I want to write a template that renders something only one time.
My idea is to create a flag variable to check it is the first time.
My code
{% with "true" as data %}
{% if data == "true" %}
//do something
** set data to "false" **
{% else %}
//do something
{% endif %}
{% endwith %}
I don't know How to change a variable in django template. Is it possible? Or is there a better way to do this?
This can be done with a Django custom filter
django custom filter
def update_variable(value):
data = value
return data
register.filter('update_variable', update_variable)
{% with "true" as data %}
{% if data == "true" %}
//do somethings
{{update_variable|value_that_you_want}}
{% else %}
//do somethings
{% endif %}
{% endwith %}
NIKHIL RANE's answer doesn't work for me. Custom simple_tag() can be used to do the job:
#register.simple_tag
def update_variable(value):
"""Allows to update existing variable in template"""
return value
and then use it like this:
{% with True as flag %}
{% if flag %}
//do somethings
{% update_variable False as flag %}
{% else %}
//do somethings
{% endif %}
{% endwith %}
Related
Is something like this possible in a template?
{% if request.path == url 'posts:post_detail' pk=instance.id %}
If not, how can I achieve this result being True? I want to this to be true when user is looking at a specific post such as post/1.
Yes, you can using the as var syntax:
{% url 'posts:post_detail' pk=instance.id as the_url %}
...
{% if request.path == the_url %}
...do something
{% endif %}
I need to have a nested loop in my Django template, where the outer loop goes through a list of objects, and the inner loop goes through a list of those object id's, and I want to only do something for the id's on the inner list, it never executes however. I think it has something to do with the condition for the if statement, because if I replace it with a true statement it works but it doesn't work as it is now
(I have checked to see that the id's overlap)
{% for outer in outer_obj_list %}
{% for inner_id in inner_id_list %}
{% if outer.id == inner_id %}
// do something
console.log({{inner_id}});
console.log({{outer.id}});
{% endif %}
{% endfor %}
{% endfor %}
Syntax seems correct. I would just verbosely output everything.
Perhaps it should be something like this:
{% for main_obj in main_obj_list %}
main_obj: {{ main_obj }}
{% for obj_id in obj_id_list %}
obj_id: {{ obj_id}}
main_obj: {{ main_obj.id}}
{% if main_obj.id == obj_id %}
// do something
match: {{main_obj.id}} == {{obj_id}} ;
{% endif %}
{% endfor %}
{% endfor %}
Brother I am also face this problem so my clever mind get some clever solution about this problem we can do that with JavaScript easily so we need to run it in JavaScript and then.
{% for outer in outer_obj_list %}
{% for inner_id in inner_id_list %}
if(outer.id == inner_id.id ){
console.log({{inner_id.id}});
console.log({{outer.id}});
//And also if we reserve place in DOM then we can
//change the inner Html of them easily like.
//demo = document.getElementById("demo");
//demo.innerHTML = inner_Id.id or outer.id
}
{% endfor %}
{% endfor %}
I have something like the following:
{% for i in "xxxxxxxxx" %}
...
{% if passedInList.*forloop.counter0|add:"1"* %} Do Something {% endif %}
...
{% endfor %}
Obviously the if statement is incorrect. I have been using this method to create index names in forms for quite some time, but have never had to use the for loop counter index in an if statement.
Is this possible? If so, how would I go about doing so?
Thanks!
Try to use a with statement to save the forloop counter in a context variable, like so:
{% with index=forloop.counter %}
{% if passedInList.index %} do something {% endif %}
{% endwith %}
(Also, seems like you can use forloop.counter instead of forloop.counter0|add:"1")
So I have this in a Django template.
{% if request.get_full_path = "/blog/" %}
do something
{% endif %}
Which does exactly what I want when I go to http://somesite.com/blog/
What I want to do is also include all subdirectories.
So something like
{% if request.get_full_path = "/blog/*" %}
do something
{% endif %}
Unfortunately as far as I can tell Django doesn't do wildcards in templates. So how do I do this?
Try with this:
{% if request.get_full_path|slice:'0:6' == '/blog/' %}
My coding is:
views
def showThread(request, thread_id)
post_list = Post.objects.filter(id = thread_id)
post_likes = PostLikes.objects.all()
return render_to_response('show.html',locals(),context_instance=RequestContext(request))
models:
class Post(models.Model):
subject = models.CharField(max_length = 250)
body = models.TextField()
thread = models.ForeignKey('self', null = True, editable = False )
Show.html:
{% for post in post_list %}
{{post.id}}{{post.subject}}
{% endfor %}
{% for post_like in post_likes %}
{% if post_like.post_id == post.id and post_like.user_id == user.id %}
U like this post{{post}}
{% else %}
{{post}}
{% endif %}
{% endfor %}
In the show.html, else part, it displays the values again and again. But i need only one time.How can i break the for loop when i enter into else condition.Please help me..
Django's for tag doesn't provide you with any means to break out of the loop. You'll simply have to filter the collection in your own view and slice it after the point your condition fails and supply that to your template.
You can use the django custom template tag found in this django snippets page. If you have doubts on using it, go to this page to learn about custom template tags.
Then load the template tag in your template using {% load loop_break %}. Then you can break the for loop as given below:
{% for post_like in post_likes %}
{% if post_like.post_id == post.id and post_like.user_id == user.id %}
U like this post{{post}}
{% else %}
{{post}}
{{ forloop|break }}
{% endif %}
{% endfor %}
Here the for loop will break when it enters the else part.
you could probably use ifchanged tag:
https://docs.djangoproject.com/en/dev/ref/templates/builtins/?from=olddocs#ifchanged
However, you probably should consider moving this logic to view.
If you can structure your if statement to detect when you want to output nothing, you can simply put nothing inside your else clause:
{% for post_like in post_likes %}
{% if post_like.post_id == post.id and post_like.user_id == user.id %}
U like this post{{post}}
{% else %}
{% if forloop.first %}
{{post}}
{%else%}{%endif%}
{% endif %}
{% endfor %}
The above might not do quite what you want - you will have to tweak it yourself. The only thing you can't do is set a flag that this is the first entry into the else clause.