Django - Template System Django makes it possible to separate python and HTML, the python goes in views and HTML goes in templates.
The Render Function
This function takes three parameters −
Request − The initial request.
The path to the template − This is the path relative to the TEMPLATE_DIRS option in the project settings.py variables.
Dictionary of parameters − A dictionary that contains all variables needed in the template. This variable can be created or you can use locals() to pass all local variable declared in the view.
Displaying Variables
A variable looks like this: {{variable}}. The template replaces the variable by the variable sent by the view in the third parameter of the render function.
hello.html
Hello World!!!Today is {{today}}
Then our view will change to −
def hello(request):
from django.shortcuts import render
from django.http import HttpResponse
from datetime import datetime
def index(request):
return render(request, "index.html", {})
def hello(request):
myDate = datetime.now()
#formatedDate = myDate.strftime("%Y-%m-%d %H:%M:%S")
#today = myDate.strftime("%A")
today = myDate.strftime("%a")
daysOfWeek = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
return render(request, "hello.html", {"today" : today, "days_of_week" : daysOfWeek})
#return render(request, "hello.html", {"today" : today})
We will now get the following output after accessing the URL/myapp/hello −Hello World!!!
Today is Sept. 11, 2016
Tag if
Just like in Python you can use if, else and elif in your template −
<html>
<body>
Hello World!!!<p>Today is {{today}}</p>
We are
{% if today == 'Sun' %}
the Sunday day of month.
{% elif today == 30 %}
the last day of month.
{% else %}
I don't know.
{%endif%}
</body>
</html>
In this new template, depending on the date of the day, the template will render a certain value.Tag for
Just like 'if', we have the 'for' tag, that works exactly like in Python. Let's change our hello view to transmit a list to our template −
def hello(request):
today = datetime.datetime.now().date()
daysOfWeek = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
return render(request, "hello.html", {"today" : today, "days_of_week" : daysOfWeek})
The template to display that list using {{ for }} −
<html>
<body>
Hello World!!!<p>Today is {{today}}</p>
We are
{% if today.day == 1 %}
the first day of month.
{% elif today == 30 %}
the last day of month.
{% else %}
I don't know.
{%endif%}
<p>
{% for day in days_of_week %}
{{day}}
</p>
{% endfor %}
</body>
</html>
And we should get something like −Hello World!!!
Today is Sept. 11, 2015
We are I don't know.
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Block and Extend Tags
A template system cannot be complete without template inheritance. Meaning when you are designing your templates, you should have a main template with holes that the child's template will fill according to his own need, like a page might need a special css for the selected tab.
Let’s change the hello.html template to inherit from a main_template.html.
main_template.html
<html>
<head>
<title>
{% block title %}Page Title{% endblock %}
</title>
</head>
<body>
{% block content %}
Body content
{% endblock %}
</body>
</html>
hello.html
{% extends "main_template.html" %}
{% block title %}My Hello Page{% endblock %}
{% block content %}
Hello World!!!Today is {{today}}
We are
{% if today.day == 1 %}
the first day of month.
{% elif today == 30 %}
the last day of month.
{% else %}
I don't know.
{%endif%}
{% for day in days_of_week %}
{{day}}
{% endfor %}
{% endblock %}
