Linking Items

By Sandra Schloen, December 2014

OCHRE's item-based data model gives ultimate flexibility by allowing virtually any item to link to any other item. Note that although OCHRE allows this it won't always make sense, so it is up to the user to make useful links. Once again, OCHRE uses the same technique to link items of all category types; this makes it is easy to learn how to link all types of data.

You First

You will start this time by inserting some new Resources (images) to be linked to our sample Locations & objects.

  • Select the Resources category and click the insert-below button. (See Inserting and Deleting Items if you need to review this process.) Note that you have a few options. Almost always you will want first to create a hierarchy for items, and then to add new items to that new hierarchy. Go ahead and choose to insert a hierarchy. Call it "My images" or the like (substitute your name, for example, if "My images" already exists).

Insert new hierarchy

With "My images" (or whatever you called it) still selected, insert another new item using the insert-below button. This time choose to insert a new external resource. This item will be used to refer to an image that does not exist in the database itself but which is accessed via a URL. We have several sample images set up on our server for you to use.

  • Aleppo_church.jpg (church in the Christian quarter of Aleppo)

  • Damascus_mosque.jpg (Umayyad mosque in Damascus)

  • Damascus_suq.jpg (Damascus suq by night)

Pick one of the images listed above to be referenced by this new OCHRE resource.

  • Give the new OCHRE resource an appropriate Name and Description.

  • Set the item Type to image.

  • Enter the file name in the File URI field of the new resource's edit pane.

  • Refresh the image (to review how to do this see Inserting and Deleting Items). Notice that OCHRE auto-fills the final URL(s) by pre-pending server information that has been preset as a Project Preference.

List of image types

  • The image is now ready to View. Feel free to try the various "fit" options on the image toolbar, or to request the high-resolution version of the image (which will replace the thumbnail being shown) by clicking the image button on the toolbar.

Image resource

  • Click the information button on the image toolbar (that is, the blue encircled i). This will display the file metadata for this image, reading it directly from the image file. Within the list of metadata, find the original date on which this photo was taken. Return to the Resource tab to enter the photo's date in the edit pane. We will return below to credit the photographer.

The Linked Items Pane

The Linked Items pane is the source of all items being linked and is made visible as the right-hand pane by clicking the paperclip-button near the end of the OCHRE toolbar. From the Linked Items pane you can pick the Project from which to find the target of the link. In this tutorial project, only items from the OCHRE Tutorial are available for linking. Once a project is selected you must then select the Category of item you wish to use as the target of a link. The full item list for the selected Category is presented in the lower part of the Linked Items pane. Navigate through this list to the item to be used for the link.

In this example we are linking the Person (photographer) Miller Prosser as the Creator of the image. With the image selected in the navigation pane and the person selected from the Linked Items pane, all that remains is to perform the link by clicking the Add link (paperclip+) button.

Link an Image to a Location or Object

Your Turn

  • First of all, go ahead and credit the photographer by linking him in as the Creator of the image as described above.

  • Now, here's a shortcut. Find the "Go to ..." button in the Linked Items pane (the arrow-with-question-mark). Since the currently selected item in the navigation pane is our new resource item, the Go to button will navigate automatically to that same item, but in the Linked Items pane. Try it.

  • Next, in the navigation pane, navigate to the item of interest in the Locations & objects category (Middle East, Syria, Aleppo or Damascus as appropriate to the image chosen).

  • Create a new item within the Aleppo or Damascus parent item to represent the church, mosque, etc., as appropriate for your chosen image, and give it a Name and Description (to review how to do this see Inserting and Deleting Items).

  • Select the Links tab of the edit pane of the current observation of the new item. From the Other links toolbar, use the Add item link (paperclip+) button to make the link.

  • To finish up, View the item to see the link relationship.

Linking Items

Congratulations! You now know how to create and organize items of all kinds in OCHRE and how to link them to each other in useful ways.