Application actions

To give the users of your applications the possibility to performs actions on it, you must do two things:

• define an action, and
• create an element that will trigger this action.

This means that every application action consists of two components – a trigger and an action proper:

Lycia supports two types of application actions:

• Predefined actions are application actions shipped with Lycia and available by default. 4gl developer doesn't need to specifically define these actions and create their triggers.
• User-defined actions are application actions created by the 4gl developer and defined in the source files of the application. The correct look and feel of the user-defined action is the responsibility of the 4gl developer only.

User-defined application actions

Lycia provides two ways to define an action and 6 ways to create a trigger.

Defining actions

All not-predefined actions are defined by the clauses COMMAND, ON ACTION, and ON KEY.

ON ACTION and COMMAND clauses are available for these statements:

• CONSTRUCT
• DIALOG
• DISPLAY ARRAY
• INPUT
• INPUT ARRAY
• MENU
• PROMPT
  

For example,

ON KEY clauses are available for these statements:

• CONSTRUCT
• DIALOG
• DISPLAY ARRAY
• INPUT
• INPUT ARRAY
• PROMPT
  

Creating triggers

To create a trigger for the action, you can use these ways:

1. Do nothing besides defining it – if the action is not associated with any trigger, Lycia will create it automatically in the form of a toolbar button.
2. Use widgets provided by Lycia Form Designer (usually, ToolbarButton, MenuCommand, and Button though other variants are possible as well).
3. Create ui elements of the ui.<Widget> data type (usually, ui.ToolbarButton, ui.MenuCommand, and ui.Button).
4. Add an element action in SystemActionDefaults.fm2.
5. Add an element action in a master or user action defaults file.
6. Add an element action to the .fm2 form.

You can learn details about these ways here.

Attributes of the application actions

Every action has a set of attributes which determine the appearance and behavior of the application action.

These attributes are

• identifier (mandatory)
• accelerators
• comment
• default view
• action image
• order
• place
• show in context menu
• statical
• text
• validate

You can learn details about the attributes of the application action here.

Modifying the attributes

There are 7 ways to set and modify the action's attributes:

• in Lycia Form Designer
• in Lycia Theme Designer
• via ui methods
• via toolbar functions – fgl_setactionlabel(), fgl_setkeylabel(), fgl_dialog_setactionlabel(), and fgl_dialog_setkeylabel()
• via predefined and user-defined classes
• in SystemActionDefaults.fm2
• in master/user action defaults files (.ad2)

These are all possible ways to modify the attributes of the application action.

However, not every way can be used to modify the attributes of all the application actions – they depend on the trigger.

You can learn details about how to modify the attributes of the application action here.