python django: python django (django template language 2)

Django Template Language

Tags

for

The for loop over each item in an array for example to display a list of athletes provided in athlete_list:

<ul>
{%for athlete in athlete_list%}
<li>{{athlete.name}}</li>
{%endfor%}
</ul>

if ,elif,and else

Evaluates a variable and if that variable is true the contents of the block are displayed

{% if athlete_list %}
    Number of athletes: {{ athlete_list|length }}
{% elif athlete_in_locker_room_list %}
    Athletes should be out of the locker room soon!
{% else %}
    No athletes.
{% endif %}

in the above if athlete_list is not empty the number of athletes will be displayed by the {{athlete_list|length}} variable . Otherwise if athlete_in_locker_room_list is not empty the message "Athletes should be out..." will be displayed if both lists are empty "No athletes " will be displayed
you can also use filters and various operators in the if tag:

{% if athlete_list|length > 1 %}
   Team: {% for athlete in athlete_list %} ... {% endfor %}
{% else %}
   Athlete: {{ athlete_list.0.name }}
{% endif %}

most templates will return string so mathematical comparisons using filters will generally not work as you expect Length is an exception

Comments

the comment out part of a line in a template use the comment syntax{# #} for example this template would render as 'hello':

{#greeting#}hello

a comment can contain any template code invalid or not For example

{# {% if foo %}bar{% else %} #}

This syntax can only be used for single-line comments (no newlines are permitted between the {# and #} delimiters). If you need to comment out a multiline portion of the template, see the comment tag.

Template inheritance

The most powerful and thus the most complex - part of djangos template engine is template inheritance . template inheritance allow you to build a base skeleton template that contains all the common elements of your site and defines block that child templates can override

Comments

The method to comment out part of a line in a template we can use {# #}
by using this we can comment out for example

{#hello#}greetings

The template would render as 'greeting' a comment can contain any code invalid or not for example

{# {% if foo %}bar{% else %} #}

This syntax can only be used for single line comments (no newlines are permitted between the {#and#} delimiters ) its used only for single line comments but to comment out multiline line comment we use {%comment%}and{%endcomment%} an optional note can be inserted in the first tag this is useful when commenting out code for documentint why the code was disabled .

<p>Rendered text with {{ pub_date|date:"c" }}</p>
{% comment "Optional note" %}
    <p>Commented out text with {{ create_date|date:"c" }}</p>
{% endcomment %}

comment tags cannot be nested

Template inheritance

as inheritance in other languages the template inheritance allows us to build a base skeleton template that contains all the common elements of our site and defines blocks that child templates can override
its easiest to understand template inheritance y starting with an example

<!DOCTYPE html>
<html lang="en">
<head>
    <link rel="stylesheet" href="style.css">
    <title>{% block title %}My amazing site{% endblock %}</title>
</head>

<body>
    <div id="sidebar">
        {% block sidebar %}
        <ul>
            <li><a href="/">Home</a></li>
            <li><a href="/blog/">Blog</a></li>
        </ul>
        {% endblock %}
    </div>

    <div id="content">
        {% block content %}{% endblock %}
    </div>
</body>
</html>

this template will be our base class which is base.html its a simple html skeleton document that you might use for a simple two coloumn page its the job of child templates to fill the empty blocks with content
In this example the block tag defines three blocks that child templates can fill in all the block tag does is to tell the template engine that a child template may override those portions of the template
A child template might look like this :

{% extends "base.html" %}

{% block title %}My amazing blog{% endblock %}

{% block content %}
{% for entry in blog_entries %}
<br />
<h2>
{{ entry.title }}</h2>
{{ entry.body }}<br />
{% endfor %}
{% endblock %}

More on template inheritance and django template language will be included in next pages till then thanks for reading this blog and kindly expecting your feed backs please reply on comment section and follow let me know your suggestions and follow me and share this blog

python django

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Wednesday, September 26, 2018

python django (django template language 2)

Comments

Template inheritance

More on template inheritance and django template language will be included in next pages till then thanks for reading this blog and kindly expecting your feed backs please reply on comment section and follow let me know your suggestions and follow me and share this blog

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