Re: [Flightgear-devel] Loading an XML file using EasyXML
On Fri, 20 Aug 2004 22:01:43 +0200 "Frederic Bouvier" <[EMAIL PROTECTED]> wrote: I think Jon wants to preserve the current JSBsim syntax and not use the property syntax. -Fred Well, perhaps. The thing is, certain items that would be parsed from the configuration file, such as landing gear, aero coefficients, engines, and flight control components, are _instantiated_ when they are read from the config file. The parsing process does not simply read property values and assign them. The configuration of the specific simulation is formed. Also, the interest is in allowing each class to extract its own values from the config file. That makes it a little trickier. Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Loading an XML file using EasyXML
Erik Hofman wrote: > Jon S Berndt wrote: > > > So, my question is: What is the philosophy behind loading various > > classes with their own data from the config file using EasyXML callbacks? > > You could store the data into a property tree and let every subsystem > scan it's own directory. This tree could be detached from the main tree > and could be removed safely after initialization is done. I think Jon wants to preserve the current JSBsim syntax and not use the property syntax. However Jon, you can have a look at the readProperties functions here http://www.simgear.org/doxygen/props__io_8hxx.html that will show you a non trivial use of readXML to retrieve the property tree. -Fred ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Loading an XML file using EasyXML
On Fri, 20 Aug 2004 21:40:28 +0200 Mathias Fröhlich <[EMAIL PROTECTED]> wrote: On Freitag, 20. August 2004 21:10, Jon S Berndt wrote: But also an aircraft is built like such a tree. The top node is the Some aircraft are even built OUT OF trees. ;-) aircraft itself. This one has a flightcontrolsystem, some object containing the aerodynamic properties of the aircraft, a list of engines, a list of undercarriage elements and so on. Erik's approach might work. I will have to "play" with the parsing to see different approaches, and how they might work. Thanks, Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Loading an XML file using EasyXML
On Freitag, 20. August 2004 21:10, Jon S Berndt wrote: > So, my question is: What is the philosophy behind loading various > classes with their own data from the config file using EasyXML > callbacks? This kind of xml parsers is designed to build a 'tree' of objects representing the data stored in the 'tree' of the xml file. Thus this kind of parsers fit very well for the property /tree/ example Erik mentioned. But also an aircraft is built like such a tree. The top node is the aircraft itself. This one has a flightcontrolsystem, some object containing the aerodynamic properties of the aircraft, a list of engines, a list of undercarriage elements and so on. Greetings Mathias -- Mathias Fröhlich, email: [EMAIL PROTECTED] ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Loading an XML file using EasyXML
Jon S Berndt wrote: So, my question is: What is the philosophy behind loading various classes with their own data from the config file using EasyXML callbacks? You could store the data into a property tree and let every subsystem scan it's own directory. This tree could be detached from the main tree and could be removed safely after initialization is done. Erik ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Loading an XML file using EasyXML
On Fri, 20 Aug 2004 20:55:18 +0200 Mathias Fröhlich <[EMAIL PROTECTED]> wrote: On Freitag, 20. August 2004 18:48, Jon S Berndt wrote: Can someone tell me what the process is once a file has been opened and is being parsed by EasyXML? What do the callbacks do ... what is the standard procedure for reading in the attibutes and elements and data? See: http://www.simgear.org/doxygen/easyxml_8hxx.html It is a quite neat implementation. And I think that using integrating this provides is a good chance to seperate configuration data from state data. Yes, I've seen that page. I've written (now) two applications that use the EasyXML class, and it is a very nice (and Easy) class to use. With the plotting application, it was not too difficult to use it (even if I did so incorrectly). There was one class that was subclassed from XMLVisitor, and it included all the plotting parameters I needed. However, in the case of JSBSim, there are now several classes that read in data from the configuration file (FGFDMExec does the initial read, and hands off the config file handle to other classes to let them read in their own data). The Aerodynamics, MassBalance, Aircraft, Output, etc. classes currently all read in their own data from the configuration file. Today, I have written a class that parses JSBSim format config files. Within the callbacks I simply echo the information read from the files. Currently, FGXMLParser (the name of the potential new class to replace FGConfigFile) can parse the config file, but then the question is: what do I do, now. Remember, currently in JSBSim each file reads in its own data as the config file class encounters the relevant sections in the config file. With FGXMLParser we have callbacks - this is philosophically different from FGConfig File. So, my question is: What is the philosophy behind loading various classes with their own data from the config file using EasyXML callbacks? Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Loading an XML file using EasyXML
On Freitag, 20. August 2004 18:48, Jon S Berndt wrote: > Can someone tell me what the process is once a file has been opened > and is being parsed by EasyXML? What do the callbacks do ... what is > the standard procedure for reading in the attibutes and elements and > data? See: http://www.simgear.org/doxygen/easyxml_8hxx.html It is a quite neat implementation. And I think that using integrating this provides is a good chance to seperate configuration data from state data. Greetings Mathias -- Mathias Fröhlich, email: [EMAIL PROTECTED] ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
