PDF generation - Feather

WeasyPrint ships with the pdf extra. It converts HTML and CSS to PDF, letting you use familiar web technologies for document layout.

pip install "feather-framework[pdf]"

Basic usage

from io import BytesIO
from weasyprint import HTML

def generate_report(title, data):
    html_content = f"""
    <!DOCTYPE html>
    <html>
    <head>
        <style>
            body {{ font-family: sans-serif; margin: 40px; }}
            h1 {{ color: #1f2937; }}
            table {{ border-collapse: collapse; width: 100%; margin-top: 20px; }}
            td, th {{ border: 1px solid #d1d5db; padding: 8px; text-align: left; }}
            th {{ background-color: #f3f4f6; }}
        </style>
    </head>
    <body>
        <h1>{title}</h1>
        <table>
            <tr><th>Item</th></tr>
            {''.join(f'<tr><td>{row}</td></tr>' for row in data)}
        </table>
    </body>
    </html>
    """

    buffer = BytesIO()
    HTML(string=html_content).write_pdf(buffer)
    buffer.seek(0)
    return buffer

Render the HTML with a Jinja2 template instead of an f-string once the document grows past a few elements. You get the same escaping and partials as the rest of your views.

Saving to storage

from feather.storage import get_storage

@api.get('/reports/<id>/pdf')
@auth_required
def download_report(id):
    pdf_buffer = generate_report("Report", get_data(id))

    storage = get_storage()
    filename = f'reports/{id}.pdf'
    storage.upload(pdf_buffer, filename, content_type='application/pdf')

    url = storage.get_url(filename, expires_in=3600)
    return {'url': url}

Generating in the background

PDF rendering is slow enough to be worth moving off the request.

from feather import job

@job
def generate_report_async(report_id, user_id):
    pdf_buffer = generate_report("Report", get_data(report_id))
    storage = get_storage()
    filename = f'reports/{user_id}/{report_id}.pdf'
    storage.upload(pdf_buffer, filename, content_type='application/pdf')
    return {'filename': filename}

result = generate_report_async.enqueue(report_id, user_id)

⌘I