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Create a New Metadata Type

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Marten edited this page Apr 28, 2022 · 6 revisions

Now that you understand the high-level concepts of GXE, you can start creating a metadata profile! This page will walk you through the main steps:

Choose a base type

GXE includes several metadata 'types' that can form the basis of your custom editor. These types represent different existing metadata standards and profiles derived from those standards, including:

  • arcgis - This type represents the ArcGIS XML encoding of metadata as used in ArcGIS Desktop (ArcMap + Pro), ArcGIS Enterprise Portal, and ArcGIS Online. If you want seamless exchange of metadata between those products and the Geoportal Server Catalog, use this type as a basis.
  • fgdc - The Federal Geographic Data Committee (FGDC) Content Standard for Digital Geographic Metadata (CSDGM) is one of the longest used metadata standards in the geospatial industry. Many organizations around the world still rely on the FGDC metadata standard. Over time there have been several organizational or thematic profiles created of the FGDC standard.
  • gemini - Gemini is a metadata profile of ISO 19115/19119/19139 and is managed by the Association for Geographic Information of the United Kingdom.
  • inspire - INSPIRE is the metadata type used across the European Union in support of the INSPIRE Spatial Data Infrastructure. INSPIRE metadata is a profile of ISO 19115/19119/19139 metadata.
  • iso - ISO represents a family of metadata specifications designed by International Organization for Standardization (ISO) Technical Committee 211 (ISO/TC 211) and includes content standards such as ISO 19110, ISO 19115, ISO 19119, ISO 19115-1/19115-2 and XML encoding standards such as ISO 19139 and ISO 19115-3. Content standards and XML encoding standards are to be used in specific combinations (19115 + 19139, 19115-1 + 19115-3, etc). INSPIRE

Define the new type

Once you have chosen the base profile, you need to define the new type. this is done in metadata-editor.js

Every allowable type has a unique identifier, defined in metadata-editor.js. For every enabled type, a typeDefinition is given, for example for INSPIRE dataset metadata (type key inspire2-iso-19115):

    {
      key: "inspire2-iso-19115",
      requiredPath: "app/gxe/types/inspire2/base/DataDocumentType",
      interrogationRules: [
        {
          path: "/gmd:MD_Metadata/gmd:identificationInfo/gmd:MD_DataIdentification",
          must: true
        },
        {
          path: "/gmd:MD_Metadata/gmd:metadataStandardName/gco:CharacterString",
          value: "INSPIRE Metadata Implementing Rules"
        },
        {
          path: "/gmd:MD_Metadata/gmd:metadataStandardVersion/gco:CharacterString",
          value: "Technical Guidelines based on EN ISO 19115 and EN ISO 19119 (Version 2.0)"
        }
      ]
    },

where:

  • key = the unique key for this metadata type
  • requiredPath = path to the main editor entry file (*.js). This is the file from which the editor definition starts
  • interrogationRules = list of xpath expression (path) and obligation (must, mustNot) that will be used to match an XML document to this particular metadata type. It is important to understand that Geoportal Server interprets the metadata types in the order in which they are defined in metadata-editor.js in the list gxeContext.allowedTypeKeys. The first matching type is assumed to apply to the XML document.

Apart from the definition of individual types, metadata-editor.js also is where you make some generic GXE settings. For example

  • editable - Editing documents that were harvested into Geoportal Server Catalog may be edited in GXE if they are of one of the defined types and if their type is listed in editable.geoportalTypes. The setting editable.allowNonGxeDocs controls whether only documents created in GXE (in another catalog for example) or also non-GXE documents may be edited. If a document is created in a non-GXE editor, it is not known if there are additions or modifications to the metadata standard/profile that were implemented in that other editor. Then editing such a document in GXE may result in loss of information if those additions or modifications were not also implemented in GXE.
  • gxeContext.basemap - set the basemap for the map used in GXE to one of the named ArcGIS Online basemaps
  • gxeContext.allowViewXml - allow the user to view the metadata XML within GXE (true) or not (false)
  • gxeContext.showValidateButton - show the Validate button in the editor (true) or not (false), allowing the user to explicitly validate the metadata while in GXE.
  • gxeContext.validateOnSave - whether (true) or not (false) the metadata when saving metadata in GXE.
  • gxeContext.startupTypeKey - one of the configure metadata type keys to use as default when opening the editor and starting a new document.

Create your root documents

Basics and Folder structure

The starting point of the actual editor is the file identified by the requiredPath setting in the typeDefinitions list for your type defined in metadata-editor.js. This documentation uses the sample profile defined in xx-metadata-editor-example.js. For this type (which is a profile of ISO 19115/19139):

requiredPath: "app/gxe/types/myprofile/base/DataDocumentType"

When starting a new type, it is important to think ahead how to organize the files for the type. While technically all could be in a single folder, it is best practice to group related files together, for example how is done in the ISO types, where each namespace gets its own sub-folder:

image

There are typically 2 folders always present: base and nls. The first is the base of the metadata type, the second holds the localization files for this metadata type.

DocumentType

In the case of the sample profile, the requiredPath points to a JavaScript file DataDocumentType.js. This file defines literally the base of the metadata type, by setting such parameters as:

  • caption: i18nMyProfile.documentTypes.data.caption,
  • description: i18nMyProfile.documentTypes.data.description,
  • key: "myprofile-iso-19115",
  • isService: false,
  • metadataStandardName: "MyProfile",
  • metadataStandardVersion: "1.0"

Value key is mandatory and needs to match the value for key for this type in the list of allowable types mentioned above. Values such metadataStandardName and metadataStandardVersion are optional, but may be useful if you need to reference the name and version across different parts of the editor. The caption and description values use localized strings as per the Dojo internationalization approach (i18n).

Typically (but this depends on the metadata type) you may have a DocumentType for data and services:

When you do, there are certain properties of the type that may be shared between data and service metadata. A good practice is to extract those into a separate dojo class and use the inheritance capabilities to merge common and specific aspects. In the sample type, this does lead to a MyProfileDocumentType class.

DataDocumentType and ServiceDocumentType override the MyProfileDocumentType class!

The common MyProfileDocumentType class includes some of the type attributes (although these will be overridden in the specific data/service document type classes), but also shows some behavioral capabilities of GXE.

Declaring XML Namespaces

Metadata standards such as those from ISO typically use XML Namespaces to unambiguously define the elements and attributes of the XML content. If your metadata type has namespaces, you can declare them in the ...DocumentType classes. To do this, call this.addNamespace(<prefix>, <namespaceurl>) inside the function initializeNamespaces() as follows. The function initializeNamespaces will automatically be invoked for the metadata type.

    initializeNamespaces: function() {
      this.addNamespace("cat", "http://standards.iso.org/iso/19115/-3/cat/1.0");
      this.addNamespace("cit", "http://standards.iso.org/iso/19115/-3/cit/2.0");
      this.addNamespace("gcx", "http://standards.iso.org/iso/19115/-3/gcx/1.0");
      ...
    }

See the ISO 19115-3 DataDocumentType class for a comprehensive list of namespaces as used in ISO 19115-1/19115-3 metadata.

Updating Type Element and Attribute Behavior

You can set behavior and default of the editor elements and attributes in the DocumentType classes through these functions:

  • beforeInitializeAttribute: function(gxeDocument, attribute)
  • beforeInitializeElement: function(gxeDocument, element)
  • afterInitializeAttribute: function(gxeDocument, element)
  • afterInitializeElement: function(gxeDocument, element)

Within these typical actions may include:

  • changing the optionality of an element:
    • element.minOccurs sets the minimum number of elements that need to be present: 0 means the element is optional, 1 means the element is mandatory
    • element.maxOccurs sets the upper limit: 1 means at most 1 element may be entered, 'unbounded' means the element may repeat many times
  • changing the choices for an attribute:
    • attribute.optionsFilter sets the values in the options for an attribute

many of the settings will work on a specific element or attribute via its gxePath. This value is an xpath expression to the element or attribute you are trying to modify, for example:

var p = element.gxePath;
if (p === "/gmd:MD_Metadata/gmd:contact/gmd:CI_ResponsibleParty/gmd:contactInfo/gmd:CI_Contact/gmd:address/gmd:CI_Address/gmd:electronicMailAddress") {...}
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