I'm using the post 1.31.1 version of boost, which has a much nicer read_graphviz function. I'm wondering if there is a way to "ignore" unwanted properties, something akin to sending them to /dev/null. My present experience is that if an unexpected property is found, an exception is thrown. Is there a way to express that a given property is to be ignored? Better yet, is there a way to say that all unexpected properties are to be ignored?
Hello Jeffrey, It IS possible to prevent exception throws, but it will require a little work on your part. dynamic_properties has a constructor of the form: dynamic_properties( const boost::function< std::auto_ptr<dynamic_property_map> ( const std::string&, const boost::any&, const boost::any&) >& fn) If an attempt is made to put() a value for a non-existent key, then this function is used as a factory to create a new dynamic_property_map for those values. You can use this mechanism to prevent exceptions: 1) Create a class that derives from dynamic_property_map but does nothing interesting with get or put 2) Create a factory function that returns std::auto_ptr<dynamic_property_map> of these objects 3) Pass this as the argument to your dynamic_property_map constructor. HTH, ron On Jan 11, 2007, at 7:35 PM, Jeffrey Holle wrote:
I'm using the post 1.31.1 version of boost, which has a much nicer read_graphviz function.
I'm wondering if there is a way to "ignore" unwanted properties, something akin to sending them to /dev/null.
My present experience is that if an unexpected property is found, an exception is thrown.
Is there a way to express that a given property is to be ignored?
Better yet, is there a way to say that all unexpected properties are to be ignored?
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On Tue, 30 Jan 2007 12:02:23 -0500, Ronald Garcia wrote:
It IS possible to prevent exception throws, but it will require a little work on your part. dynamic_properties has a constructor of the form: dynamic_properties( const boost::function< std::auto_ptr<dynamic_property_map> ( const std::string&, const boost::any&, const boost::any&) >& fn)
If an attempt is made to put() a value for a non-existent key, then this function is used as a factory to create a new dynamic_property_map for those values. You can use this mechanism to
Does anyone have a code example of a reasonable implementation of this dynamic_property_map functor technique to read graphviz dot files with arbitrary properties? I've been trying to extract and adapt the bgl python library's nice read_graphviz function, which implements this dynamic_property_map functor technique, but it is still not functional after several hours of template struggles. I have been using a (long) hard-coded property list for read_graphviz in my code for the past year, but there are so many obscure dot file properties that it is still very hit-or-miss. Thanks.
Hi, I have made an addition to dynamic_property_map in the current CVS so that you can construct the dynamic properties object with the "ignore_other_properties" generator as follows: boost::dynamic_properties dp2(boost::ignore_other_properties); and read_graphviz will not throw an exception if you are not prepared for a particular property. HTH, ron On Mar 16, 2007, at 4:01 PM, Braddock Gaskill wrote:
On Tue, 30 Jan 2007 12:02:23 -0500, Ronald Garcia wrote:
It IS possible to prevent exception throws, but it will require a little work on your part. dynamic_properties has a constructor of the form: dynamic_properties( const boost::function< std::auto_ptr<dynamic_property_map> ( const std::string&, const boost::any&, const boost::any&)
& fn)
If an attempt is made to put() a value for a non-existent key, then this function is used as a factory to create a new dynamic_property_map for those values. You can use this mechanism to
Does anyone have a code example of a reasonable implementation of this dynamic_property_map functor technique to read graphviz dot files with arbitrary properties?
I've been trying to extract and adapt the bgl python library's nice read_graphviz function, which implements this dynamic_property_map functor technique, but it is still not functional after several hours of template struggles.
I have been using a (long) hard-coded property list for read_graphviz in my code for the past year, but there are so many obscure dot file properties that it is still very hit-or-miss.
Thanks.
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participants (3)
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Braddock Gaskill -
Jeffrey Holle -
Ronald Garcia