How to add custom(or Dynamic) Javascript from Django Backend? - javascript

I want to add custom JavaScript everytime as per the logic in my backend.
For example:
--views.py--
...
js="JavaScript which i want to add"
js_={'js_script':js}
return render(request,'html.html',context=js_)
--html.html--
....
<script>
{{js_script}}
</script>
But this does not properly work and a weird &quot is added in various places in the html source code everytime and the work is not accomplished. Please Help if you have a work around.

Just tried something and it worked.
source: django docs - safe templatetag
in context you are doing it right example:
context = {
'js_var': 'console.log("JavaScript which i want to add")',
}
in template add template tag "safe" it will remove the "&quot" 's:
<script>
console.log('sanity check');
{{js_var|safe}}
</script>
output:
sanity check
JavaScript which i want to add
Have a good day!
Tell me if this worked for you!

i think you want to load custom javascript code locally for particular page, to do that the proper way without mixing things, you need to define {% block %} in your base.html template and via DTL inheritance mechanism you can load you javascript the right way in right order without any conflict
in base.html define, let say {% block javascripts_local %}{% endblock %} like
{% load static %}
<!doctype html>
<html class="no-js" lang="{% block lang %}en{% endblock %}">
<head>
[..]
</head>
<body{% block body_attributes %}{% endblock %}>
[..]
{% block javascripts %}
<!-- i'm using HTML5 Boiler Plate template -->
<script src="{% static 'js/vendor/modernizr-3.7.1.min.js' %}"></script>
<script src="{% static 'js/plugins.js' %}"></script>
<script src="{% static 'js/main.js' %}"></script>
<!-- override this block in child template -->
{% block javascripts_local %}{% endblock %}
{% endblock %}
</body>
</html>
and then in your child template override the block
{% extends 'base.html' %}
{% load static %}
[..]
{% block javascripts_local %}
<script>
// Your javascript code goes here
</script>
{% endblock %}

Related

Separating JavaScripts file in symfony4 twig templates

I have a question about, how to separate a loading specify javascript file of specify template twig file.
I got for example admin.html.twig which extends base.html.twig, in base i got
{% block javascripts %}
<script src="/assets/js/core/jquery.min.js"></script>
<script src="/assets/js/core/popper.min.js"></script>
<script src="/assets/js/core/bootstrap-material-design.min.js"></script>
<script src="/assets/js/plugins/perfect-scrollbar.jquery.min.js"></script>
<script async defer src="https://buttons.github.io/buttons.j"></script>
<script src="/assets/js/plugins/chartist.min.js"></script>
<script src="/assets/js/plugins/bootstrap-notify.js"></script>
<script src="/assets/js/material-dashboard.min.js"></script>
<script src="/assets/demo/jquery.sharrre.js"></script>
<script src="/assets/js/sparkline.js"></script>
<script src="/assets/js/plugins/chartjs.min.js"></script>
{% endblock %}
and I got next file like dashboard.html.twig which extends a admin.html.twig file, and my question is that in dashboard.html.twig file i got at the a little writed-self small javascript code, and this javascript of course use a jquery library but this library i loaded in base.html.twig file a next of my selfwrited script which is in dashboard.html.twig.
My question is, how i can for example load my small code of javascript (of course i can save it in separated file like mycode.js) but how to load only when this route of dashboard.html.twig file i used and after jquery is loaded ? becouse in another routers i dont need this mycode.js so I dont wanna put it to base.html.twig file in javascript block, any idea ?
If dashboard directly extends admin then u can do the following to ensure to load all the admin scripts and to add the dashboard specific script:
{% extends "admin.html.twig" %}
{% block javascripts %}
{{ parent() }} {# execute the parent block, thus loading all scripts in admin #}
<script src="/assets/js/dashboard/mycode.js"></script>
{% endblock %}
You can dived
{% extends "admin.html.twig" %} {# use only in case your all templates are at the same places like app/Resources/views/admin.html.twig #}
{% block javascripts %}
{{ parent() }} {# loads the parent javascript block, from the template you are extending in first line. #}
<script src="/assets/js/dashboard/code.js"></script>
{% endblock %}
in case you are trying to extend a template from another bundle then you can use this
{% extends "YourBundleName:Default:admin.html.twig" %} {# YourControllerRelativeName just in case your view structure is like views/Default/admin.html.twig#}
{% block javascripts %}
{{ parent() }} {# loads the parent javascript block, from the template you are extending in first line. #}
<script src="/assets/js/dashboard/code.js"></script>
{% endblock %}
to the better understanding you should read a little here:
https://symfony.com/doc/2.8/templating.html
Note:- in the documents you should change version as per your current version.
I would suggest the following solution.
Declare the following block in base.html.twig after {% block javascripts %}{% endblock %}
{% block javascript_page %}{# specific code for current page #}{% endblock %}
Then in your page you can include page specific scripts
{% extends "admin.html.twig" %} or {% extends "base.html.twig" %}
{% block javascript_page %}
<script src="/assets/js/pages/my_page.js"></script>
{% endblock %}
Although answer by DarkBee is also correct but in this way you don't have to worry about calling {{ parent() }} in each page.

Django extended template is not loading base JS at time

I've in Django 1.11 a base.html which contains all the scripts references.
Then, I've another page.html that extendes base.html with {% extends base.html %} and {% block content %} / {% endblock content %} tags.
Well. In base.html I've a reference to Chartjs.js plugin. In page.html, if I try to call to Chart() function or just $ jquery, I get "function is not defined". If I open console debugger and try to call $ or just Chart(), it works. So I think that there's a problem with loading time. The page.html is rendered before the js are downloaded or requested!
How can I solve it? I've done it before, I don't know what could be the problem.
Thanks!
Without your code showing, hard to tell. Based on what you wrote, perhaps you forgot to put a block and block.super to get the parent (base.html's) Chartjs reference.
This should be in your page.html at the bottom after your {% endblock content %} tag. See example below (using DataTables as example since your code is not shown):
</div>
{% endblock content %}
{% block javascript %}
{{ block.super }}
<script type="application/javascript">
$(document).ready(function () {
$('#table').DataTable({
responsive: true,
});
});
</script>
{% endblock javascript %}
Base.html would have the js section enclosed in
{% block javascript %} …. {% endblock javascript %}

Django - passing variable to javascript file within same script tag

I am trying to pass my variable from Django's view to a javascript file. I read the stack question here (How can I pass my context variables to a javascript file in Django?) to get a few guidance but I am trying something a little bit different. I want to pass variable to the javascript file within that particular javascript reference script tag or changing the order of variable declaration. It is easier to show by example:
My somerandom.js:
console.log(variable);
What works:
{% extends base.html %}
{% load static %}
{% block body %}
<h1> Hello, World! </h1>
{% endblock body %}
{% block javascript %}
<script>
var variable = {{ my_var }};
</script>
<script src="{% static "app1/bootstrap/js/somerandom.js" %}"></script>
{% endblock javascript %}
What doesn't work:
Edit: It doesn't work because the in developer tool (press F12 in Chrome) I see this error: Uncaught ReferenceError: variable is not defined
1:
{% extends base.html %}
{% load static %}
{% block body %}
<h1> Hello, World! </h1>
{% endblock body %}
{% block javascript %}
<script src="{% static "app1/bootstrap/js/somerandom.js" %}"></script>
<script>
var variable = {{ my_var }};
</script>
{% endblock javascript %}
2:
{% extends base.html %}
{% load static %}
{% block body %}
<h1> Hello, World! </h1>
{% endblock body %}
{% block javascript %}
<script src="{% static "app1/bootstrap/js/somerandom.js" %}">
var variable = {{ my_var }};
</script>
{% endblock javascript %}
Reason I want those 2 to work is so I can organize and refer to my variables properly once my code gets longer. And in this link (http://www.mutaku.com/wp/index.php/2012/03/accessing-django-template-variables-in-javascript/), it shows that we can declare variable after referencing the javascript file.
When you use a <script> tag with a src= ... and a content in it the behavior is undefined, and is strongly related to the browser you're using: for instance with chrome the script is loaded from src=... and the content of the <script> is ignored
However the usage it's strongly discouraged
Enclosing the Django variable in double quotes worked for me. Then you invoke the .js file after the variable declaration.
<script>
var variable = "{{ my_var }}";
</script>
<script type="text/javascript" src="{% static ... %}"></script>
This is because console.log({{ my_var }}) does not print the variable to the console but console.log("{{ my_var }}") does print it.

JavaScript doesn't run in Django

I'm trying to find out how to run JavaScript in Django to create chained forms. But at the first I want to find out how to even run JavaScript. I've created a simple main.js file which is in static forder.
I've added a path to main.js into the head of html. And the script have to run when the page is loaded (just to be sure that I can step forward).
I've put alert on the beginning of the function so I can see whether the js has been run. But I can't see no alert nor js in chrome inspect.
Could you guys tell me where is the problem?
main.js
$(document).ready(function(){
alert("OK")
$.ajax({
url: "get-possible-levels/",
type: "POST",
data: {language: $('#id_language').val()},
})
})
template:
{% extends 'base.html' %}
{% load static %}
{% block head %}
<script src="{% static "js/main.js" %}"></script>
{% endblock %}
{% block content %}
{% if user.is_authenticated %}
<form action="" method="post" enctype="multipart/form-data">{% csrf_token %}
{{ language_form }}
<button value="Update" type="submit">Submit</button>
</form>
{% endif %}
{% endblock %}
View:
#login_required
def create_order(request):
language_form = LanguageLevelForm(request.POST or None)
return render(request,'auth/jobs/create-job-test.html',context={'language_form':language_form})
EDIT: The main.js seems to be executed but it does not alert anything. I've checked inspect (and I've tried to put semicolon after alert('ok')) :
Your {% load static %} should be {% load staticfiles %}. After that try refreshing the page the way I described in my comment. BTW Are you actually including JQuery? Your question is about JavaScript. You should try to use a vanilla JavaScript alert before adding JQuery code just to troubleshoot it. If you can get that working try adding this to your <head>
<script src="jquery-1.12.0.min.js"></script>
Check if you have the path to the js file wrong.if your project folder has 2 folders inside (one with html files and 1 with Js files) then on your path with the ../ you go up one level on your folder and then go inside your javascript folder to find the file. So instead of
<script src="{% static "js/main.js" %}"></script>
write
<script src="../js/main.js"></script>

how to organize JS files in Django?

I am currently working with a Django project, I include different libraries JS and I create JS files for manage the other libraries, but I don't know the correct organization of JS files for each html page, for example, I have a "Main.js" and "Milk.js" in base template but I don't want have both files in the same base template, I want separate files for each page..
I tried adding as a normal js file
<script src="{{ STATIC_URL }}js/milk.js"></script>
But it show me a error message asking me several dependencies when inherited from base.html
I hope your help
EDITED:
Cuando he añadido en mis archivos de plantillas, sin mostrarme error en la consola de cromo pero en la consola django mostrarme los archivos JS de carga con 304 error.
The libraries are in base.html
it's strange, I can load milk.js when I click from home.html but when I will click in other page for example "cow.html" from "Milk.html" no load js file even when I did the same as "milk.html".
Django template engine has already provided a tag for inherit your HTML structure called 'extend'.
Tag "extends" is a using for extends a parent template.
{% extends "base.html" %} uses the literal value "base.html" as the name of the parent template to extend.
base.html is the parent template that can extendable.
{% load staticfiles %}
<html lang="en">
<head><title>Hello World</title></head>
<body>
<div id="content">
{% block content %}{% endblock %}
</div>
{% block scripts %}
<script src="{% static 'js/main.js' %}"></script>
{% endblock %}
</body>
</html>
and you have another HTML called milk.html that you need everything same as the base.html but include milk.js you just do something like this.
{% load staticfiles %}
{% extends "base.html" %}
{% block scripts %}
<!-- block.super will get the content of the block from the parent template -->
{{ block.super }}
<script src="{% static 'js/milk.js' %}"></script>
{% endblock %}
Read more about docs[1]: [1]: https://docs.djangoproject.com/en/dev/ref/templates/builtins/#std:templatetag-extends
In your base.html file, add a block inside the head tag like this:
{% block scripts %}
<!-- some default content here -->
{% endblock %}
Now in your different templates files:
{% block scripts %}
<!-- insert per template scripts here -->
{% endblock %}
So in the templates with Milk, it would be like:
{% block scripts %}
<script src="{{ STATIC_URL }}js/milk.js"></script>
{% endblock %}
Being lazy, and extending the admin templates with {% extends admin/base.html %} I found that using {% block scripts %} did not work. The JavaScript was not sent to the browser. However base.html has a built-in block {% block extrahead %} which is empty and just the ticket for inserting additional content like scripts into the header.
{% block extrahead %}
<script src="{{ STATIC_URL }}js/milk.js"></script>
{% endblock %}

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