Python : Programming with Python

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# Programming with Python Scripts

A Python macro is a function within a .py file, identified as a module. Unlike LibreOffice Basic and its dozen of UNO objects functions or services, Python macros use the XSCRIPTCONTEXT UNO single object, shared with JavaScript and BeanShell. The g_exportedScripts global tuple explicitly lists selectable macros from a module. Python modules hold autonomous code logic, and are independent from one another.

## XSCRIPTCONTEXT Global Variable

Genuine Basic UNO facilities can be inferred from XSCRIPTCONTEXT global variable. Refer to LibreOffice API for a complete description of XSCRIPTCONTEXT. XSCRIPTCONTEXT methods summarize as:

Methods | Description | Mapped in Basic as
--- | --- | ---
getDocument() | The document reference on which the script can operate. | ThisComponent
getDesktop() | The desktop reference on which the script can operate. | StarDesktop
getComponentContext() | The component context which the script can use to create other UNO components. | GetDefaultContext

HelloWorld and Capitalise installation shared scripts illustrate UNO-related macros making use of XSCRIPTCONTEXT global variable.

Python standard output file is not available when running Python macros from Tools - Macros - Run Macro menu. Refer to Input/Output to Screen for more information.

## Module import

XSCRIPTCONTEXT is not provided to imported modules.

LibreOffice Basic libraries contain classes, routines and variables, Python modules contain classes, functions and variables. Common pieces of reusable Python or UNO features must be stored in My macros within (User Profile)/Scripts/python/pythonpath. Python libraries help organise modules in order to prevent module name collisions. Import uno.py inside shared modules.

Genuine BASIC UNO facilities can be inferred using uno.py module. Use Python interactive shell to get a complete module description using dir() and help() Python commands.

Functions | Description | Mapped in Basic as
--- | --- | ---
absolutize() | Returns an absolute file URL from the given URLs. |
createUnoStruct() | Creates a UNO struct or exception given by typeName. | CreateUNOStruct()
fileUrlToSystemPath() | Returns a system path. | ConvertFromURL()
getClass() | Returns the class of a concrete UNO exception, struct, or interface. |
getComponentContext() | Returns the UNO component context used to initialise the Python runtime. | GetDefaultContext()
Enum() getConstantByName() | Looks up the value of an IDL constant by giving its explicit name. | See API constant groups
isInterface() | Returns True, when obj is a class of a UNO interface. |
systemPathToFileUrl() | Returns a file URL for the given system path. | ConvertToURL()

LibreLogo, NamedRanges, SetCellColour and TableSample preinstalled scripts use uno.py module.

## More Python-Basic samples

Python UNO | Basic UNO features
--- | ---
ctx = uno.getComponentContext() smgr = ctx.getServiceManager() obj = smgr.createInstanceWithContext( .. , ctx) | CreateUnoService()
See Opening a Dialog | CreateUnoDialog()
See Creating a Listener | CreateUnoListener()
See UNO data types | CreateUnoValue() CreateObject()
Use "==" or "!=" comparison operators | EqualUnoObjects()
ctx = uno.getComponentContext() smgr = ctx.getServiceManager() | GetProcessServiceManager()
def hasUnoInterfaces(obj, *interfaces): return set(interfaces).issubset(t.typeName for t in obj.Types) | HasUnoInterfaces()
| IsUnoStruct()
ctx = uno.getComponentContext() smgr = ctx.getServiceManager() DESK = 'com.sun.star.frame.Desktop' desktop = smgr.createInstanceWithContext(DESK , ctx) | StarDesktop
desktop = smgr.createInstanceWithContext(DESK , ctx) doc = desktop.CurrentComponent | ThisComponent

## Importing an embedded Module

Similarly to LibreOffice Basic that supports browsing and dynamic loading of libraries, Python libraries can be explored and imported on demand. For more information on library containers, visit LibreOffice Application Programming Interface (API) or download LibreOffice Software Development Kit (SDK).

Importing a Python document embedded module is illustrated below, exception handling is not detailed:

                import uno, sys, zipimport

                def load_library(library_name: str, module_name=None):
                    """ load library and import module

                    Adapted from 'Bibliothèque de fonctions' by Hubert Lambert
                    at https://forum.openoffice.org/fr/forum/viewtopic.php?p=286213"""
                    doc = XSCRIPTCONTEXT.getDocument()  # current document
                    url = uno.fileUrlToSystemPath( \
                        '{}/{}'.format(doc.URL, 'Scripts/python'+library_name))  # ConvertToURL()
                    if not url in sys.path:  # add path if necessary
                        sys.path.insert(0, url)  # doclib takes precedence
                    if module_name:  # import if requested
                        return zipimport.zipimporter(url).load_module(module_name)

                def import_embedded_python():
                    ui = load_library("my_gui",'screen_io')  # add <lib> path + import <module>
                    ui.MsgBox(sys.modules.keys())

                g_exportedScripts = (import_embedded_python,)  # Public macros

Related Topics

Basic UNO Objects, Functions and Services

Importing Python Modules

Input/Output to Screen

LibreOffice Python Scripts Help