Hello list, we are near to finish our TXT proposal called "Extension of CQL to match abilities of Filter"
http://docs.codehaus.org/display/GEOTOOLS/Extention+of+CQL+to+match+abilities+of+Filter In the inception phase we picked up the suggestions of a lot of people. Then we were working to provide the better solution for the great majority. In the next list I try to explain some decisions. 1- IN Predicate and Id filter We arrived to a sentence like this ID IN states1,states.2,states.3 I found a problem to write the grammar for the id values, because its pattern is equal to "identifier" (property or attributes) token. Then the lexical analysis is not possible. Well, I solved this issue using the string pattern then the id values must be between quotes ('states1','states.2','states.3' ). Finally, some user suggested to add something like the IN sentence (from SQL) to avoid query like x=1 or x=2 or x=3 .... . Well thinking in the compatibility with this sentence I thought Id Predicate should be consistent with this. Then I added the parenthesis "(" ")", the final result was id predicate ID IN ( 'states1', 'states.2' , 'states.3' ) in predicate length IN (4100001,4100002, 4100003 ) 2- BBOX extension CQL allows to write BBOX(the_geom, 10.0, 20.0, 30.0, 40.0) The idea was extend it to allow to write a sentence like BBOX( buffer( the_geom , 10) , 10.0, 20.0, 30.0, 40.0) To implement this was needed to change the actual implementation of org.geotools.filter.FilterFactoryImpl Class public BBOX bbox( Expression e, double minx, double miny, double maxx, double maxy, String srs) that limit the first parameter "e" to instance of "PropertyNames". (Jody suggested me to make a proposal, I will do it) - Reference Interested people can find the source code in http://svn.geotools.org/trunk/modules/library/cql There is a "light" test that could be a good overview in org.geotools.filter.text.txt.TXTTest The package org.geotools.filter.text.txt contains many test cases if you are interested in more details. Finally, I would like the next step in the process. Maybe, is it time to start the voting?. Could I begin to organize the user documentation in http://docs.codehaus.org/display/GEOTDOC/14+CQL ? -- Mauricio Pazos www.axios.es ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Geotools-devel mailing list Geotools-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/geotools-devel
