backend/svg_processing.py

import re

# check: https://github.com/vasturiano/d3-zoomable/blob/master/example/svg/index.html

def remove_links_svg(svg):
    svg = svg.replace("</a>","")
    svg = svg.replace("\n\n","\n")
    regex = r"<a xlink[^>]*>"
    svg = re.sub(regex, "", svg, count=0, flags=re.MULTILINE)
    return svg

def resize_svg(svg, max_width=800):
    regex = r"<svg width=\"(?P<width>[\d]+)pt\" height=\"(?P<height>[\d]+)pt\""
    match = next(re.finditer(regex, svg, re.MULTILINE))
    width = int(match.group("width"))
    height = int(match.group("height"))
    if width <= max_width:
        return svg

    scale = max_width / width
    s_width = round(scale * width)
    s_height = round(scale * height)
    s_svg = svg.replace(match.group(), f'<svg width="{s_width}pt" height="{s_height}pt"')
    return s_svg

def postprocess_svg(svg):
    if not svg:
        return ""
    svg = "<svg" + svg.split("<svg", maxsplit=1)[1]
    svg = remove_links_svg(svg)
    svg = resize_svg(svg, max_width=800)
    return svg