Voyager supports metadata extraction from standard XML documents using XPath queries. It not only supports many standard metadata specifications out of the box, but also allows you to enter your own XPath queries to specific metadata elements and map them to searchable field names within Voyager's index. These field names can exist already, or be created on the fly. This topic provides an overview of the Voyager Metadata Extraction page, explains how to define XPath queries to metadata elements, and how to specify field mapping parameters.
Access to To access the Metadata Extraction page is in , open Voyager Server’s Manage UI : and go to Manage Voyager > Discovery > Pipeline > Metadata.
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Testing Your Mapping
To map the fields, configure these parameters:
Choose the Selector: This specifies XPath query to a specific metadata record element to be selected.
Enter the Field Name: This is the target field in Voyager that gets mapped to the specified metadata output.
Confirm the Type: This refers to the data type of the field name. For example, if field name is set to “name”, data type automatically gets set to “text.”
Choose an Action: Users can select from five different functions:
Set Field— Assigns value to the specified field
Append Field—Adds to/modifies pre-existing field
Set Geo—Sets a geographic bounding box based on coordinates specified in the metadata
Expand Geo—Expands geographic bounding box from previously set coordinates
Add Link—Helps point field to a URL
Converter - Converter settings are optional and if the user does not specify one, Voyager, by default, assigns an appropriate converter to the field.
Bbox -- Converts bounding box values contained in the XML document
Gml_Geometry -- Converts geometric (line, circle etc) coordinates from the XML document
Date -- If the Date field is represented as a string value in the XML document, this converts it into a standard date format
String256 -- Finds a String within the element with a maximum length of 256 characters
String512 -- Finds a String within the element with a maximum length of 512 characters
StringValue -- Finds a String (of any length) within the element
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For example, here the Field Name is City, whose data type is String.
NoteNOTE: when selecting a field name you'll need to either select an existing field name or you can also enter a custom field name as long as it uses a prefix "meta_", "id_".
Step 4: Click Test. The The extractor searches the XML document for the queried metadata element, and retrieves the value for the field City. The results are presented in the Output tab.
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