lang • use

USE

Since 3.7

USE "Component or Library" [ , "Component or Library" ... ]

Only for Gambas Scripting with gbs3.

Declares that a class or script will use one or several components or libraries.

This declaration must be written in the class or script header.

The components and Libraries are specified by strings. They will be loaded the first time the class or module is used.

Both Component and Libraries may be mixed in the same USE statement.

Example

use "gb.args","vendor.mylib:0.0.1","gb.eval" ....

How Components are referenced

Components are referenced by the complete name as listed under Components

The components are looked for in the Gambas default Component location. You will find this location on your system by entering:

  gbs3 -e "print component.path"

In Most Cases this will be

  /usr/lib/gambas3/<component_name>

Example

use "gb.args","gb.eval"...

How Libraries are referenced and located

Libraries may be located in a number of locations specific to Gambas3 or by any explicitly defined Path.
These are list in order of search:

 $XDG_DATA_HOME/gambas3/lib"                                   if XDG_DATA_HOME is defined
 /usr/lib/gambas3/<vendor>/<name>:<Version>.gambas
 ~/.local/share/gambas3/lib/<vendor>/<name>:<Version>.gambas
 /usr/lib[/multiarch]/gambas3/<vendor>/<name>:<version>.gambas

For each of the paths found in:

 $LD_LIBRARY_PATH/gambas3/<vendor>/<name>:<Version>.gambas

For each of the locations in:

 $XDG_DATA_DIRS/gambas3/lib/<vendor>/<name>:<Version>.gambas

And for all executable directories listed in:

 $PATH/<vendor>/<name>.gambas

or explicitly in the absolute path format:

 /<user_defined_path>/<name>:<version>.gambas

Or

 /<user_defined_path>/<vendor>.<name>:<version>.gambas

How version numbers are used

Version numbers may be defined and are used as part of the search criteria
may be specified in one of the following ways.
MyBiz is the vendor name for these examples.

MyBiz.mylib: - This will use the highest located version of the library
MyBiz.mylib:1 - This will use the highest located version of version 1 library found
MyBiz.mylib:1.1 - This will use the highest located version of version 1.1 library found
MyBiz.mylib:1.1.3- This will use only the explicitly request library or create and error

Note: Vendor name is not required when specifying absolute paths.

Example

use "myBiz.MyLib:","/home/mylibs/libTest:1","MyLib:","MyBiz.MyLib:1.0","MyBiz.MyLib:1.0.1" ...

Finding Your Library Search Paths

The Following gambas script will display your library search paths

dim gbsver as string = "gambas"&system.version
dim adatapaths as string[]
dim i as integer
Print user.home &/ ".local/share" &/ gbsver &/ "lib"
print "/usr/lib" &/ gbsver
If Env["XDG_DATA_HOME"] <> "" Then
   print  Env["XDG_DATA_HOME"] &/ gbsver &/ "lib"
Endif
If Exist("usr/lib/" &/ System.Architecture) Then
    print "usr/lib/" &/ System.Architecture &/ gbsver
Endif
If Env["LD_LIBRARY_PATH"] <> "" Then
    aDataPaths = Split(Env["LD_LIBRARY_PATH"], ":", "", True)
    For i= 0 To aDataPaths.Max
      print aDataPaths[i] & "/" & gbsver
    Next
Endif
If Env["XDG_DATA_DIRS"] <> "" Then
    aDataPaths = Split(Env["XDG_DATA_DIRS"], ":", "", True)
    For i = 0 To aDataPaths.Max
      print aDataPaths[i] & "/" & gbsver &/ "lib"
    Next
Endif
If Env["PATH"] <> "" Then
    aDataPaths = Split(Env["PATH"], ":", "", True)
    For i = 0 To aDataPaths.Max
      print aDataPaths[i]
    Next
Endif

See also