FOP Extensions

+ Extensions +

+FOP provides an extension mechanism to add extra functionality. There +are a number of different types of extensions that apply to different +steps when converting FO into the rendered output. +

+ Extensions +

+SVG Graphic - This applies to svg and any other xml document that +can be converted into svg in the output. All that is required is +the element mapping for the xml and a converter that changes the +document into svg. This conversion is done in the FO Tree. The +conversion is done by the top level element of the namespace +or in the case of an external image a Converter. +

+XML Document - Instead of converting the document into svg it +can be passed directly to the renderer. The renderer will need +to have a handler for the xml document. This handler can add +information directly to the output document. +

+Output Document - This is used to add document level information +to the output result. Such an extension will set information that +is passed to the output document. There needs to be a handler for +the output information which creates a document level result. +

+FO Area - This is where an extension creates an normal area in +the Area Tree. This is useful when the normal FO objects +cannot create the area in the way that is needed. +

+Resolveable - In some cases it may require information to be +resolved for information such as page numbers. This can apply +to the XML Document, FO Area or output document extensions. +

+- Add a string ['(Continued)'] to a table header if the table spans +multiple pages. These tables are part of the content and can start +anywhere in the page. +

+- Separate page number display for a subsection. ie. - master document +is page 4 of 7, but subsection is page 2 of 3. + +

+ Examples +

+Plan - The plan extension is a simple SVG graphic extension. +Given a plan document either inside an InstreamForeignObject +or as an external graphic, it converts the plan document into +an svg graphic. The svg graphic is then passed through the +Area Tree to the Renderer. The Renderer then renders the svg +graphic as normal. +

+PDF Outline - This is output document extension. If rendering to +pdf and this extensionis used then the bookmark information is +passed to the pdf document. This information is then set on the +document. +

+PDF Additions - This can be done with an XML Document extension. +A simple xml document is defined that provides the appropriate +information. When the document is rendered a handler converts the +document into PDF markup. +

+eg. +Search]]> + +to result in a text box referencing the following PDF action: +>]]> + +

+ +