PDF Generation

WeasyPrint is a powerful and easy-to-use library for generating PDFs from HTML and CSS in Django. It provides better styling control than reportlab and is well-suited for dynamic PDF generation (e.g., invoices, reports, and receipts).

Author

Benedict Thekkel

🚀 Step-by-Step Guide to Using WeasyPrint in Django

1️⃣ Install WeasyPrint

Before using WeasyPrint, install it using pip:

pip install weasyprint

WeasyPrint has some system dependencies. If you face installation issues, install the required system packages:

For Ubuntu/Debian:

sudo apt install libpango-1.0-0 libpangocairo-1.0-0 libcairo2 libffi-dev

For MacOS:

brew install pango cairo gdk-pixbuf

For Windows: - Install GTK+ from WeasyPrint’s documentation.

2️⃣ Create a Django View to Generate PDFs

We will create a class-based view (WeasyTemplateResponseMixin) to render a Django template into a PDF.

📌 Example: Generating a Simple PDF

# views.py
from django.http import HttpResponse
from django.template.loader import get_template
from weasyprint import HTML
import tempfile

def generate_pdf(request):
    """
    Generate a simple PDF from an HTML template.
    """
    template = get_template("pdf_template.html")
    context = {"title": "My PDF Report", "content": "This is a dynamically generated PDF."}
    html_content = template.render(context)

    # Create a temporary file
    with tempfile.NamedTemporaryFile(delete=True) as temp_file:
        HTML(string=html_content).write_pdf(temp_file.name)
        temp_file.seek(0)
        pdf_data = temp_file.read()

    response = HttpResponse(pdf_data, content_type="application/pdf")
    response["Content-Disposition"] = 'inline; filename="report.pdf"'
    return response

3️⃣ Create an HTML Template for the PDF

WeasyPrint renders HTML and CSS, so we need to define a well-structured HTML template.

📌 Example: `pdf_template.html`

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>{{ title }}</title>
    <style>
        body {
            font-family: Arial, sans-serif;
            margin: 20px;
        }
        h1 {
            color: #333;
        }
        .content {
            margin-top: 20px;
        }
    </style>
</head>
<body>
    <h1>{{ title }}</h1>
    <div class="content">
        <p>{{ content }}</p>
    </div>
</body>
</html>

4️⃣ Add URL Pattern

Map the PDF generation view in urls.py:

# urls.py
from django.urls import path
from .views import generate_pdf

urlpatterns = [
    path("generate-pdf/", generate_pdf, name="generate_pdf"),
]

Now, visiting /generate-pdf/ will return a dynamically generated PDF.

🖋️ Advanced WeasyPrint Usage

1️⃣ Generating PDFs with Django Querysets

You can pass database query results into the PDF template.

📌 Example: Generating a PDF Invoice

# views.py
from django.http import HttpResponse
from django.template.loader import render_to_string
from weasyprint import HTML
from .models import Order

def generate_invoice(request, order_id):
    """
    Generate an invoice PDF for a specific order.
    """
    order = Order.objects.get(id=order_id)
    context = {"order": order}
    html_string = render_to_string("invoice_template.html", context)

    pdf_file = HTML(string=html_string).write_pdf()
    response = HttpResponse(pdf_file, content_type="application/pdf")
    response["Content-Disposition"] = f'filename="invoice_{order.id}.pdf"'
    return response

📌 Example: `invoice_template.html`

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Invoice</title>
    <style>
        body {
            font-family: Arial, sans-serif;
            padding: 20px;
        }
        h1 {
            color: #333;
            border-bottom: 2px solid #000;
            padding-bottom: 10px;
        }
        table {
            width: 100%;
            border-collapse: collapse;
            margin-top: 20px;
        }
        th, td {
            border: 1px solid #ddd;
            padding: 10px;
            text-align: left;
        }
        .total {
            font-weight: bold;
            font-size: 1.2em;
        }
    </style>
</head>
<body>
    <h1>Invoice for Order #{{ order.id }}</h1>
    <p>Customer: {{ order.customer_name }}</p>
    <p>Date: {{ order.date }}</p>

    <table>
        <thead>
            <tr>
                <th>Product</th>
                <th>Quantity</th>
                <th>Price</th>
            </tr>
        </thead>
        <tbody>
            {% for item in order.items.all %}
            <tr>
                <td>{{ item.product_name }}</td>
                <td>{{ item.quantity }}</td>
                <td>${{ item.price }}</td>
            </tr>
            {% endfor %}
        </tbody>
    </table>

    <p class="total">Total Amount: ${{ order.total_price }}</p>
</body>
</html>

2️⃣ Saving PDFs to Django Models

You can store generated PDFs as files inside a Django model.

📌 Example: Save Invoice as a File

from django.core.files.base import ContentFile
from weasyprint import HTML
from .models import Order

def save_invoice_pdf(order_id):
    """
    Generate and save a PDF invoice to a model field.
    """
    order = Order.objects.get(id=order_id)
    html_string = render_to_string("invoice_template.html", {"order": order})
    
    pdf_file = HTML(string=html_string).write_pdf()
    
    # Save to model
    order.invoice.save(f"invoice_{order.id}.pdf", ContentFile(pdf_file), save=True)

📌 Update `Order` Model

from django.db import models

class Order(models.Model):
    customer_name = models.CharField(max_length=100)
    date = models.DateField(auto_now_add=True)
    total_price = models.DecimalField(max_digits=10, decimal_places=2)
    invoice = models.FileField(upload_to="invoices/", blank=True, null=True)  # Store PDF

🎨 Styling PDFs with CSS

WeasyPrint fully supports CSS, including: ✅ Fonts
✅ Page Breaks
✅ Headers & Footers
✅ Images

📌 Example: Adding Page Breaks

@page {
    size: A4;
    margin: 20mm;
}
.page-break {
    page-break-before: always;
}

📌 Usage in HTML

<p>Page 1 content</p>
<div class="page-break"></div>
<p>Page 2 content</p>

📌 Common WeasyPrint Issues & Fixes

Issue	Solution
`no such file or directory: cairo`	Install dependencies: `sudo apt install libcairo2`
`No module named weasyprint`	Run `pip install weasyprint`
Fonts not loading	Use absolute file paths for fonts (`file://` URLs)

✅ Summary: Key Takeaways

Feature	Django Implementation
✅ Generate PDFs	`HTML(string).write_pdf()`
✅ Use Templates	`render_to_string("template.html", context)`
✅ Save PDFs to Models	`order.invoice.save(...)`
✅ Style with CSS	Full CSS support, including `@page`

🚀 Now you can generate beautifully styled PDFs in Django using WeasyPrint! 🚀