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PropertyList XML files: Difference between revisions
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http://www.mail-archive.com/flightgear-devel@flightgear.org/msg00121.html
m (property indexing: http://www.mail-archive.com/flightgear-devel@flightgear.org/msg04184.html) |
(http://www.mail-archive.com/flightgear-devel@flightgear.org/msg00121.html) |
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A custom-designed XML format for panels, sound, animations, FDMs, etc. could be *much* less verbose, but then we'd be managing n different XML-based formats and parsing libraries. | A custom-designed XML format for panels, sound, animations, FDMs, etc. could be *much* less verbose, but then we'd be managing n different XML-based formats and parsing libraries. | ||
One advantage of the XML representation is its conceptual simplicity. Every element except for the root PropertyList container represents exactly one property, and every attribute represents metadata for the property associated with its element. | |||
Not everything that is read from an XML file resides in the main property tree; some subsystems also use XML files for initial configuration information. There are different kinds of data. The property tree is meant to represent the shared state of the program; when a subsystem happens to use an XML file to set up its internal state -- information that is of no use to the rest of the program and that cannot be changed without a reinit. Temporary trees are usually deleted as soon as the subsystem is set up (i.e. they exist for perhaps 0.1 sec). We could just as easily use another format for internal initialization, but since the XML support is already available, it was the easiest route. | Not everything that is read from an XML file resides in the main property tree; some subsystems also use XML files for initial configuration information. There are different kinds of data. The property tree is meant to represent the shared state of the program; when a subsystem happens to use an XML file to set up its internal state -- information that is of no use to the rest of the program and that cannot be changed without a reinit. Temporary trees are usually deleted as soon as the subsystem is set up (i.e. they exist for perhaps 0.1 sec). We could just as easily use another format for internal initialization, but since the XML support is already available, it was the easiest route. | ||