Writing and Debugging a Basic UNO program

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Enter the following source code in the Basic editor window. The example asks the user for the location of a graphics file and inserts it at the current cursor position of our document. Later, the example will be extended by a small insert graphics autopilot.

  Sub Main
      ' ask the user for a graphics file
      sGraphicUrl = InputBox("Please enter the URL of a graphic file", _
          "Import Graphics", _
      if sGraphicURL = "" then ' User clicked Cancel
          exit sub
      ' access the document model
      oDoc = ThisComponent
      ' get the Text service of the document
      oText = oDoc.getText()
      ' create an instance of a graphic object using the document service factory
      oGraphicObject = oDoc.createInstance("com.sun.star.text.GraphicObject")
      ' set the URL of the graphic
      oGraphicObject.GraphicURL = sGraphicURL
      ' get the current cursor position in the GUI and create a text cursor from it
      oViewCursor = oDoc.getCurrentController().getViewCursor()
      oCursor = oText.createTextCursorByRange(oViewCursor.getStart())
      ' insert the graphical object at the cursor position
      oText.insertTextContent(oCursor.getStart(), oGraphicObject, false)
  End Sub

If help is required on Basic keywords, press F1 while the text cursor is on a keyword. The OpenOffice.org online help contains descriptions of the Basic language as supported by OpenOffice.org.

Starting with the line oDoc = ThisComponent, where the document model is accessed, we use the UNO integration of OpenOffice.org Basic. ThisComponent is a shortcut to access a document model from the Basic code contained in it. Earlier, you created Module1 in FirstStepsBasic.odt, that is, your Basic code is embedded in the document FirstStepsBasic.odt, not in a global library below the My Macros container. The property ThisComponent therefore contains the document model of FirstStepsBasic.odt.

Tip.png Outside document libraries use ThisComponent or StarDesktop.CurrentComponent to retrieve the current document. If access to an open document is required, even if it is not the current document, you have to iterate over the components in StarDesktop.Components, checking their URL property with code similar to the following:
 oComps = StarDesktop.Components
  oCompsEnum = oComps.createEnumeration()
  while oCompsEnum.hasMoreElements()
      oComp = oCompsEnum.nextElement()
      ' not all desktop components are necessarily models with a URL
      if HasUnoInterfaces(oComp, "com.sun.star.frame.XModel") then
        print oComp.getURL()

Breakpoint.png To debug the program, put the cursor into the line oDoc = ThisComponent and click the Breakpoint icon in the macro bar.
MacroRun.png The Run icon launches the first Sub in the current module. Execution stops with the first breakpoint.
SingleStep.png Now step through the program by clicking the Single Step icon.
Macros.png Click the Macros icon if you need to run a Sub other than the first Sub in the module.. In the OpenOffice.org Basic Macros dialog, navigate to the appropriate module, select the Sub to run and press the Run button.

To observe the values of Basic variables during debugging, enter a variable name in the Watch field of the Basic editor and press the Enter key to add the watch, or point at a variable name with the mouse cursor without clicking it. In the example below, we can observe the variables sGraphicUrl and oGraphicObject:

A macro in the source editor window

Since OpenOffice.org 2.0 it is also possible to inspect the values of UNO objects in the Basic debugger during runtime.

Content on this page is licensed under the Public Documentation License (PDL).
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