Search DrupalHybrid.com

INTEGRATION OF SOCIAL AND SEMANTIC WEB FEATURES IN CONTENT MANAGEMENT SYSTEM: ISLANDORA ..continue...


4.5 Creating Fedora Collections in Drupal using Islandora
To add a collection to a repository, the user needs to go to the “Add” tab and it will offer options of different content modules. By default the installed content module is a collection; this is also a parent class for all other collection content modules. In the Figure 4.7 WSSU main page is a name of the collection I have added to the repository. An added collection can have a thumbnail. So, I have cropped the full size image to a thumb size image and added it as a datastream under the name TN. After adding the TN datastream, I got the thumbnail of the WSSU main page repository displayed in       Figure 4.7.

Figure 4.7. Adding a collection to a repository
The Islandora demo collection comes with a collection of some popular collections like image and pdf. This provides an option for users to add collections of various available types without creating their own collection content types. Here I have created a collection of type “image” with a name of Photography and have included a thumbnail datastream from the Object detail option.
Figure 4.8. Adding an Image collection to the Islandora Demo Collection

Figure 4.9.  Default datastreams
Adding an image to a collection is easy. Any number of images can be added by going to the “Add” tab. This will give an option to upload and give metadata about the image like title, description, date, etc. But the default view of a collection of images did not have thumbnail view of images in the collection like in the Figure 4.10.
Figure 4.10. Collection with no thumbnails
I found out that this can be solved by adding the ImageAPI module to the Drupal installation. This module does not provide any functionality to Drupal; it is only used by the Fedora repository. This module converts every image in a collection into a small size image and shows it as a thumbnail for the high pixel image.
Figure 4.11.  Configuring ImageAPI module
After configuring the ImageAPI module, a thumbnail view was shown for every added image.
Figure 4.12. Before and after the installation of ImageAPI
The ImageAPI module only works when the collection has related datastreams ingested to it. In addition to the RDF Statements and Dublin Core Record datastreams, I have added ‘Thumbnail’, ‘Collection view’ and ‘Collection policy’ datastreams to the object (Demo:42). I downloaded these streams from the Smiley demo collection, which is included in the Islandora distribution (it is in the ‘Detailed list of contents’ screen of the opened collection).  Figure 4.13 shows all datastreams for the object “Image Collection” including the three newly added datastreams. In the Figure 4.12, the first three images have been added before the installation of the ImageAPI module and the next two after its installation and adding the corresponding datastreams.
Figure 4.13.  Added Thumbnail, Collection view and Collection policy datastreams
We can also view the created (in the Drupal interface) objects with their datastreams and relationships directly in the Fedora GUI. In the next section, we inspect an object of the created Image Demo Collection – the object with an identifier (PID) Demo: 42.
4.5.1 Viewing objects in Fedora GUI
In order to get an access to the Fedora repository, a user has to have administrative privileges. The user can login as a Fedora Administrator by using the password provided during the Fedora installation.
Figure 4.14.  Fedora Login Page
To view a digital object in the Fedora interface, the user has to provide the PID for that object. A PID is a unique, persistent identifier for a Fedora digital object. 
Figure 4.15.  Fedora PID dialogbox
In the Figure 4.16 a digital object with PID demo: 42 is opened and Fedora gives a detailed list of the metadata about this object. The “active” state means that this object is in a running mode and the user can access it by search and view commands.
Figure 4.16. Metadata about a Fedora object
The Figure 4.17 shows the interface after clicking on the Datastream tab, which gives a list of all the datastreams associated with the object. This object is an Image object and it can be viewed in three different sizes (Full size, Medium size and Thumbnail size).
Figure 4.17. Full size view of image with FULL_SIZE datastream

Figure 4.18. Thumbnail size view of image with TN datastream
The user can also modify digital objects from the Fedora interface. All changes will be reflected in the Drupal interface. The Figure 4.19 shows a RELS-EXT  datastream of an Image object. This is a default datastream coming with every object and it allows adding relations to the object. This is the main semantic datastream which provides an RDF triple with Subject, Predicate and Object. Here in this Figure 4.19, demo:42 is a Subject and it is a member of the islandora:7 object. 
Figure 4.19. RDF Triple of Digital Object

DC datastream is a Dublin Core Datastream. Dublin Core is an ontology, which includes basic metadata describing an object, such as title, description, date, subject, etc.
Figure 4.20. Dublin Core Datastream
All changes (additions, deletions, and updates of objects) made through either the Fedora GUI or the Drupal interface are performed on the Fedora repository that is the common backend of both, and so are reflected in both interfaces.
4.5.2 Creating Content Model
The Islandora Content Modeller module is not included in the Islandora repository, but it can be installed separately from the Drupal site. This tool is useful in creating and managing datastreams. Once installed and configured, the user can access it from the Drupal’s Content Management menu. At opening, it will give the user a view of the installed collections as a tree on the left hand side of the screen; on the right hand side are the installed content models.
Figure 4.21. Islandora Content Modeller
Creating content models using the content modeller module should be easy, but as with the Islandora repository, this module is also in an initial phase of development. I have tried it many times: sometimes it works, and sometimes it does not work. The ‘Plus’ icons at the right corner of the allowed content models give user the ability to create new content models. The user can also create content model from a Child Collection’s ‘Plus’ icon as shown in the Figure 4.22.
Figure 4.22. Creating a content model
By clicking on the Plus icon of the Child Collection, the user will get an option to enter the PID, Name, and Initialized Collection Policy.  The Initialized Collection Policy will further give options such as to copy the content model from a previously created content model. Here I have created a content model for bookmarks with PID as “bkmark:cm”.
Figure 4.23. Creating a Content Model
To define a namespace for PIDs, it is required to add the name of the namespace in the ‘allowed namespace fields’ in Islandora configuration (see the Figure 4.24 with the added namespace “bkmark:”).
Figure 4.24. PID must be present in the ‘PID namespace allowed’ field.
After passing this phase, the user can define relationships with other collection members, a namespace, fields and labels. For example, a relationship for the Bookmark content model is that it is a member of the default collection. 
Figure 4.25. Creating a content model
After saving a content model, the user can navigate to the Digital repository to add a collection that belongs to the created content model. The interface will show all the installed content models in the list. The Figure 4.26 shows the Bookmark content model in the list.
Figure 4.26. Adding the created content model
4.5.3 XML Form builder
XML Form builder is an Islandora module which provides way for users to create, edit, and copy forms. Required by this module are the modules listed below:
·         Objective Forms
·         Islandora XML Form API
·         Islandora XML Schema API
·         Islandora XML Form Elements
·         Islandora XML Form Builder
·         Islandora XML Forms
·         Islandora Content Model Forms
These modules can be downloaded from the Islandora site and should be installed and configured correctly in order to activate the Form builder module.
XML Form builder has compatibility issues with the Windows operating system. I installed and configured it many times but it did not work. After having conversations on the Islandora mailing list and with input from the people involved in development of Islandora, I found out that for the Windows operating system I need to change the name of the “ext-4.0.2a” folder located in builder/lib to “ext”; Windows does not do symlinks, so renaming “ext-4.0.2a” to “ext” worked. The Form builder comes with a GUI, which helps users to add, delete, and manipulate form elements.
Figure 4.27.  XML Form builder

Once installed and configured, users can open the XML Form builder from Drupal’s content management menu. Users can import and export forms from this module. Figure 4.28 below shows a display view of the Form builder. It comes with a default form, which includes basic features of the Dublin Core ontology, such as Title, Creator, Description, etc. Users can use the View button to view the contents of the default form.
A user can also copy the default form and change its name as they wish. Figure 4.29 shows copying the default form and changing its name to ‘bookmark_copied’. By inspecting the new form with the View button, we can see that it contains the same form elements as the default form (Figure 4.28).
Figure 4.28. View option of the XML Form builder


Figure 4.29. Copy option of the XML Form builder
Once the default form is copied to another form, users can edit the copied form - clicking the Edit button of the Form builder brings the Edit Form screen as shown in Figure 4.30. The options on the left hand side panel allow users to manipulate the presented form. Users can add, copy, paste and delete elements to get the desired form. 
Figure 4.30. Edit property of the XML Form builder
 
After editing and saving the form, the user should link it to the content model they want to associate it with. To do that they have to go to the Administrator menu and then follow the Form Association link. This will bring the options shown in Figure 4.31.
Figure 4.31. Form association module


1 comment:

Anonymous said...
This comment has been removed by a blog administrator.