Calling Python Scripts from Basic
Calling Python scripts from LibreOffice Basic macros is possible, and valuable features can be obtained such as:
ComputerName identification or OSName detection are possible,
Basic FileLen() function and com.sun.star.ucb.SimpleFileAccess.getSize() API function exhibit a 2 Gigabytes file size upper limit that Python helps to overcome,
com.sun.star.util.PathSettings can be normalized,
and many more.
A reasonable exposure to LibreOffice Basic and to Application Programming Interface (API) features is recommended prior to perform inter-language calls from Basic to Python, to JavaScript or any other script engine.
Retrieving Python Scripts
Python scripts can be personal, shared, or embedded in documents. In order to execute them, LibreOffice Basic needs to be provided with Python script locations. Locating com.sun.star.script.provider.XScript interface compliant UNO objects allows the execution of Python scripts:
Option Explicit
Public Function GetPythonScript(macro As String, _
Optional location As String) As com.sun.star.script.provider.Xscript
''' Grab Python script object before execution
' Arguments:
' macro : as "library/module.py$macro" or "module.py$macro"
' location: as "document", "share", "user" or ENUM(eration)
' Result:
' located com.sun.star.script.provider.XScript UNO service'''
If IsMissing(location) Then location = "user"
Dim mspf As Object ' com.sun.star.script.provider.MasterScriptProviderFactory
Dim sp As Object ' com.sun.star.script.provider.XScriptProvider compatible
Dim uri As String
If location="document" Then
sp = ThisComponent.getScriptProvider()
Else
mspf = CreateUNOService("com.sun.star.script.provider.MasterScriptProviderFactory")
sp = mspf.createScriptProvider("")
End If
uri = "vnd.sun.star.script:"& macro &"?language=Python&location="& location
GetPythonScript = sp.getScript(uri)
End Function ' GetPythonScript
Executing Python Scripts
Syntax
workstation_name = script.invoke(Array(), Array(), Array())
opSysName = script.invoke(Array(), in_outs, Array()) ' in_out is an Array
file_len = script.invoke(Array(systemFilePath), Array(), Array())
normalizedPath = script.invoke(Array(systemFilePath), Array(), Array())
Embedded Scripts Examples
Below ComputerName, and GetFilelen routines are calling their Python counterparts, using aforementioned GetPythonScript function. Exception handling is not detailed.
Option Explicit
Option Compatible ' Properties are supported
Private scr As Object ' com.sun.star.script.provider.XScript
Private Property Get ComputerName As String
'''Workstation name'''
scr = GetPythonScript("Platform.py$computer_name", "document")
ComputerName = scr.invoke(Array(), Array(), Array())
End Property ' ComputerName
Private Function GetFilelen(systemFilePath As String) As Currency
'''File size in bytes'''
scr = GetPythonScript("Os/Path.py$get_size", Script.ISEMBEDDED)
GetFilelen = scr.invoke(Array(systemFilePath), Array(), Array(),)
End Function ' GetFilelen
Private Type _SCRIPT_LOCATION
ISEMBEDDED As String ' document script
ISPERSONAL As String ' user script
ISSHARED As String ' LibreOffice macro
End Type ' _SCRIPT_LOCATION
Public Function Script() As Object ' Text enumeration
Static enums As _SCRIPT_LOCATION : With enums
If .ISEMBEDDED = "" Then
.ISEMBEDDED = "document" ' document script
.ISPERSONAL = "user" ' user scripts
.ISSHARED = "share" ' LibreOffice macro
End If : End With ' enums
Script = enums
End Function ' Script
Two different Python modules are called. They can either be embedded in the current document, either be stored on the file system. Argument type checking is skipped for clarity:
Platform.py
# -*- coding: utf-8 -*-
from __future__ import unicode_literals
import platform
def computer_name() -> str:
return platform.node()
def OSname() -> str:
return platform.system()
Os/Path.py
# -*- coding: utf-8 -*-
from __future__ import unicode_literals
import os.path
def get_size(systemFilePath: str) -> str:
return str(os.path.getsize(systemFilePath))
def normalyze(systemPath: str) -> str:
return os.path.normpath(systemPath)
Personal or Shared Scripts Examples
The calling mechanism for personal or shared Python scripts is identical to that of embedded scripts. Library names are mapped to folders. Computing LibreOffice user profile and shared modules system file paths can be performed as detailed in Getting session information. Below OSName, HelloWorld and NormalizePath routines are calling their Python counterparts, using aforementioned GetPythonScript function. Exception handling is not detailed.
Option Explicit
Option Compatible ' Properties are supported
Private scr As Object ' com.sun.star.script.provider.XScript
Private Property Get OSName As String
'''Platform name as "Linux", "Darwin" or "Windows"'''
scr = GetPythonScript("Platform.py$OSname", Script.ISPERSONAL)
OSName = scr.invoke(Array(), Array(), Array())
End Property ' OSName
Private Sub HelloWorld()
'''LibreOffice Python shared sample'''
scr = GetPythonScript("HelloWorld.py$HelloWorldPython", Script.ISSHARED)
scr.invoke(Array(), Array(), Array(),)
End Sub ' HelloWorld
Public Function NormalizePath(systemFilePath As String) As String
'''Strip superfluous '\..' in path'''
scr = GetPythonScript("Os/Path.py$normalyze", "user")
NormalizePath = scr.invoke(Array(systemFilePath), Array(), Array())
End Function ' NormalizePath
Python standard modules
LibreOffice embedded Python contains many standard libraries to benefit from. They bear a rich feature set, such as but not limited to:
argparse Parser for command-line options, arguments and sub-commands
cmath Mathematical functions for complex numbers
csv CSV files reading and writing
datetime Genuine date and time types
json JSON encoder and decoder
math Mathematical functions
re Regular expression operations
socket Low-level networking interface
sys System-specific parameters and functions
unittest and trace Unit testing framework and Track Python execution
xml.etree.ElementTree ElementTree XML API