Adobe 65007312 Programming Guide - Page 69

CHAPTER 4: Working with Metadata Adding custom metadata 69 Defining metadata fields The script for your Metadata Provider defines specific metadata fields. The metadata definition script returns a table that describes the fields to be added to Lightroom's metadata schema. It contains the following fields: metadataFieldsForPhotos table schemaVersion number updateFromEarlierSchemaVersion function noAutoUpdate Boolean Required. Defines new data fields to be stored for each photo. The table is an array of field definitions. Each entry in the metadataFieldsForPhotos array describes a single field which can be associated with photos in the catalog. Each field can hold only one value per photo. See "Metadata field entries" on page 70. Required. Allows for versioning of the property definition schema. Typically this number starts at 1 and you increment it whenever you release a new version of the schema or need to run the update function. Optional. Allows your plug-in to update data when a new schema version is in place. The function takes three parameters; catalog, previousSchemaVersion, and progressScope. When the plug-in is first installed, previousSchemaVersion is nil. See example below. Optional. When false (the default), Lightroom attempts to automatically update metadata from old field definitions to new. If you prefer to handle this in your own plug-in (using the updateFromEarlierSchemaVersion callback), set this to true.