is_subsetting_needed property

FontSavingArgs.is_subsetting_needed property

Allows to specify whether the current font will be subsetted before exporting as a font resource.

@property
def is_subsetting_needed(self) -> bool:
    ...

@is_subsetting_needed.setter
def is_subsetting_needed(self, value: bool):
    ...

Remarks

Fonts can be exported as complete original font files or subsetted to include only the characters that are used in the document. Subsetting allows to reduce the resulting font resource size.

By default, Aspose.Words decides whether to perform subsetting or not by comparing the original font file size with the one specified in HtmlSaveOptions.font_resources_subsetting_size_threshold. You can override this behavior for individual fonts by setting the FontSavingArgs.is_subsetting_needed property.

Examples

Shows how to define custom logic for exporting fonts when saving to HTML.

def handle_font_saving(self, args):
    # Custom logic: export font to file in ARTIFACTS_DIR
    # args is FontSavingArgs
    if args.is_export_needed:
        font_file_name = args.font_file_name
        if not font_file_name:
            font_file_name = args.font_family_name + '.ttf'
        font_path = Path(ARTIFACTS_DIR) / font_file_name
        with open(font_path, 'wb') as f:
            # args.font_stream is a stream object (io.BytesIO-like)
            f.write(args.font_stream.read())
        # Optional: args.keep_font_stream_open = True if needed later
        args.keep_font_stream_open = False

def export_fonts_to_separate_files(self):
    doc = aw.Document(MY_DIR + 'Rendering.docx')
    options = aw.saving.HtmlSaveOptions()
    options.export_font_resources = True
    options.font_saving_callback = self.handle_font_saving
    # The callback will export .ttf files and save them alongside the output document.
    doc.save(ARTIFACTS_DIR + 'HtmlSaveOptions.SaveExportedFonts.html', save_options=options)
    for font_filename in [str(f) for f in Path(ARTIFACTS_DIR).iterdir() if f.suffix == '.ttf']:
        print(font_filename)

Shows how to define custom logic for exporting fonts when saving to HTML (HandleFontSaving).

class HandleFontSaving(aw.saving.IFontSavingCallback):

    def font_saving(self, args):
        from pathlib import Path
        from api_example_base import ApiExampleBase, MY_DIR, ARTIFACTS_DIR, GOLDS_DIR, TEMP_DIR, IMAGE_DIR, FONTS_DIR
        print(f'Font:\t{args.font_family_name}')
        if args.bold:
            print(', bold')
        if args.italic:
            print(', italic')
        print(f'\nSource:\t{args.original_file_name}, {args.original_file_size} bytes\n')
        # We can also access the source document from here.
        self.assertTrue(args.document.original_file_name.endswith('Rendering.docx'))
        self.assertTrue(args.is_export_needed)
        self.assertTrue(args.is_subsetting_needed)
        # There are two ways of saving an exported font.
        # 1 -  Save it to a local file system location:
        args.font_file_name = Path(args.original_file_name).name
        # 2 -  Save it to a stream:
        args.font_stream = open(Path(ARTIFACTS_DIR) / Path(args.original_file_name).name, 'wb')
        self.assertFalse(args.keep_font_stream_open)

See Also

FontSavingArgs.is_export_needed property FontSavingArgs.italic property