Shubham Ankit

Shubham Ankit

1570243551

How to Create PDF Documents with Django in 2019

If you've read my Web Development with Django Cookbook, you might remember a recipe for creating PDF documents using Pisa xhtml2pdf. Well, this library does its job, but it supports only a subset of HTML and CSS features. For example, for multi-column layouts, you have to use tables, like it's 1994.

I needed some fresh and flexible option to generate donation receipts for the donation platform www.make-impact.org and reports for the strategic planner 1st things 1st I have been building. After a quick research I found another much more suitable library. It's called WeasyPrint. In this article, I will tell you how to use it with Django and what's valuable in it.

Features

WeasyPrint uses HTML and CSS 2.1 to create pixel-perfect, or let's rather say point-perfect, PDF documents. WeasyPrint doesn't use WebKit or Gecko but has its own rendering engine. As a proof that it works correctly, it passes the famous among web developers Acid2 test which was created back in the days before HTML5 to check how compatible browsers are with CSS 2 standards.

All supported features (and unsupported exceptions) are listed in the documentation. But my absolute favorites are these:

  • Layouts with floated elements. You don't have to use tables anymore if you want to have the recipient address on the left side and the sender information on the right side in a letter, or if you want to have the main content and the side notes in an exercise book. Just use floated elements.
  • Working links. The generated document can have clickable links to external URLs and internal anchors. You can straightforwardly create a clickable table of contents or a banner that leads back to your website.
  • Support for web fonts. With the wide variety of embeddable web fonts, your documents don't need to look boring anymore. Why not write titles in elegant cursive or in bold western letters?
  • Background images. By default, when you print an HTML page, all foreground images get printed, but the backgrounds are skipped. When you generate a PDF document for printing, you can show background images anywhere, even in the margins of the printed page.
  • SVG kept as vector images. When you have diagrams and graphics in a PDF document, you usually want to preserve the quality of the lines. Even if they look good on the screen, raster images might be not what you want, because on a printed page the resolution will differ and the quality can be lost. WeasyPrint keeps SVG images as vector images, so you have the highest possible quality in the prints.

Important Notes

WeasyPrint needs Python 3.4 or newer. That's great for new Django projects, but might be an obstacle if you want to integrate it into an existing website running on Python 2.7. Can it be the main argumentation for you to upgrade your old Django projects to the new Python version?

WeasyPrint is dependent on several OS libraries: Pango, GdkPixbuf, Cairo, and Libffi. In the documentation, there are understandable one-line instructions how to install them on different operating systems. You can have a problem only if you don't have full control of the server where you are going to deploy your project.

If you need some basic headers and footers for all pages, you can use @pageCSS selector for that. If you need extended headers and footers for each page, it's best to combine the PDF document out of separate HTML documents for each page. Examples follow below.

The fun fact, Emojis are drawn using some weird raster single-color font. I don't recommend using them in your PDFs unless you replace them with SVG images.

Show Me the Code

A technical article is always more valuable when it has some quick code snippets to copy and paste. Here you go!

Simple PDF View

This snippet generates a donation receipt and shows it directly in the browser. Should the PDF be downloadable immediately, change content disposition from inline to attachment.

# -*- coding: UTF-8 -*-
from __future__ import unicode_literals

from django.http import HttpResponse
from django.template.loader import render_to_string
from django.utils.text import slugify
from django.contrib.auth.decorators import login_required

from weasyprint import HTML
from weasyprint.fonts import FontConfiguration

from .models import Donation

@login_required
def donation_receipt(request, donation_id):
donation = get_object_or_404(Donation, pk=donation_id, user=request.user)
response = HttpResponse(content_type=“application/pdf”)
response[‘Content-Disposition’] = “inline; filename={date}-{name}-donation-receipt.pdf”.format(
date=donation.created.strftime(‘%Y-%m-%d’),
name=slugify(donation.donor_name),
)
html = render_to_string(“donations/receipt_pdf.html”, {
‘donation’: donation,
})

font_config = FontConfiguration()
HTML(string=html).write_pdf(response, font_config=font_config)
return response

Page Configuration Using CSS

Your PDF document can have a footer with an image and text on every page, using background-image and content properties:

{% load staticfiles i18n %}
<link href=“https://fonts.googleapis.com/css?family=Playfair+Display:400,400i,700,700i,900” rel=“stylesheet” />
<style>
@page {
size: “A4”;
margin: 2.5cm 1.5cm 3.5cm 1.5cm;
@bottom-center {
background: url({% static ‘site/img/logo-pdf.svg’ %}) no-repeat center top;
background-size: auto 1.5cm;
padding-top: 1.8cm;
content: “{% trans “Donation made via www.make-impact.org” %}”;
font: 10pt “Playfair Display”;
text-align: center;
vertical-align: top;
}
}
</style>

Pagination

You can show page numbers in the footer using CSS as follows.

@page {
margin: 3cm 2cm;
@top-center {
content: “Documentation”;
}
@bottom-right {
content: “Page " counter(page) " of " counter(pages);
}
}

Horizontal Page Layout

You can rotate the page to horizontal layout with size: landscape.

@page {
size: landscape;
}

HTML-based Footer

Another option to show an image and text in the header or footer on every page is to use an HTML element with position: fixed. This way you have more flexibility about formatting, but the element on all your pages will have the same content.

<style>
footer {
position: fixed;
bottom: -2.5cm;
width: 100%;
text-align: center;
font-size: 10pt;
}
footer img {
height: 1.5cm;
}
</style>
<footer>
{% with website_url=“https://www.make-impact.org” %}
<a href=”{{ website_url }}“>
<img alt=”" src=“{% static ‘site/img/logo-contoured.svg’ %}” />
</a><br />
{% blocktrans %}Donation made via <a href=“{{ website_url }}”>www.make-impact.org</a>{% endblocktrans %}
{% endwith %}
</footer>

Document Rendering from Page to Page

When you need to have a document with complex unique headers and footers, it is best to render each page as a separate HTML document and then to combine them into one. This is how to do that:

def letter_pdf(request, letter_id):
letter = get_object_or_404(Letter, pk=letter_id)
response = HttpResponse(content_type=‘application/pdf’)
response[‘Content-Disposition’] = (
‘inline; ’
f’filename={letter.created:%Y-%m-%d}-letter.pdf’
)
COMPONENTS = [
‘letters/pdf/cover.html’,
‘letters/pdf/page01.html’,
‘letters/pdf/page02.html’,
‘letters/pdf/page03.html’,
]
documents = []
font_config = FontConfiguration()
for template_name in COMPONENTS:
html = render_to_string(template_name, {
‘letter’: letter,
})
document = HTML(string=html).render(font_config=font_config)
documents.append(document)

all_pages = [page for document in documents for page in document.pages]
documents[0].copy(all_pages).write_pdf(response)

return response

Final Thoughts

I believe that WeasyPrint could be used not only for invoices, tickets, or booking confirmations but also for online magazines and small booklets. If you want to see PDF rendering with WeasyPrint in action, make a donation to your chosen organization at www.make-impact.org (when it’s ready) and download the donation receipt. Or check the demo account at my.1st-things-1st.com and find the button to download the results of a prioritization project as PDF document.


Cover photo by Daniel Korpai.

#django #python

What is GEEK

Buddha Community

Ahebwe  Oscar

Ahebwe Oscar

1620177818

Django admin full Customization step by step

Welcome to my blog , hey everyone in this article you learn how to customize the Django app and view in the article you will know how to register  and unregister  models from the admin view how to add filtering how to add a custom input field, and a button that triggers an action on all objects and even how to change the look of your app and page using the Django suit package let’s get started.

Database

Custom Titles of Django Admin

Exclude in Django Admin

Fields in Django Admin

#django #create super user django #customize django admin dashboard #django admin #django admin custom field display #django admin customization #django admin full customization #django admin interface #django admin register all models #django customization

August  Larson

August Larson

1624428000

Creating PDF Invoices in Python with pText

Introduction

The Portable Document Format (PDF) is not a WYSIWYG (What You See is What You Get) format. It was developed to be platform-agnostic, independent of the underlying operating system and rendering engines.

To achieve this, PDF was constructed to be interacted with via something more like a programming language, and relies on a series of instructions and operations to achieve a result. In fact, PDF is based on a scripting language - PostScript, which was the first device-independent Page Description Language.

In this guide, we’ll be using pText - a Python library dedicated to reading, manipulating and generating PDF documents. It offers both a low-level model (allowing you access to the exact coordinates and layout if you choose to use those) and a high-level model (where you can delegate the precise calculations of margins, positions, etc to a layout manager).

We’ll take a look at how to create a PDF invoice in Python using pText.

#python #pdf #creating pdf invoices in python with ptext #creating pdf invoices #pdf invoice #creating pdf invoices in python with ptext

Ahebwe  Oscar

Ahebwe Oscar

1620185280

How model queries work in Django

How model queries work in Django

Welcome to my blog, hey everyone in this article we are going to be working with queries in Django so for any web app that you build your going to want to write a query so you can retrieve information from your database so in this article I’ll be showing you all the different ways that you can write queries and it should cover about 90% of the cases that you’ll have when you’re writing your code the other 10% depend on your specific use case you may have to get more complicated but for the most part what I cover in this article should be able to help you so let’s start with the model that I have I’ve already created it.

**Read More : **How to make Chatbot in Python.

Read More : Django Admin Full Customization step by step

let’s just get into this diagram that I made so in here:

django queries aboutDescribe each parameter in Django querset

we’re making a simple query for the myModel table so we want to pull out all the information in the database so we have this variable which is gonna hold a return value and we have our myModel models so this is simply the myModel model name so whatever you named your model just make sure you specify that and we’re gonna access the objects attribute once we get that object’s attribute we can simply use the all method and this will return all the information in the database so we’re gonna start with all and then we will go into getting single items filtering that data and go to our command prompt.

Here and we’ll actually start making our queries from here to do this let’s just go ahead and run** Python manage.py shell** and I am in my project file so make sure you’re in there when you start and what this does is it gives us an interactive shell to actually start working with our data so this is a lot like the Python shell but because we did manage.py it allows us to do things a Django way and actually query our database now open up the command prompt and let’s go ahead and start making our first queries.

#django #django model queries #django orm #django queries #django query #model django query #model query #query with django

Cayla  Erdman

Cayla Erdman

1594369800

Introduction to Structured Query Language SQL pdf

SQL stands for Structured Query Language. SQL is a scripting language expected to store, control, and inquiry information put away in social databases. The main manifestation of SQL showed up in 1974, when a gathering in IBM built up the principal model of a social database. The primary business social database was discharged by Relational Software later turning out to be Oracle.

Models for SQL exist. In any case, the SQL that can be utilized on every last one of the major RDBMS today is in various flavors. This is because of two reasons:

1. The SQL order standard is genuinely intricate, and it isn’t handy to actualize the whole standard.

2. Every database seller needs an approach to separate its item from others.

Right now, contrasts are noted where fitting.

#programming books #beginning sql pdf #commands sql #download free sql full book pdf #introduction to sql pdf #introduction to sql ppt #introduction to sql #practical sql pdf #sql commands pdf with examples free download #sql commands #sql free bool download #sql guide #sql language #sql pdf #sql ppt #sql programming language #sql tutorial for beginners #sql tutorial pdf #sql #structured query language pdf #structured query language ppt #structured query language

How to create a Django project and a Django application

To start off create a new folder for the Django project and move into it
Here I called django-quick-start the main folder that will hold the project. Pay attention, this is not the actual Django project, but just its “home”. Once inside the new folder create a Python virtual environment and activate it (note, these are two distinct commands)
Pay attention again: django_quick_start now is the actual Django project created inside the django-quick-start folder. The name of this home folder doesn’t matter, but Django projects cannot have dashes in the name. That’s the reason for these underscores in django_quick_start.
Pay also attention to the dot in django-admin startproject django_quick_start … With the dot we can avoid additional folder nesting.

#django #django application #create a django