Filter filetype on open select dialog

Hi. Is it possible to filter file type with context.window_manager.fileselect_add(self)?
For example so the file diaog only show files that ends with .txt

I use a somewhat modified version of this to select the file, but I don’t want the dialog to show every file type. just the ones that ends with .something

<b>import</b> <b>bpy</b>


<b>class</b> <b>ExportSomeData</b>(bpy.types.Operator):
    <i>"""Test exporter which just writes hello world"""</i>
    bl_idname = "export.some_data"
    bl_label = "Export Some Data"

    filepath = bpy.props.StringProperty(subtype="FILE_PATH")

    <b>@classmethod</b>
    <b>def</b> poll(cls, context):
        <b>return</b> context.object <b>is</b> <b>not</b> None

    <b>def</b> execute(self, context):
        file = open(self.filepath, 'w')
        file.write("Hello World " + context.object.name)
        <b>return</b> {'FINISHED'}

    <b>def</b> invoke(self, context, event):
        context.window_manager.fileselect_add(self)
        <b>return</b> {'RUNNING_MODAL'}


<i># Only needed if you want to add into a dynamic menu</i>
<b>def</b> menu_func(self, context):
    self.layout.operator_context = 'INVOKE_DEFAULT'
    self.layout.operator(ExportSomeData.bl_idname, text="Text Export Operator")

<i># Register and add to the file selector</i>
bpy.utils.register_class(ExportSomeData)
bpy.types.INFO_MT_file_export.append(menu_func)


<i># test call</i>
bpy.ops.export.some_data('INVOKE_DEFAULT')

Thanks

the file import template shows how to filter .txt:

import bpy


def read_some_data(context, filepath, use_some_setting):
    print("running read_some_data...")
    f = open(filepath, 'r', encoding='utf-8')
    data = f.read()
    f.close()

    # would normally load the data here
    print(data)

    return {'FINISHED'}


# ImportHelper is a helper class, defines filename and
# invoke() function which calls the file selector.
from bpy_extras.io_utils import ImportHelper
from bpy.props import StringProperty, BoolProperty, EnumProperty
from bpy.types import Operator


class ImportSomeData(Operator, ImportHelper):
    """This appears in the tooltip of the operator and in the generated docs"""
    bl_idname = "import_test.some_data"  # important since its how bpy.ops.import_test.some_data is constructed
    bl_label = "Import Some Data"

    # ImportHelper mixin class uses this
    filename_ext = ".txt"

    filter_glob = StringProperty(
            default="*.txt",
            options={'HIDDEN'},
            )

    # List of operator properties, the attributes will be assigned
    # to the class instance from the operator settings before calling.
    use_setting = BoolProperty(
            name="Example Boolean",
            description="Example Tooltip",
            default=True,
            )

    type = EnumProperty(
            name="Example Enum",
            description="Choose between two items",
            items=(('OPT_A', "First Option", "Description one"),
                   ('OPT_B', "Second Option", "Description two")),
            default='OPT_A',
            )

    def execute(self, context):
        return read_some_data(context, self.filepath, self.use_setting)


# Only needed if you want to add into a dynamic menu
def menu_func_import(self, context):
    self.layout.operator(ImportSomeData.bl_idname, text="Text Import Operator")


def register():
    bpy.utils.register_class(ImportSomeData)
    bpy.types.INFO_MT_file_import.append(menu_func_import)


def unregister():
    bpy.utils.unregister_class(ImportSomeData)
    bpy.types.INFO_MT_file_import.remove(menu_func_import)


if __name__ == "__main__":
    register()

    # test call
    bpy.ops.import_test.some_data('INVOKE_DEFAULT')


filename_ext = “.txt” and
filter_glob = StringProperty(default="*.txt", …)
do the trick

Yes it does, nice. Thanks