

@Joonas Lehtinen

Just do setContainerDataSource(…). If your container is lazy, then ComboBox loads data lazily from the database.

Actually it won’t because of
#4233

[Atin (Atin Chawra)]

what is the vaadin’s recommendations on such a case where a user needs to select one item from say 1-2lacs of records. Is there a choice apart from using plugins?

[Joseph9 (Joseph Ku)]

It looks like the bug is fixed.

However, I still do not understand how I can use a lazy-loading container to populate a ComboBox based on what the user has entered in the ComboBox’s TextField.

Could someone post an example (some code, please) on how to achieve this?

Thanks,
Joseph

[Henri2 (Henri Sara)]

@Joseph Ku

However, I still do not understand how I can use a lazy-loading container to populate a ComboBox based on what the user has entered in the ComboBox’s TextField.

An old thread and no code, but just a quick comment: one of the prerequisites for being able to do server side lazy loading in for a ComboBox is that the display format of the items must be filterable by the container - e.g. the result of a Java toString() method cannot be used for filtering in a database… Use setItemCaptionPropertyId(…) to set the correct mode and property to display and to filter on.

The container must of course be able to perform lazy loading from its data source - e.g. JPAContainer, SQLContainer and LazyQueryContainer would probably work, as would suitable custom containers.

I did not check to see if all other related limitations have been addressed so that this would do full lazy loading.