Amiga Developer CD 2.1/Amiga Developer CD v2.1.iso/Reference/Amiga_Mail_Vol2/Archives/Plain/jf93/ASCII/AmigaGuide/AmigaGuide.txt

Text File | 1993-03-01 | 24.4 KB | 621 lines

(c) Copyright 1993 Commodore-Amiga, Inc.   All rights reserved.
The information contained herein is subject to change without notice,
and is provided "as is" without warranty of any kind, either expressed
or implied.  The entire risk as to the use of this information is
assumed by the user.


AmigaGuideTM 101


by Jerry Hartzler



NOTE: AmigaGuideTM is now available to developers on the 3.0
Workbench release, the CATS Developer CD and Commodore's closed Amiga
developer listings area on BIX, CIX and ADSP.  Developers with a
Workbench or Includes License can amend their license to distribute
AmigaGuide.  Currently CATS is in the process of putting together an
archive file that will be made available to the general public.


Compared to other platforms, Amiga-based utilities that display
on-line documentation are relatively weak.  Until 1991, Amiga users
had to rely on basic text viewing utilities like More, which lack the
navigational capabilities of hypertext programs.  In a hypertext
environment, when the user wants more information on a subject, the
user simply clicks on a word and the hypertext utility automatically
cross references the subject.  No type of hypertext-like utility was
available on the Amiga--that is, until AmigaGuide came along.

AmigaGuide can display plain ASCII text files and AmigaGuide
databases.  An AmigaGuide database is a single file that consists of
a set of documents called nodes.  If you were to convert a book into
an AmigaGuide database, a convenient way to organize the database is
to make each chapter of the book into a node.  Each node may contain
references to other nodes (chapters) or databases (other books),
using a link.  When a user selects a link--which usually appears in
the form of a button within the text--AmigaGuide dereferences the
link and displays its node.  This makes it easier for the user to
find the information he is looking for because the user no longer
needs to search through a document.  AmigaGuide already knows where
the information is.

Buttons within AmigaGuide can do other actions as well, such as
execute Shell or ARexx commands.  An ARexx port is also built into
AmigaGuide providing users the means to support and control the
utility.  Therefore, like a book, an AmigaGuide database can display
illustrations.  It can go a step beyond by playing sounds and music,
and by being truly interactive with the user, able to ask questions
and evaluate responses.

This article was written to familiarize you with AmigaGuide and the
format of its databases.



Setting up AmigaGuide

AmigaGuide consists of the AmigaGuide utility and an Exec library
called amigaguide.library.  AmigaGuide should be placed in the
SYS:Utilities drawer and amigaguide.library placed in the Libs:
drawer.  As of Release 3, the OS comes with a utility called
MultiView that understands and displays AmigaGuide databases.
MultiView requires amigaguide.datatype and .datatypes.library in
order to display AmigaGuide databases.

AmigaGuide can run from the Workbench or the Shell.  To run from
Workbench, the default tool of an AmigaGuide database or text icon
should be set to ``AmigaGuide''.

From the Shell, use the following command template:

    AmigaGuide <my_DataBase>

where <my_DataBase> is the name of the AmigaGuide database or text
file to display.

For example:

    1> AmigaGuide Autodocs

attempts to open the ``Autodocs'' database.  In its search for a
database, AmigaGuide will first look in the current directory and
then through the AmigaGuide path for the database.

The AmigaGuide path is a global environment variable.  AmigaGuide
stores its environment variables in the ENV:AmigaGuide directory
assigned in RAM:.

The variable named ``path'' contains the list of directory names that
AmigaGuide will search through when it attempts to open a database.
Directory names are separated by a space.  The path variable is set
and stored in the ENV:AmigaGuide directory through the use of the
AmigaDOS SetEnv command (Note that as of Release 3, if the AmigaGuide
directory does not exist, SetEnv will not create it).

For example:

    1> SetEnv AmigaGuide/Path "Workbench:Autodocs Workbench:Includes"

Of course all variables set in RAM: disappear once the computer is
turned off.  To prevent this, copy the file ENV:AmigaGuide/Path to
the ENVARC:AmigaGuide directory.  The system copies the ENVARC:
directory to ENV: upon start-up.

The MultiView utility uses the  amigaguide.datatype which uses this
the environment variable as its path.


The AmigaGuide Window

AmigaGuide displays text within an Intuition window.  The window
contains scroll bars, buttons and pull-down menus making it easy to
browse, search and print text.

Along the top edge of the AmigaGuide window is a row of six
navigation buttons:

  Contents: This button displays the Table Of Contents for the current
  database or node.  See the @NODE and @TOC commands below.

  Index: This button displays the Index for the current database.  See
  the @INDEX command below.

  Help: By deafault, this button displays the database named help.guide
  in the s: directory.  Under 3.0, the database is named
  amigaguide.guide in the Help:<country>/sys directory.  This database
  contains help in using AmigaGuide.

  Retrace: This button goes back to the previous node.

  Browse: These buttons step through the nodes in sequential order (the
  order they appear in the database).


AmigaGuide Databases

Creating an AmigaGuide database is quite simple.  An AmigaGuide
database is basically an ASCII text file, embedded with commands to
tell AmigaGuide what to do.  Let's take a look at the commands used
in AmigaGuide and then make up a simple database.

There are three types of AmigaGuide commands.  Database commands
break up a document into nodes.  Node commands set attributes within
a node.  Action commands are only found within a special node command
called a ``link point''.  As the name implies, action commands
perform some action.


Database Commands

Database commands should not be used within the nodes themselves.
They must start in the first column of a line.  If a line in an
AmigaGuide database begins with an at (@) sign, then AmigaGuide
interprets the line as a command.  Although the AmigaGuide commands
appear here in upper-case, AmigaGuide commands are not case sensitive.

@DATABASE <name> - This command identifies a file as an AmigaGuide
database.  It must be the first line of the database.

@NODE <name> <title> - This command indicates the start of a node.
The first node of a database should be named ``MAIN''.  ``MAIN'' is
typically the master table of contents for the database (see the @TOC
node command in the next section).  When AmigaGuide displays the
node, it displays <title> in the window's title bar.  If there are
any spaces in the <title>, it must be in quotes.  A node name cannot
contain spaces, tabs, colons (':') or slants ('/').

@DNODE <name> - This command indicates the start of a dynamic node.
Dynamic nodes are beyond the scope of this introductory article and
therefore are not discussed here.

@INDEX <node name> - This command tells AmigaGuide which node to use
as the index for the database.  When the user hits the ``Index''
button at the top of the AmigaGuide window, AmigaGuide will display
the node specified by this command.  The node can be in another
database.  If the node is in another database, the node name is the
file name of the database followed by a slant (`/`), followed by the
name of the node in the other database.  For example, to access the
MAIN node in another database called ``other_database'', the link
point looks like this:

    @{"my label" LINK other_database/MAIN}

The name of the other database can contain a full path to the other
database.  If it doesn't, AmigaGuide will search the AmigaGuide path
for the other database.

@REMARK <remark> - This commands lets you add programmer remarks to a
database.  AmigaGuide ignores the remarks.


Node Commands

These commands are only valid within a @NODE.  They must start in the
first column of a line unless otherwise noted.

@ENDNODE <name> - This command ends a node.

@TITLE <title> - AmigaGuide displays <title> in the node's window
title bar.  It must start at the beginning of a line.  This command
isn't necessary if you use the <title> option in @NODE.

@TOC <node name> - This command tells AmigaGuide which node to
display when the user hits the ``Contents'' button while displaying
this node.  If a node does not have a @TOC command, the table of
contents defaults to ``MAIN''.  The <node name> can be in another
database.  See the @INDEX command in the ``Database Commands''
section for more information on the format of <node name>.

@PREV <node name> - The ``Browse'' buttons can be reprogrammed so as
not to step through the nodes in sequential order.  For example, if
this command appears in a @NODE, AmigaGuide  will display the <node
name> node when the user selects the ``< Browse'' button while in the
current node.  The <node name> can be in another database.  See the
@INDEX command in the ``Database Commands'' section for more
information on the format of <node name>.

@NEXT <node name> - Similar to @PREV but will display the <node name>
node when the user selects ``Browse >'' button while in the current
node.  The <node name> can be in another database.  See the @INDEX
command in the ``Database Commands'' section for more information on
the format of <node name>.

@{"<label>" <action command>} - This command is referred to as a link
point.  AmigaGuide makes the string <label> into a button.  The
<label> must be enclosed by quotes.  When the user hits that button,
AmigaGuide carries out <action command> (see the next section of this
article for a description of action commands).  A link point does not
have to start in the first column, it can appear anywhere on a line.


Action Commands

These commands are for use with the link point command described in
the ``Node Commands'' section of this article.

LINK <node name> <line#> - This command loads and displays the <node
name> node at the line number specified in <line #>.  The <line #>
parameter is optional and it defaults to zero.  The node can be in
another database.  The <node name> can be in another database.  See
the @INDEX command in the ``Database Commands'' section for more
information on the format of <node name>.

The <line #> parameter is optional and it defaults to zero.  The
default line number is line zero.

RX <ARexx command> - This commands executes the ARexx macro named in
<ARexx command>.

RXS <command> - This commands executes the ARexx string file named in
<command>.

SYSTEM <command> - This commands executes the AmigaDOS command named
in <command>.

QUIT - When AmigaGuide encounters this command is shuts down the
current database.


A Working Database

As an example, Let's make the text file below into a simple
AmigaGuide database.  The simple database will consists of a single
node.

  What is a user interface? This sweeping phrase covers all
  aspects of communication between the user and the computer. It
  includes the innermost mechanisms of the computer and rises to
  the height of defining a philosophy to guide the interaction
  between human and machine.  Intuition is, above all else, a
  philosophy turned into software.  See the Amiga ROM Kernel
  Reference Manual: Libraries for more information.

  Intuition screens are the basis of any display Intuition can
  make. Screens determine the fundamental characteristics of the
  display such as the resolution and palette and they set up the
  environment for multiple, overlapping windows that makes it
  possible for each application to have its own separate visual
  context.

  Windows are rectangular display areas that open on screens.
  The window acts as a virtual terminal allowing a program to
  interact with the user as if it had the entire display all to
  itself. Windows are moveable and can be positioned anywhere
  within the screen on which they exist.  Windows may also have a
  title and borders containing various gadgets for controlling
  the window.

  Gadgets are software controls symbolized by an image that the
  user can operate with the mouse or keyboard.  They are the
  Amiga's equivalent of buttons, knobs and dials.

  Menus are command and option lists associated with an
  application window that the user can bring into view at any
  time.  These lists provide the user with a simple way to access
  features of the application without having to remember or enter
  complex character-based command strings.

If AmigaGuide displayed the file above, it would appear without any
buttons linking it to text files or databases.  To mark this file as
an AmigaGuide database, add the @DATABASE command.  As mentioned
earlier, it must start on the first line in the first column of the
file.

Since there will be no index for this database, the next command can
be a @NODE.  For AmigaGuide to open a database, it must contain a
node.  Since this will be the first node in the database, it should
be named ``MAIN''.

At the bottom of the file, on a separate line, add the @ENDNODE
command.  This tells AmigaGuide that the current node ends here.  All
nodes must contain an @ENDNODE command.

This is what we have so far:

    @DATABASE
    @NODE MAIN
    What is a user interface? This sweeping phrase covers all
            .
            .
            .
    complex character-based command strings.
    @ENDNODE

The file is now an AmigaGuide database.  However, since the database
has only one node and has no link points, the database will still
appear as plain text.  Also, AmigaGuide will ghost all of the
navigation buttons.  The database can be broken into smaller nodes if
desired.  Normally such a short file would not need to be broken up,
but it makes a good example.

One important issue to consider while designing an AmigaGuide
database is how to lay it out.  Some thought should go into the
break-up of a document into manageable nodes, and how these nodes
relate--and eventually link--to one another.  Each node should
consist of information dealing with one topic and should contain
links to other related nodes.

Notice that the example text is about Intuition, but each paragraph
discusses a different topic of Intuition.  The first paragraph is an
overview followed by four paragraphs: one each on screens, windows,
gadgets and menus.  This organization makes it convenient to make
each paragraph a node with a table of contents in the beginning:


    Intuition Table of Contents

    Introduction
    Screens
    Windows
    Gadgets
    Menus


Since the ``Table of Contents'' node is first, it is the MAIN node.
The other paragraphs follow the MAIN node, each in their own separate
node.  So as not to confuse AmigaGuide, each node within a database
must have a different name.

    @DATABASE
    @NODE MAIN "Intuition Table of Contents"
    Introduction
    Screens
    Windows
    Gadgets
    Menus
    @ENDNODE

    @NODE Intro "Introduction"
    What is a user interface? This sweeping phrase...
    @ENDNODE

    @NODE Screen "Screens"
    Intuition screens are the basis of any display...
    @ENDNODE

    @NODE Window "Windows"
    Windows are rectangular display areas that open...
    @ENDNODE

    @NODE Gadget "Gadgets"
    Gadgets are software controls symbolized by an...
    @ENDNODE

    @NODE Menu "Menus"
    Menus are command and option lists associated...
    @ENDNODE

When AmigaGuide loads the database above, AmigaGuide displays the
MAIN node with the title string ``Intuition Table of Contents'' in
the window's title bar.  As the user clicks the ``Browse'' buttons at
the top of the AmigaGuide window, AmigaGuide steps through each node
in the database, displaying each paragraph.  Notice that each node in
the database uses the window title parameter.  As the ``Browse''
buttons step through the database displaying the different nodes in
sequence, the AmigaGuide window title changes to match the title from
the current node.

An important limitation of the database above is the only way to
access the different nodes is using the ``Browse'' button to step
through them in the order they appear in the database.  The database
still has no buttons within the nodes to link to other nodes.


Using Link Points

The link point command is probably the most commonly used command in
a database.  With it you can make a word in one node reference
another node.  For example, in the ``Table of Contents'' node from
the previous example, you can make each entry from the table into a
button that references its respective node.

The template for a link point is:

    @{<label> <action command>}

The label parameter is the word or phrase in a database that is made
into a button, and the action command is the action AmigaGuide takes
when the user clicks the button.  For our example, we want each topic
in the table of contents to be a label and the action command for
each to be a LINK command.  The LINK command loads and displays
another node.

    @{<label> LINK <name> <line#>}

For example, if you change the word ``Introduction'' from the Table
of Contents node into a link point it would look like this:

    @{"Introduction" LINK Intro}

The <label> string must be in quotes.  If you load the database into
AmigaGuide after making the change above, the word ``Introduction''
would appear as a button on the Table of Contents screen.  If the
user clicks on the ``Introduction'' button, AmigaGuide displays the
node named ``Intro''.

Unlike other AmigaGuide commands, link points do not need to start in
the first column.  This makes it easy to indent a button from the
left edge of the window and also to embed a button within a block of
text.

Link points can also link to nodes in other databases.  As an
example, consider the following excerpt from the ``Intro'' node:

  philosophy turned into software.  See the Amiga ROM Kernel Reference
  Manual: Libraries for more information.

If an AmigaGuide database of Amiga ROM Kernel Reference Manual:
Libraries was readily available,  it would be convenient if the word
``Libraries'' from the excerpt was a button, linking the word
``Libraries'' directly to the Libraries manual database.  If the
Libraries manual database was named Libraries_Manual and it was in
the current AmigaGuide path, to make the word ``Libraries'' from the
``Intro'' node into a link point that opens the Libraries_Manual
database, change the excerpt above to the following:

  philosophy turned into software.  See the Amiga ROM Kernel
  Reference Manual: @{"Libraries" LINK Libraries_Manual/Intro} for more information.

In the example above, when the user selects the ``Libraries'' button,
AmigaGuide will try to display the MAIN node from the database called
Libraries_Manual.  AmigaGuide will first look for Libraries_Manual in
the directory where the example database resides.  If it's not there,
AmigaGuide searches through its path for the database.  Alternately,
you can supply a full path name to Libraries_Manual.

A link point can also be used to display a picture.  For example, to
display an ILBM image of a Workbench screen from the ``Screen'' node,
use the SYSTEM action command:

    @{"Picture of a Workbench Screen" SYSTEM sys:utilities/Display sys:Workbench.pic}

From the command above, when the user click the ``Picture of a
Workbench Screen'' button, SYSTEM executes the Display utility.
Display shows the ILBM file sys:Workbench.pic.  Because Display is
merely a shell command, you can substitute your own ILBM viewer for
Display.

Below is the finished database with a few more interactive link
points.

  @DATABASE
  @NODE MAIN "Intuition Table of Contents"
  @{"Introduction" LINK Intro}
  @{"Screens" LINK Screen}
  @{"Windows" LINK Window}
  @{"Gadgets" LINK Gadget}
  @{"Menus" LINK Menu}
  @ENDNODE

  @NODE Intro "Introduction"
  What is a user interface? This sweeping phrase covers all
  aspects of communication between the user and the computer.  It
  includes the innermost mechanisms of the computer and rises to
  the height of defining a philosophy to guide the interaction
  between human and machine.  Intuition is, above all else, a
  philosophy turned into software.  See the Amiga ROM Kernel
  Reference Manual: @{"Libraries" LINK Libraries_Manual/Intro} for more information.
  @ENDNODE

  @NODE Screen "Screens"
  Intuition screens are the basis of any display Intuition can
  make.  Screens determine the fundamental characteristics of the
  display such as the resolution and palette and they set up the
  environment for multiple, overlapping @{"windows" LINK Window} that makes it
  possible for each application to have its own separate visual
  context.

  @{"Picture of a Workbench Screen" SYSTEM sys:utilities/Display sys:Workbench.pic}

  @ENDNODE

  @NODE Window "Windows"
  Windows are rectangular display areas that open on @{"screens" LINK screen}.  The
  window acts as a virtual terminal allowing a program to interact
  with the user as if it had the entire display all to itself.
  Windows are moveable and can be positioned anywhere within the
  screen on which they exist.  Windows may also have a title and
  borders containing various @{"gadgets" LINK Gadget} for controlling the window.
  @ENDNODE

  @NODE Gadget "Gadgets"
  Gadgets are software controls symbolized by an image that the
  user can operate with the mouse or keyboard.  They are the
  Amiga's equivalent of buttons, knobs and dials.
  @ENDNODE

  @NODE Menu "Menus"
  Menus are command and option lists associated with an
  application @{"window" LINK Window} that the user can bring into view at any
  time.  These lists provide the user with a simple way to access
  features of the application without having to remember or enter
  complex character-based command strings.
  @ENDNODE

Although this is a small sample and only a few basic commands are
used, it is a good start to making your own AmigaGuide database.


The Doctor Is In

To make it easier to create a bug-free database, below is a list of
common mistakes made when editing an AmigaGuide database.

As with any type of programming, errors are bound to crop up.  One of
the most common mistakes is spelling errors.  Always double check
your spelling of commands.  Also, make sure all commands that should
begin in the first column do so.


Symptom:  AmigaGuide displays a database as a text file.  For
example, instead of a button, AmigaGuide displays the link point
command that was supposed to display the button.

Cure: AmigaGuide does not think the file is an AmigaGuide database.
Check that the first line of the file is the @DATABASE command and
that it starts in the first column.


Symptom: When displaying a database node, AmigaGuide displays nothing
in its window.

Cure: Either the @ENDNODE command is not present in the node or the
@ENDCODE command does not start in the first column.


Symptom: AmigaGuide does not display a button or its label.

Cure: The <label> parameter in the link point is missing or not
enclosed in quotes.


Symptom: When the user selects a button, AmigaGuide flashes the
screen and displays the error message ``Couldn't locate <node>''.

Cure: AmigaGuide cannot locate the node specified in the button's
link point command.  If the link point command points to a node in
another database, the database must be in the AmigaGuide path or the
node must contain the full path name to the database.  The link point
command also require a NODE name as the last parameter in the path
separated by a slant (/).  If the file is only text and not an
AmigaGuide database, its path name should end with ``/MAIN''.  If a
node or file has any spaces in its name, the path name must be
enclosed within quotes.


Symptom: AmigaGuide flashes the screen when a button is selected but
displays no error message.

Cure: AmigaGuide does not recognize the <action command> parameter in
the link point, or AmigaGuide cannot locate the specified node (see
the cure above).


Symptom: AmigaGuide does not fully display a button.

Cure: Check that all of the link points end with a closing brace (}).
Note that there is a bug in AmigaGuide that can crash the system if a
link point does not end with a closing brace.


Symptom: AmigaGuide will not load a database and displays a ``Can't
find Node'' requester.

Cure: All databases must contain at least one node.  If the file is
short, all the text can be in one node called ``MAIN''.  If you do
not wish to make the file a database at all, remove the @DATABASE
command.


Symptom: AmigaGuide does not allow the the user to browse the
database to its end.  It either stops browsing before reaching the
last node, or it gets caught in an endless loop, cycling through a
number of nodes.

Cure: At least two nodes within a single database have the same name.
Every node must have a different name unless they are in separate
databases.