Additional Functionality

WASD Hypertext Menu Primer

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4 - Additional Functionality

The features described in this section allow functionality other that merely retrieving and displaying files, and can be easily and effectively employed from the menuing system.

These features largely depend on the underlying BHTS (see 5 - Glossary). For a document on BHTS, see 6 - References).

4.1 - Search Items In Menus

The menuing system provides a simple text-search capability. The search is for plain-text or HTML-text documents (searches on other types are not supported). For an HTML-text file a hit requires the selecting and reading of the entire file, whereas with plain-text a section around the line in which the hit occured can also be selectively extracted.

- NOTE -

Searching is a notoriously CPU and I/O intensive activity. Longer searches progressively decrease scheduling priority by one every 10 seconds, from normal to zero, helping to reduce impact on any interactive users of the server system. The search algorithm itself is efficient, but searching will take longer on a more heavily loaded system because of this mechanism.

A search item is produced by simply appending a question-mark to the file specification. Include no intervening white-space. The description is then included as for any other item, as in the following example:

  *.TXT?   Search all TEXT files in this directory
  LAST_YEAR/*.TXT?   Search last year's files

For GUI browsers (such as Mosaic) this will produce an elegant text entry box into which the search string can be entered, and an [execute] button that may be clicked on (or moved to and activated for text-mode browsers).

The following example illustrates a search item (that is also a live demonstration) that would be created using the following construct:

 MENU_PRIMER_*.HTML?  Search this document for:
Search this document for:

Search Options

Additional characters may be appended after the question-mark providing additional control over the search.

- NOTE -

These may all be selectively applied to a single search by appending the required character(s) to the file specification.

The following example provides a live example, that would be created using the following construct:

 MENU_PRIMER_*.HTML?AOC  Search this document for:
Search this document for:
Case Sensitive: no yes
Output By: line document
About this search.

4.2 - Directory Listings in Menus

A menu can be used to provide a directory listing. The server returns a directory listing whenever a wildcard is present in a specification.

  *.*  The directory this document is in!

The following provides an online demonstration:

4.3 - Full URLs in Menus

In place of a file specification a full URL can be supplied. It must be enclosed by quotation marks. This allows an item within a menu to specify any link acceptable within the Hypertext environment. For example, the WASD Hypertext Teledex could be included in a menu using:

  "http://host/teledex"  WASD/DSTOS Hyper-Teledex

The following provides an online demonstration:


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