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# Llamar macros en Basic desde Python

Es posible llamar macros escritas en LibreOffice Basic desde secuencias de órdenes en Python y sacar provecho de funcionalidades tales como:

- Funciones de registro sencillas para la consola de traza de la biblioteca Access2Base,

- funciones de E/S en pantalla InputBox y MsgBox basadas en Basic para facilitar el desarrollo con Python,

- interrupción de la ejecución de la secuencia escrita en Python por llamada a Xray para examinar las variables.

The LibreOffice Application Programming Interface (API) Scripting Framework supports inter-language script execution between Python and Basic, or other supported programming languages for that matter. Arguments can be passed back and fourth across calls, providing they represent primitives data types that both languages recognize, and assuming that the Scripting Framework converts them appropriately.

Es recomendable familiarizarse con los módulos estándares de Python y las funcionalidades de la API de LibreOffice antes de efectuar llamadas entre los lenguajes Python, Basic, JavaScript o cualquier otro motor de secuencias de órdenes.

When running Python scripts from an Integrated Development Environment (IDE), the LibreOffice nested Basic engine may be absent. Avoid Python to LibreOffice Basic calls in such context. However Python environment and Universal Networks Objects (UNO) are fully available. Refer to Setting Up an Integrated IDE for Python for more information.

## Recuperación de secuencias de órdenes en Basic en LibreOffice

LibreOffice Basic macros can be personal, shared, or embedded in documents. In order to execute them, Python run time needs to be provided with Basic macro locations. Implementing the com.sun.star.script.provider.XScriptProvider interface allows the retrieval of executable scripts:

    		 import uno
    		 from com.sun.star.script.provider import Xscript

    		 def getBasicScript(macro='Main', module='Module1', library='Standard',
    		         isEmbedded=False) -> XScript:
    		     '''Tomar el objeto de secuencia de Basic antes de la invocación.'''
    		     ctx = uno.getComponentContext()
    		     smgr = ctx.ServiceManager
    		     if isEmbedded:
    		         desktop = smgr.createInstanceWithContext('com.sun.star.frame.Desktop', ctx)
    		         scriptPro = desktop.CurrentComponent.getScriptProvider()
    		         location = "document"
    		     else:
    		         mspf = smgr.createInstanceWithContext(
    		             "com.sun.star.script.provider.MasterScriptProviderFactory", ctx)
    		         scriptPro = mspf.createScriptProvider("")
    		         location = "application"
    		     scriptName = "vnd.sun.star.script:"+library+"."+module+"."+macro+ \
    		                  "?language=Basic&location="+location
    		     xScript = scriptPro.getScript(scriptName)
    		     return xScript

## Ejecución de secuencias de órdenes en Basic en LibreOffice

La documentación del Kit de desarrollo de software (SDK) de LibreOffice correspondiente a la interfaz com.sun.star.script.provider.XScript detalla la convención para efectuar llamadas entre lenguajes de programación. La invocación de funciones requere tres matrices:

- la primera enumera los argumentos de la rutina llamada

- la segunda identifica los argumentos modificados

- la tercera almacena los valores devueltos

### Sintaxis de Python

results = script.invoke((prompt,buttons,title), (), ())

script.invoke((message,), tuple, ())

script.invoke((args), (), results)

### Ejemplos de secuencias de órdenes personales y compartidas

Examples in Input/Output to Screen detail Python to Basic invocation calls. Monitoring Document Events illustrates the usage of *args Python idiom to print a variable number of parameters to Access2Base logging console dialog.

At time of development you can interrupt Python script execution using Xray extension in order to inspect properties and methods of UNO objects. The ASPO extension debugger allows object introspection using either Xray either MRI extensions.

    	  def xray(myObject):
    	  	  script = getBasicScript(library="XrayTool", module="_Main", macro="Xray")
    	  	  script.invoke((myObject,), (), ())

### Ejemplos de secuencias de órdenes incrustadas en documentos

*argsPython simplified syntax can be used in conjunction with LibreOffice Basic routines that accept a variable number of arguments. Below Print and SUM Python functions call their Basic Print and SUM counterparts, using aforementioned getBasicScript function. Exception handling is not detailed.

    	  # -*- coding: utf-8 -*-
    	  from __future__ import unicode_literals

    	  def Print(*args):
    	      """Muestra las cadenas o expresiones numéricas especificadas en un cuadro de diálogo."""
    	      xScript = getBasicScript("Print", "Scripting", embedded=True)
    	      xScript.invoke((args), (), ())

    	  def SUM(*args):
    	      """SUM the specified number expression."""
    	      xScript = getBasicScript("SUM", "Scripting", embedded=True)
    	      res = xScript.invoke((args), (), ())
    	      return res[0]

    	  # def getBasicScript()  # see above

    	  def playWithArgs():
    	      Print("Fun with *args ", -9.81, 297864.681974, 8762E-137)
    	      Print(SUM(45, -9.81, 297864.681974))
    	      Print(SUM(45, -9.81, 297864.681974, 8762E+137))

    	  g_exportedScripts = (playWithArgs,)

The LibreOffice Basic Print and SUM document-based routines accept a variable number of arguments. The Private or Public attributes have no effect. The arguments type checking is skipped for clarity.

    	  Option Compatible ' "Standard.Scripting" module
    	  Option Explicit

    	  Private Sub Print(ParamArray args() As Variant, Optional sep As String = " ")
    	      ''' Print item list of variable number '''
    	      ' se aceptan todos los argumentos convertibles de CStr()
    	      Dim str As String, i As Integer
    	      If UBound(args) >= 0 Then
    	          For i = 0 To UBound(args)
    	              str = str + Cstr(args(i))+ sep
    	          Next i
    	      End If
    	      Print str
    	      End Sub ' Standard.Scripting.Print()

    	  Public Function SUM(ParamArray args() As Variant) As Variant
    	      ''' SUM a variable list of numbers '''
    	      Dim ndx As Integer
    	      If UBound(args) >= 0 Then
    	          For ndx = 0 To UBound(args)
    	              SUM = SUM + args(ndx)
    	          Next ndx
    	      End If
    	  End Function ' Standard.Scripting.SUM()

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