seitime-frappe/frappe/utils/pdf.py
Ankush Menat 718b5b8bee
fix: Private images in PDFs from background jobs (#24980)
* refactor: Private images rendering in PDFs

Private images currently render fine if PDF is generated during a
request as we pass the cookiejar to WKHTML.

Background jobs however fail completeley because they can't retrieve
private images without cookiejar.

This PR converts all image types to base64 encoded sources in HTML
itself, so wkhtmltopdf doesn't have to a fire a request.

* test: private images in pdf
2024-02-21 10:38:02 +00:00

334 lines
8.7 KiB
Python

# Copyright (c) 2015, Frappe Technologies Pvt. Ltd. and Contributors
# License: MIT. See LICENSE
import base64
import contextlib
import io
import mimetypes
import os
import re
import subprocess
from urllib.parse import parse_qs, urlparse
import pdfkit
from bs4 import BeautifulSoup
from packaging.version import Version
from pypdf import PdfReader, PdfWriter
import frappe
from frappe import _
from frappe.core.doctype.file.utils import find_file_by_url
from frappe.utils import scrub_urls
from frappe.utils.jinja_globals import bundled_asset, is_rtl
PDF_CONTENT_ERRORS = [
"ContentNotFoundError",
"ContentOperationNotPermittedError",
"UnknownContentError",
"RemoteHostClosedError",
]
def pdf_header_html(soup, head, content, styles, html_id, css):
return frappe.render_template(
"templates/print_formats/pdf_header_footer.html",
{
"head": head,
"content": content,
"styles": styles,
"html_id": html_id,
"css": css,
"lang": frappe.local.lang,
"layout_direction": "rtl" if is_rtl() else "ltr",
},
)
def pdf_body_html(template, args, **kwargs):
try:
return template.render(args, filters={"len": len})
except Exception as e:
# Guess line number ?
frappe.throw(
_("Error in print format on line {0}: {1}").format(
_guess_template_error_line_number(template), e
),
exc=frappe.PrintFormatError,
title=_("Print Format Error"),
)
def _guess_template_error_line_number(template) -> int | None:
"""Guess line on which exception occurred from current traceback."""
with contextlib.suppress(Exception):
import sys
import traceback
_, _, tb = sys.exc_info()
for frame in reversed(traceback.extract_tb(tb)):
if template.filename in frame.filename:
return frame.lineno
def pdf_footer_html(soup, head, content, styles, html_id, css):
return pdf_header_html(soup=soup, head=head, content=content, styles=styles, html_id=html_id, css=css)
def get_pdf(html, options=None, output: PdfWriter | None = None):
html = scrub_urls(html)
html, options = prepare_options(html, options)
options.update({"disable-javascript": "", "disable-local-file-access": ""})
filedata = ""
if Version(get_wkhtmltopdf_version()) > Version("0.12.3"):
options.update({"disable-smart-shrinking": ""})
try:
# Set filename property to false, so no file is actually created
filedata = pdfkit.from_string(html, options=options or {}, verbose=True)
# create in-memory binary streams from filedata and create a PdfReader object
reader = PdfReader(io.BytesIO(filedata))
except OSError as e:
if any([error in str(e) for error in PDF_CONTENT_ERRORS]):
if not filedata:
print(html, options)
frappe.throw(_("PDF generation failed because of broken image links"))
# allow pdfs with missing images if file got created
if output:
output.append_pages_from_reader(reader)
else:
raise
finally:
cleanup(options)
if "password" in options:
password = options["password"]
if output:
output.append_pages_from_reader(reader)
return output
writer = PdfWriter()
writer.append_pages_from_reader(reader)
if "password" in options:
writer.encrypt(password)
filedata = get_file_data_from_writer(writer)
return filedata
def get_file_data_from_writer(writer_obj):
# https://docs.python.org/3/library/io.html
stream = io.BytesIO()
writer_obj.write(stream)
# Change the stream position to start of the stream
stream.seek(0)
# Read up to size bytes from the object and return them
return stream.read()
def prepare_options(html, options):
if not options:
options = {}
options.update(
{
"print-media-type": None,
"background": None,
"images": None,
"quiet": None,
# 'no-outline': None,
"encoding": "UTF-8",
# 'load-error-handling': 'ignore'
}
)
if not options.get("margin-right"):
options["margin-right"] = "15mm"
if not options.get("margin-left"):
options["margin-left"] = "15mm"
html, html_options = read_options_from_html(html)
options.update(html_options or {})
# cookies
options.update(get_cookie_options())
html = inline_private_images(html)
# page size
pdf_page_size = (
options.get("page-size") or frappe.db.get_single_value("Print Settings", "pdf_page_size") or "A4"
)
if pdf_page_size == "Custom":
options["page-height"] = options.get("page-height") or frappe.db.get_single_value(
"Print Settings", "pdf_page_height"
)
options["page-width"] = options.get("page-width") or frappe.db.get_single_value(
"Print Settings", "pdf_page_width"
)
else:
options["page-size"] = pdf_page_size
return html, options
def get_cookie_options():
options = {}
if frappe.session and frappe.session.sid and hasattr(frappe.local, "request"):
# Use wkhtmltopdf's cookie-jar feature to set cookies and restrict them to host domain
cookiejar = f"/tmp/{frappe.generate_hash()}.jar"
# Remove port from request.host
# https://werkzeug.palletsprojects.com/en/0.16.x/wrappers/#werkzeug.wrappers.BaseRequest.host
domain = frappe.utils.get_host_name().split(":", 1)[0]
with open(cookiejar, "w") as f:
f.write(f"sid={frappe.session.sid}; Domain={domain};\n")
options["cookie-jar"] = cookiejar
return options
def read_options_from_html(html):
options = {}
soup = BeautifulSoup(html, "html5lib")
options.update(prepare_header_footer(soup))
toggle_visible_pdf(soup)
# use regex instead of soup-parser
for attr in (
"margin-top",
"margin-bottom",
"margin-left",
"margin-right",
"page-size",
"header-spacing",
"orientation",
"page-width",
"page-height",
):
try:
pattern = re.compile(r"(\.print-format)([\S|\s][^}]*?)(" + str(attr) + r":)(.+)(mm;)")
match = pattern.findall(html)
if match:
options[attr] = str(match[-1][3]).strip()
except Exception:
pass
return str(soup), options
def inline_private_images(html) -> str:
soup = BeautifulSoup(html, "html.parser")
for img in soup.find_all("img"):
if b64 := _get_base64_image(img["src"]):
img["src"] = b64
return str(soup)
def _get_base64_image(src):
"""Return base64 version of image if user has permission to view it"""
try:
parsed_url = urlparse(src)
path = parsed_url.path
query = parse_qs(parsed_url.query)
mime_type = mimetypes.guess_type(path)[0]
if not mime_type.startswith("image/"):
return
filename = query.get("fid") and query["fid"][0] or None
file = find_file_by_url(path, name=filename)
if not file or not file.is_private:
return
b64_encoded_image = base64.b64encode(file.get_content()).decode()
return f"data:{mime_type};base64,{b64_encoded_image}"
except Exception:
frappe.logger("pdf").error("Failed to convert inline images to base64", exc_info=True)
def prepare_header_footer(soup: BeautifulSoup):
options = {}
head = soup.find("head").contents
styles = soup.find_all("style")
print_css = bundled_asset("print.bundle.css").lstrip("/")
css = frappe.read_file(os.path.join(frappe.local.sites_path, print_css))
# extract header and footer
for html_id in ("header-html", "footer-html"):
if content := soup.find(id=html_id):
content = content.extract()
# `header/footer-html` are extracted, rendered as html
# and passed in wkhtmltopdf options (as '--header/footer-html')
# Remove instances of them from main content for render_template
for tag in soup.find_all(id=html_id):
tag.extract()
toggle_visible_pdf(content)
id_map = {"header-html": "pdf_header_html", "footer-html": "pdf_footer_html"}
hook_func = frappe.get_hooks(id_map.get(html_id))
html = frappe.get_attr(hook_func[-1])(
soup=soup,
head=head,
content=content,
styles=styles,
html_id=html_id,
css=css,
)
# create temp file
fname = os.path.join("/tmp", f"frappe-pdf-{frappe.generate_hash()}.html")
with open(fname, "wb") as f:
f.write(html.encode("utf-8"))
# {"header-html": "/tmp/frappe-pdf-random.html"}
options[html_id] = fname
else:
if html_id == "header-html":
options["margin-top"] = "15mm"
elif html_id == "footer-html":
options["margin-bottom"] = "15mm"
return options
def cleanup(options):
for key in ("header-html", "footer-html", "cookie-jar"):
if options.get(key) and os.path.exists(options[key]):
os.remove(options[key])
def toggle_visible_pdf(soup):
for tag in soup.find_all(attrs={"class": "visible-pdf"}):
# remove visible-pdf class to unhide
tag.attrs["class"].remove("visible-pdf")
for tag in soup.find_all(attrs={"class": "hidden-pdf"}):
# remove tag from html
tag.extract()
def get_wkhtmltopdf_version():
wkhtmltopdf_version = frappe.cache.hget("wkhtmltopdf_version", None)
if not wkhtmltopdf_version:
try:
res = subprocess.check_output(["wkhtmltopdf", "--version"])
wkhtmltopdf_version = res.decode("utf-8").split(" ")[1]
frappe.cache.hset("wkhtmltopdf_version", None, wkhtmltopdf_version)
except Exception:
pass
return wkhtmltopdf_version or "0"