def _generate_diagram(app, diagram_type, output_format, source):
try:
output_format = output_format.lower()
if output_format == 'png':
result = generate_diag(app, diagram_type, output_format, source)
response = send_file(io.BytesIO(result),
attachment_filename='result.png',
mimetype='image/png')
return response
elif output_format == 'pdf':
result = generate_diag(app, diagram_type, output_format, source)
response = make_response(result)
response.headers['Content-Type'] = 'application/pdf'
response.headers['Content-Disposition'] = 'inline; filename=result.pdf'
return response
elif output_format == 'svg':
result = generate_diag(app, diagram_type, output_format, source)
response = make_response(result)
response.headers["Content-Type"] = "image/svg+xml; charset=utf-8"
return response
else:
raise InvalidUsage('Unsupported output format: %s. Must be one of: png, svg or pdf.' % output_format,
status_code=400)
except GenerateError as err:
raise err
except Exception as err:
raise GenerateError('Unexpected error',
status_code=500,
payload={
'source': source,
'output_format': output_format,
'diagram_type': diagram_type,
'error': str(err)
})
def generate_diag(app, diagram_type, output_format, source):
options = ['-T' + output_format, 'file']
app.parse_options(options)
output_format = output_format.lower()
if output_format == 'pdf':
app.options.font = [
'/usr/share/fonts/truetype/dejavu/DejaVuSerif.ttf',
'/usr/share/fonts/ttf-dejavu/DejaVuSerif.ttf'
]
app.fontmap = create_fontmap(app.options)
app.setup()
app.code = source
try:
tree = app.module.parser.parse_string(app.code)
try:
diagram = app.module.builder.ScreenNodeBuilder.build(
tree, app.options)
except TypeError:
diagram = app.module.builder.ScreenNodeBuilder.build(
tree) # old interface
drawer = app.module.drawer.DiagramDraw(
app.options.type,
diagram,
None,
fontmap=app.fontmap,
code=app.code,
antialias=app.options.antialias,
nodoctype=app.options.nodoctype,
transparency=app.options.transparency)
drawer.draw()
drawer.drawer._run()
if output_format == 'png':
png_image = drawer.drawer.save(None, None, drawer.format)
return png_image
elif output_format == 'pdf':
pdf_drawer = drawer.drawer.target
pdf_drawer.canvas.showPage()
binary_pdf = pdf_drawer.canvas.getpdfdata()
return binary_pdf
elif output_format == 'svg':
xml_text = drawer.drawer.save(None, None, drawer.format)
return xml_text
except (ParseException, Exception) as err:
raise GenerateError('Unable to generate the ' + diagram_type +
' diagram from source',
status_code=400,
payload={
'source': source,
'output_format': output_format,
'diagram_type': diagram_type,
'error': str(err)
})