Document Converter (Customization Policy)
Represents a custom executable file that takes a document of one file type and generates a copy of that file in another file type.
Real World Example
A graphics arts team uses Microsoft Office SharePoint Server 2007 to store larger files from a common computer aided design (CAD) drawing file format, but they frequently need to use a smaller high-resolution bitmap image based on the CAD image. They ask a developer to create a document converter feature that takes the CAD image format as input and exports a high-resolution image based on some configured settings.
Technical Details
A document converter uses an executable file and some forms pages to convert documents from a source file format into a destination format. A separate control template is used to control the settings for the conversion process.
The following is an example of a Document Converter feature from the Windows SharePoint Services 3.0 SDK.
<Elements xmlns="https://schemas.microsoft.com/sharepoint/">
<DocumentConverter ID="{3f8ae156-93dc-46de-bcb3-0a89416a20b3}" Name="FileTypeA to FileTypeB" App="FTA2FTB.exe" From="fta" To="ftb" ConverterUIPage="FTA2FTB.aspx" ConverterSpecificSettingsUI="FTA2FTBConfig.aspx" ConverterSettingsForContentType="FTA2FTBConfig.ascx" />
</Elements>
Document conversions can be resource intensive, especially when performed in batches, so Microsoft Office SharePoint Server 2007 relies on two services, the DocConversionLoadBalancerService and the DocConversionLauncherService, to manage the load balancing, prioritizing, and scheduling of the conversions. When a user initiates a document conversion, either through the user interface or object model, Office SharePoint Server 2007 passes the document conversion request to these two services. The DocConversionLauncherService service actually calls the document converter. When called, the document converter takes the original file and generates a converted copy. Office SharePoint Server 2007 then takes the converted copy and performs post-processing actions on it.
The document converter executable files are installed by default in the following path:
%PROGRAMFILES%\Microsoft Office Servers\12.0\TransformApps
Additional detailed technical information about document converters can be found in the Office SharePoint Server 2007 SDK or online at MSDN in the Page Publishing Using Document Converters overview section.
Support Details
Both the DocConversionLoadBalancerService and DocConversionLauncherService services must be enabled and configured in the server farm before conversions can occur.
Because of memory usage and CPU performance, a document converter could cause performance problems for any Web application and environment that it is installed on.
Multiple document converters can be registered that produce the same output file type, which can make it difficult to determine the converter that generated a specific output file. Internally SharePoint Products and Technologies use a GUID when determining if a converter has run for a specific file, and this would be used to determine the converters that have run.
Document converters are set at the Web application level and cannot be disabled for a specific site or document library.