Adding hyperlinks to PDF documents with AutoBookmark™ plug-in
Introduction
The AutoBookmark™ plug-in for Adobe® Acrobat® provides multiple ways of automatic generation of hyperlinks in PDF documents. One of the most basic methods is a "link dictionary" approach. It is designed to add links to a predefined set of words and phrases. A link dictionary is a collection of search terms (words, phrases) and corresponding actions (such as "Go to a page view" or "Open a web page"). The software searches a PDF document for occurrences of specific search terms and generates links according to user specifications. Link dictionaries can be created manually using a supplied editor, imported from an ASCII text file or generated from bookmarks.
What is PDF link?
PDF format supports link annotations, also known as simply links or hyperlinks. Link is a rectangular area located anywhere on the page. Each link has a corresponding PDF action associated with it. This action is executed when user clicks anywhere in the link area. Examples of actions: go to a page view, open a file, open a web link, open an attachment and etc.
Supported Action Types
The AutoBookmark™ allows adding PDF links with the following actions:
  • Go to a specific page number in the same PDF document
  • Go to a named destination in the same PDF document
  • Go to a specific page number in another PDF document
  • Go to a named destination in another PDF document
  • Open a web page
  • Open another file or document
  • Go to a page in attachment
  • Execute a menu item
Step 1 - Opening PDF Document
Start Adobe Acrobat and open a PDF file you want to process. Select "Plug-ins > Links > Create Links From Dictionary..." from the main menu. This will open "Create Links From Dictionary" dialog. Press "Create New Dictionary" button to open a link editor. If you already have a previously created dictionary, then press "Browse..." button to load it.
Step 2 - Editing Link Dictionary
Link dictionary is a collection of search text items and corresponding actions. Press "Add..." button to add a new search term to the dictionary. The AutoBookmark will use these descriptions to search PDF documents for these search terms and add corresponding hyperlinks.
Step 3.1 - Linking to a page view (example)
Pressing "Add..." button in "Edit Link Dictionary" dialog opens "Edit Link Action" screen. Type a text to search for into "Text to add link to" box. In the example below, it is "Adipine". Next, select a desired "Action type" using corresponding pull down menu (select "Go to a page view" if it is necessary to display a page inside the same document). Enter a destination page number or specify a named destination to display. Press OK button to save this search item into the dictionary.
Step 3.2 - Linking to a page in another PDF document (example)
Pressing "Add..." button in "Edit Link Dictionary" dialog opens "Edit Link Action" screen. Type a text to search for into "Text to add link to" box. In the example below, it is "Adipine". Next, select a desired "Action type" using corresponding pull down menu (select "Go to a page in another document" if it is necessary to display a page in another PDF document). Enter a destination page number or specify a named destination to display. Type a filename (relative file path) into "Document name" box. If a destination file is located in the same folder, then enter just a filename. If it it necessary to link to a file located in a sub-folder, then type SubFolderName/FileName.pdf.
Press OK button to save this search item into the dictionary.
Step 3.3 - Linking to a web page (example)
Pressing "Add..." button in "Edit Link Dictionary" dialog opens "Edit Link Action" screen. Type a text to search for into "Text to add link to" box. In the example below, it is "Adipine". Next, select a desired "Action type" using corresponding pull down menu (select "Open a web page" if it is necessary to display a web page). Type web page address into "URL" box and select required protocol from the pulldown menu. Leave it as "http://" if you just want to add a regular web link. Press OK button to save this search item into the dictionary.
Step 4 - Building Link Dictionary
Repeat step 3 multiple times - once for every search term. The screenshot below shows a link dictionary that contains multiple search terms with "Open a web page" action.
Alternatively, it is possible to use any spreadsheet application (such as Microsoft Excel) to create a link dictionary and then import it into the application (use "Import From Text" button). 
The most effective method for automatic generation of a link dictionary is from existing bookmarks. Press "From Bookmarks..." button to add existing bookmarks as link dictionary entries. Bookmark titles are added as search terms and bookmark actions are used as corresponding link actions.
Press OK button once the link dictionary is complete. If this is a new dictionary, then you would be prompted to save it to disk.
Step 5 - Specifying Link Appearance
Press "Edit Appearance..." button to define a visual appearance of hyperlinks. This style will be applied to all hyperlinks created with this link dictionary.
Use "Edit Link Appearance" dialog to configure visual appearance:
The software allows changing the color of underlying text elements. Please note that in PDF format, text and links are two separate and unrelated entities. Deleting the links will not change the color of the text back.
Press OK button once done to close this dialog.
Step 6 - Selecting Processing Page Range (Optional)
Press "Edit Page Range..." button to select a range of pages where to add links.
Use "Select Page Range" dialog to specify a page range either directly by providing page numbers or indirectly via bookmarks, named destinations, or page labels. Indirect page referencing provides a powerful mechanism for customized document processing.
PressOK button once done selecting a page range.
Step 7 - Selecting Processing Page Area (Optional)
Sometimes it is necessary to limit processing only to a specific area on the page. Press "Edit Page Area..." button to specify processing area.
Use "Processing Area" dialog to enter coordinates of the processing area:
PressOK button once done selecting a processing area.
Step 8 - Generating Links
Press OK button to start generating links for the current document. All settings are automatically saved as part of the link dictionary. Use "Browse..." button to load a previosly saved dictionary.
Important: if a part of the text is already covered by an existing link, then a new link is not added to this area. Use "Plug-ins > Links > Delete Links" menu to delete links prior to processing if necessary.
Step 9 - Inspecting Results
Inspect and test resulting links once processing is completed.
Advanced: Building Links in Multiple PDF Documents At Once
Adobe Acrobat Professional comes with a powerful batch processing engine called "Action Wizard". It is also known as "batch processing" in older versions of Adobe Acrobat. AutoBookmark Pro plug-in supports Action Wizard and adds most of its functionality as batch commands. Use the following tutorial to create powerful batch actions. It is possible to process multiple files in multiple folders. Use "Create Links From Dictionary" batch command to generate links in multiple documents. Batch commands are configured visually, by using identical procedure to the one described in this tutorial. There is no programming or scripting involved.