Django - Did you forget to register or load this tag?

问题

I've created a custom tag that I want to use, but Django can't seem to find it. My templatetags directory is set up like this:

pygmentize.py

from pygments import highlight
from pygments.lexers import get_lexer_by_name
from django import template
from pygments.formatters.other import NullFormatter

register = template.Library()

@register.tag(name='code')
def do_code(parser,token):
    code = token.split_contents()[-1]
    nodelist = parser.parse(('endcode',))
    parser.delete_first_token()
    return CodeNode(code,nodelist)

class CodeNode(template.Node):
    def __init__(self,lang,code):
        self.lang = lang
        self.nodelist = code

    def render(self,context):
        code = self.nodelist.render(context)
        lexer = get_lexer_by_name('python')
        return highlight(code,lexer,NullFormatter())

I am trying to use this tag to render code in gameprofile.html.

gameprofile.html

(% load pygmentize %}
{% block content %}
    <title>{% block title %} | {{ game.title }}{% endblock %}</title>
    <div id="gamecodecontainer">
        {% code %}
            {{game.code}}
        {% endcode %}
    </div>
{% endblock content %}

When I navigate to gameprofile.html, I get an error:

Invalid block tag on line 23: 'code', expected 'endblock'. Did you forget to register or load this tag?

回答1:

did you try this

{% load games_tags %}

at the top instead of pygmentize?

回答2:

The error is in this line: (% load pygmentize %}, an invalid tag. Change it to {% load pygmentize %}

回答3:

I had the same problem, here's how I solved it. Following the first section of this very excellent Django tutorial, I did the following:

Create a new Django app by executing: python manage.py startapp new_app
Edit the settings.py file, adding the following to the list of INSTALLED_APPS: 'new_app',
Add a new module to the new_app package named new_app_tags.
In a Django HTML template, add the following to the top of the file, but after {% extends 'base_template_name.html' %}: {% load new_app_tags %}
In the new_app_tags module file, create a custom template tag (see below).
In the same Django HTML template, from step 4 above, use your shiney new custom tag like so: {% multiply_by_two | "5.0" %}
Celebrate!

Example from step 5 above:

from django import template

register = template.Library()

@register.simple_tag
def multiply_by_two(value):
    return float(value) * 2.0

回答4:

{% load static %}
<img src="{% static "my_app/example.jpg" %}" alt="My image">

in your templates, use the static template tag to build the URL for the given relative path using the configured STATICFILES_STORAGE.

回答5:

{% load static %}

Please add this template tag on top of the HTML or base HTML file

回答6:

For Django 2.2 + you have to load staticfiles in html template first before use static keyword

{% load staticfiles %}
<link rel="stylesheet" href="{% static 'css/bootstrap.min.css' %}">

Also you have to check that you defined STATIC_URL in setting.py

At last make sure the static files exist in defined folder

回答7:

The app that contains the custom tags must be in INSTALLED_APPS. So Are you sure that your directory is in INSTALLED_APPS ?

From the documentation:

The app that contains the custom tags must be in INSTALLED_APPS in order for the {% load %} tag to work. This is a security feature: It allows you to host Python code for many template libraries on a single host machine without enabling access to all of them for every Django installation.

回答8:

In gameprofile.html please change the tag {% endblock content %} to {% endblock %} then it works otherwise django will not load the endblock and give error.