v5.0
SetGlobal and its companion command GetGlobal
provide a simple means to store and retrieve values
which act like "global variables". Each variable is indentified
by a unique string. To change the value of a previously
set variable call this command with a new value. To erase
a global variable call this command with null as the value.
These variables are accessible from any script and remain
active during the duration of the Softimage session.
Warning: For persistent Global values it is better to use a
CustomProperty or a Custom Preferences object.
Tip 1: It is possible to store a Softimage object inside a global
variable. However when storing a reference to a Softimage object,
it is often safer to store the fullname string of the object rather
than the object itself. This ensures that even if the scene is closed,
reopened or significantly changed you can get a valid reference
to the object (as long as the object isn't renamed). This is
demonstrated in the examples below.
Tip 2: This command will convert any JScript Array or
user-created script object into a SAFEARRAY (see Array).
To maintain the data in its original form use SetGlobalObject.
Tip 3: It is unnecessary to use this functionality if the entire plug-in
is implemented inside a single script, because any variable within
the global scope is accessible inside all functions. (The only exception
is PPGLayout logic callbacks, which cannot read
the values of global variables set by non-PPGLayout callbacks.)
Tip 4: Global variables can be very useful, but usage should be kept
to a minimum to avoid unexpected side-effects, "spagetti" code
and code that is difficult to read, debug and maintain.
Each global variable name should be well chosen to avoid
potential conflict with other scripts. For example if two plug-ins
both try to use a global variable named "x" then both will be
prone to random or unexpected failure.
Tip 5: This feature is implemented as a self-installed
JScript Plugin using the powerful
"Scripting.Dictionary" object which is available to both
VBScript and JScript. For more details refer to the
actual implementation code (GlobalVarPlugin.js).
SetGlobal( in_VariableName, in_Value ); |
Parameter | Type | Description |
---|---|---|
in_VariableName | String | The name of the global variable |
in_Value | Variant | A new value for the global variable |
// Example test for GetGlobal/SetGlobal NewScene( null, false ) ; // null returned when Global hasn't been set ASSERT( null == GetGlobal( "X" ) ) ; SetGlobal( "X", 67 ) ; ASSERT( 67 == GetGlobal( "X" ) ) ; // You can change the value of the global SetGlobal( "X", "foo" ) ; ASSERT( "foo" == GetGlobal( "X" ) ) ; // Remove the global SetGlobal( "X", null ) ; // Handle Softimage Object var oGrid = ActiveSceneRoot.AddGeometry( "Grid", "MeshSurface", "mygrid" ); // You could store a Softimage object as a Global SetGlobal( "InterestingObj", oGrid ) ; ASSERT( oGrid.Name == GetGlobal( "InterestingObj" ).Name ) ; // But it is better to store the string fullname // because oGrid won't survive saving and reloading the scene, SetGlobal( "InterestingObj", oGrid.FullName ) ; // Simulate the user closing and reopening the scene var strTestScene = Application.InstallationPath( siProjectPath ) + "\\Scenes\\Test.Scn" ; SaveSceneAs( strTestScene ) ; OpenScene( strTestScene, false ) ; var strGrid = GetGlobal( "InterestingObj" ) ; // Turn the string back into an object var oGridRevived = Dictionary.GetObject( strGrid ) ; ASSERT( oGridRevived.Name == "mygrid" ) ; // Demonstrate that it really is a valid reference to the grid oGridRevived.posx = 4 ; LogMessage( "Test complete" ) ; function ASSERT(in_val) { if ( !in_val ) throw new Error( 0, "test failed" ); } |
' Example test for GetGlobal/SetGlobal NewScene ,false ' null returned when Global hasn't been set ASSERT( Null = GetGlobal( "X" ) ) SetGlobal "X", 67 ASSERT( 67 = GetGlobal( "X" ) ) ' You can change the value of the global SetGlobal "X", "foo" ASSERT( "foo" = GetGlobal( "X" ) ) ' Remove the global SetGlobal "X", Null ' Handle Softimage Object set oGrid = ActiveSceneRoot.AddGeometry( "Grid", "MeshSurface", "mygrid" ) ' You could store a Softimage object as a Global SetGlobal "InterestingObj", oGrid ASSERT( oGrid.Name = GetGlobal( "InterestingObj" ).Name ) ' But it is better to store the string fullname ' because oGrid won't survive saving and reloading the scene, SetGlobal "InterestingObj", oGrid.FullName ' Simulate the user closing and reopening the scene strTestScene = Application.InstallationPath( siProjectPath ) & "\Scenes\Test.Scn" SaveSceneAs strTestScene OpenScene strTestScene, false strGrid = GetGlobal( "InterestingObj" ) ' Turn the string back into an object set oGridRevived = Dictionary.GetObject( strGrid ) ASSERT( oGridRevived.Name = "mygrid" ) ' Demonstrate that it really is a valid reference to the grid oGridRevived.posx = 4 LogMessage "Test complete" sub ASSERT( in_test ) if NOT in_test then LogMessage "Test Failed", siError end if end sub |