Migrator.OnDowngrade(Int32, Int32, GenericDocument) Method
Definition
Important
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Migrates GenericDocument to an older version of AppSearchSchema.
[Android.Runtime.Register("onDowngrade", "(IILandroid/app/appsearch/GenericDocument;)Landroid/app/appsearch/GenericDocument;", "GetOnDowngrade_IILandroid_app_appsearch_GenericDocument_Handler", ApiSince=31)]
public abstract Android.App.AppSearch.GenericDocument OnDowngrade (int currentVersion, int finalVersion, Android.App.AppSearch.GenericDocument document);[<Android.Runtime.Register("onDowngrade", "(IILandroid/app/appsearch/GenericDocument;)Landroid/app/appsearch/GenericDocument;", "GetOnDowngrade_IILandroid_app_appsearch_GenericDocument_Handler", ApiSince=31)>]
abstract member OnDowngrade : int * int * Android.App.AppSearch.GenericDocument -> Android.App.AppSearch.GenericDocumentParameters
- currentVersion
- Int32
The current version of the document's schema.
- finalVersion
- Int32
The final version that documents need to be migrated to.
- document
- GenericDocument
The GenericDocument need to be translated to new version.
Returns
A GenericDocument in new version.
- Attributes
Remarks
Migrates GenericDocument to an older version of AppSearchSchema.
This method will be invoked only if the SetSchemaRequest is setting a lower version number than the current AppSearchSchema saved in AppSearch.
If this Migrator is provided to cover a compatible schema change via AppSearchSession#setSchema, documents under the old version won't be removed unless you use the same document ID.
This method will be invoked on the background worker thread.
Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.