mirror of
https://github.com/open-webui/open-webui.git
synced 2025-12-11 20:05:19 +00:00
173 lines
6.3 KiB
Python
173 lines
6.3 KiB
Python
from datetime import datetime
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from io import BytesIO
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from pathlib import Path
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from typing import Dict, Any, List
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from markdown import markdown
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from xhtml2pdf import pisa
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import site
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from fpdf import FPDF
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from open_webui.env import STATIC_DIR, FONTS_DIR
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from open_webui.apps.webui.models.chats import ChatTitleMessagesForm
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class PDFGenerator:
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"""
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Description:
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The `PDFGenerator` class is designed to create PDF documents from chat messages.
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The process involves transforming markdown content into HTML and then into a PDF format,
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which can be easily returned as a response to the routes.
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It depends on xhtml2pdf for converting HTML to PDF (more details at https://github.com/xhtml2pdf/xhtml2pdf).
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I found xhtml2pdf issues when rendering list html tag, see https://github.com/xhtml2pdf/xhtml2pdf/issues/550
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and https://github.com/xhtml2pdf/xhtml2pdf/issues/756.
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Attributes:
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- `form_data`: An instance of `ChatTitleMessagesForm` containing title and messages.
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"""
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def __init__(self, form_data: ChatTitleMessagesForm):
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self.html_body = None
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self.messages_html = None
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self.form_data = form_data
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self.css = Path(STATIC_DIR / "assets" / "pdf-style.css").read_text()
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def format_timestamp(self, timestamp: float) -> str:
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"""Convert a UNIX timestamp to a formatted date string."""
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try:
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date_time = datetime.fromtimestamp(timestamp)
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return date_time.strftime("%Y-%m-%d, %H:%M:%S")
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except (ValueError, TypeError) as e:
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# Log the error if necessary
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return ""
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def _build_html_message(self, message: Dict[str, Any]) -> str:
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"""Build HTML for a single message."""
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role = message.get("role", "user")
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content = message.get("content", "")
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timestamp = message.get("timestamp")
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model = message.get("model") if role == "assistant" else ""
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date_str = self.format_timestamp(timestamp) if timestamp else ""
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# extends pymdownx extension to convert markdown to html.
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# - https://facelessuser.github.io/pymdown-extensions/usage_notes/
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html_content = markdown(content, extensions=["pymdownx.extra"])
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html_message = f"""
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<div class="message">
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<small> {date_str} </small>
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<div>
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<h2>
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<strong>{role.title()}</strong>
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<small class="text-muted">{model}</small>
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</h2>
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</div>
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<div class="markdown-section">
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{html_content}
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</div>
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</div>
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"""
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return html_message
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def _fetch_resources(self, uri: str, rel: str) -> str:
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print(str(STATIC_DIR / uri))
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return str(STATIC_DIR / uri)
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def _create_pdf_from_html(self) -> bytes:
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"""Convert HTML content to PDF and return the bytes."""
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pdf_buffer = BytesIO()
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pisa_status = pisa.CreatePDF(
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src=self.html_body.encode("UTF-8"),
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dest=pdf_buffer,
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encoding="UTF-8",
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link_callback=self._fetch_resources,
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)
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if pisa_status.err:
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raise RuntimeError("Error generating PDF")
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return pdf_buffer.getvalue()
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def _generate_html_body(self) -> str:
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"""Generate the full HTML body for the PDF."""
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return f"""
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<html>
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<head>
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<meta charset="UTF-8">
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<meta name="viewport" content="width=device-width, initial-scale=1.0">
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<style type="text/css">
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{self.css}
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</style>
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</head>
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<body>
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<div class="container">
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<div class="text-center">
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<h1>{self.form_data.title}</h1>
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</div>
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<div>
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{self.messages_html}
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</div>
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</div>
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</body>
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</html>
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"""
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def generate_chat_pdf(self) -> bytes:
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"""
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Generate a PDF from chat messages.
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"""
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try:
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global FONTS_DIR
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pdf = FPDF()
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pdf.add_page()
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# When running using `pip install` the static directory is in the site packages.
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if not FONTS_DIR.exists():
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FONTS_DIR = Path(site.getsitepackages()[0]) / "static/fonts"
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# When running using `pip install -e .` the static directory is in the site packages.
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# This path only works if `open-webui serve` is run from the root of this project.
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if not FONTS_DIR.exists():
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FONTS_DIR = Path("./backend/static/fonts")
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pdf.add_font("NotoSans", "", f"{FONTS_DIR}/NotoSans-Regular.ttf")
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pdf.add_font("NotoSans", "b", f"{FONTS_DIR}/NotoSans-Bold.ttf")
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pdf.add_font("NotoSans", "i", f"{FONTS_DIR}/NotoSans-Italic.ttf")
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pdf.add_font("NotoSansKR", "", f"{FONTS_DIR}/NotoSansKR-Regular.ttf")
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pdf.add_font("NotoSansJP", "", f"{FONTS_DIR}/NotoSansJP-Regular.ttf")
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pdf.add_font("NotoSansSC", "", f"{FONTS_DIR}/NotoSansSC-Regular.ttf")
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pdf.set_font("NotoSans", size=12)
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pdf.set_fallback_fonts(["NotoSansKR", "NotoSansJP", "NotoSansSC"])
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pdf.set_auto_page_break(auto=True, margin=15)
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# Adjust the effective page width for multi_cell
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effective_page_width = (
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pdf.w - 2 * pdf.l_margin - 10
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) # Subtracted an additional 10 for extra padding
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# Add chat messages
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for message in self.form_data.messages:
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role = message["role"]
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content = message["content"]
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pdf.set_font("NotoSans", "B", size=14) # Bold for the role
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pdf.multi_cell(effective_page_width, 10, f"{role.upper()}", 0, "L")
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pdf.ln(1) # Extra space between messages
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pdf.set_font("NotoSans", size=10) # Regular for content
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pdf.multi_cell(effective_page_width, 6, content, 0, "L")
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pdf.ln(1.5) # Extra space between messages
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# Save the pdf with name .pdf
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pdf_bytes = pdf.output()
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return bytes(pdf_bytes)
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except Exception as e:
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raise e
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