Filter Options

OpenOffice.org Developer's Guide

Office Development

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• OpenOffice.org Application Environment

• Desktop Environment
• Framework API

• Frame-Controller-Model Paradigm in OpenOffice.org
• Frames
• Controllers
• Windows
• Dispatch Framework

• Using the Desktop
• Using the Component Framework

• Getting Frames, Controllers and Models from Each Other
• Frames
• Controllers
• Models
• Window Interfaces

• Creating Frames Manually
• Handling Documents

• Closing Documents
• Storing Documents

• Using the Dispatch Framework

• Command URL
• Processing Chain
• Dispatch Process
• Dispatch Results
• Dispatch Interception

• Java Window Integration

• Common Application Features

• Internationalization

• Overview and Using the API
• Implementing a New Locale

• Linguistics

• Using Spellchecker
• Using Hyphenator
• Using Thesaurus
• Events
• Implementing a Spell Checker
• Implementing a Hyphenator
• Implementing a Thesaurus

• Integrating Import and Export Filters

• Filtering Process
• Filters
• Type Detection and its Configuration
• Properties of a Type
• Properties of a Filter
• Filter Options
• Properties of a FrameLoader
• Document API Filter Development

• XML Based Filter Development

• Writing the Filtering Component
• The Importer
• The Exporter
• XML Filter Detection

• Number Formats

• Managing Number Formats
• Applying Number Formats

• Document Events
• Path Organization

• Path Settings
• Path Variables

• Predefined Variables
• Custom Path Variables
• Resolving Path Variables

• OpenOffice.org Single Sign-On API
• RDF metadata

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A filter may need some additional information before it can import or export properly. As an example, the OpenOffice.org filter "Text - txt - csv (StarCalc)" needs a separator used to detect columns. This information is transported as a property FilterData inside the MediaDescriptor. The value depends on the filter implementation and is not specified (type "any"). It's up to the filter to deal with it and handle it properly. The MediaDescriptor may contain another property of type string named FilterOptions. It can be used if the flexibility of an any is not required and the small overhead to retrieve the string from the any is unwanted. The filter must document which of these properties it uses and how the information transported by it must be shaped.

There are two possible origins of the FilterData or FilterOptions property:

• the loading or storing process is triggered from code that is able to provide the necessary information and provides it in the code
• a user has entered the data into a dialog that OpenOffice.org has presented to him and retrieved it from the dialog after the user closed it

The second case requires that the configuration of the filter uses the properties "UsesOptions" and "UIComponent".

A generic UI that uses a filter as one part of a load request does not know about special parameters. Normally, the FilterData are not set inside the media descriptor, therefore a filter should use default values. It should be possible to prompt the user for better values by registering another component that implements the service com.sun.star.ui.dialogs.FilterOptionsDialog. It is called UIComponent. It enables a filter developer to query for user options before the filter operation is performed. It does not show this dialog inside the filter, because any UI can be suppressed, for example, an external application uses the API of OpenOffice.org for scripting running in a hidden mode. The code that uses the filter decides if it is necessary and allowed to use the dialog. If not, the filter lives with missing parameters and uses default values. If it is not possible to have defaults, it aborts the filter() request returning false.

The UIComponent provides an interface com.sun.star.beans.XPropertyAccess used to set the whole MediaDescriptor before executing the dialog using the FilterOptionsDialog interface com.sun.star.ui.dialogs.XExecutableDialog and retrieves the changes. The user of the dialog decides if the changes are merged with the original ones or replaced. Using the whole descriptor provides the information about the environment in which the filter works, for example, the URL or information about preview mode. The parameters of a filter depend on it. Normally a UIComponent is shown if no FilterData or FilterOptions are part of the descriptor, so that they are added. In the case where they exist, it is necessary to change it.

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