Using IParsingActions

Minimal implementation

The following minimal implementations can be used as a starting point for creating your own implementation. Just add an implementation to the methods you are interested in. The listed methods are all the ones that will be called by our parser for the corresponding tpye.

Note

• You can remove any of the shown methods, not overriden once are noop (i.e. do nothing)
• You can add new methods, but be sure to not use any of the names from IParsingActions.
• If you get a “parsing failed!” error, you probably did something wrong with your implementation.

Multipoint

import GSTPy

class MultipointCallback(GSTPy.IParsingActions):
    def set_name(self, name):
        pass

    def set_color(self, color):
        pass

    def set_transparency(self, transparency):
        pass

    def set_custom_property(self, name, value):
        pass

    def create_multipoint3(self):
        pass

    def add_point(self, point):
        pass

    def geometry_parsing_finished(self):
        pass

    def create_vertex_property(self, name, type):
        pass

    def create_cell_property(self, name, type):
        pass

    def add_property_value(self, value):
        pass

    def property_parsing_finished(self):
        pass

Multilinestring

import GSTPy

class MultilinestringCallback(GSTPy.IParsingActions):
    def set_name(self, name):
        pass

    def set_color(self, color):
        pass

    def set_transparency(self, transparency):
        pass

    def set_custom_property(self, name, value):
        pass

    def create_multiline3(self):
        pass

    def add_point(self, point):
        pass

    def new_simplex(self):
        pass

    def geometry_parsing_finished(self):
        pass

    def create_vertex_property(self, name, type):
        pass

    def create_cell_property(self, name, type):
        pass

    def add_property_value(self, value):
        pass

    def property_parsing_finished(self):
        pass

Tin

import GSTPy

class TinCallback(GSTPy.IParsingActions):
    def set_name(self, name):
        pass

    def set_color(self, color):
        pass

    def set_transparency(self, transparency):
        pass

    def set_custom_property(self, name, value):
        pass

    def create_triangle_net3(self):
        pass

    def add_point(self, point):
        pass

    def add_triangle(self, triangle):
        pass

    def geometry_parsing_finished(self):
        pass

    def create_vertex_property(self, name, type):
        pass

    def create_cell_property(self, name, type):
        pass

    def add_property_value(self, value):
        pass

    def property_parsing_finished(self):
        pass

Tetrahderon Net

import GSTPy

class TetrahderonNetCallback(GSTPy.IParsingActions):
    def set_name(self, name):
        pass

    def set_color(self, color):
        pass

    def set_transparency(self, transparency):
        pass

    def set_custom_property(self, name, value):
        pass

    def create_tetrahedon_net3(self):
        pass

    def add_point(self, point):
        pass

    def add_tetrahedron(self, tetrahedron):
        pass

    def geometry_parsing_finished(self):
        pass

    def create_vertex_property(self, name, type):
        pass

    def create_cell_property(self, name, type):
        pass

    def add_property_value(self, value):
        pass

    def property_parsing_finished(self):
        pass

Example implementation

As a simple example lets implement a CSV file parser callback.

We want to list all points of a geometry with its vertex properties. We are only interested in the points, so lines, triangles and so on will be ignored.

csv_points_only.py

import GSTPy

class CsvCallback(GSTPy.IParsingActions):
    def __init__(self):

        super(CsvCallback, self).__init__()

        self.points = []
        self.property_names = []
        self.prop_values = []

    def add_point(self, point):
        self.points.append(point)

    def create_vertex_property(self, name, type):
        self.property_names.append(name)
        # type doesn't interest us here
        # the values are returned as strings anyways

    def add_property_value(self, value):
        self.prop_values.append(value)

    def get_csv_string(self):
        # make sure our property value count is as expected
        num_properties = len(self.property_names)
        num_points = len(self.points)
        assert len(self.prop_values) == num_properties * num_points
        # CSV header line
        tokens = ["x", "y", "z"]
        tokens.extend(self.property_names)
        csv = ",".join(tokens) + "\n"
        for i in xrange(num_points):
            # add the current point
            point = self.points[i]
            tokens = [str(point.x), str(point.y), str(point.z)]
            # add the property values for the current point
            prop_offset = i * num_properties
            tokens.extend(
                self.prop_values[prop_offset:prop_offset + num_properties])
            csv += ",".join(tokens) + "\n"
        return csv