Accessing a python function from a blog post stored in the db?

[Dennis Marwood]

Hi. I am looking for some advice on the best way to approach the following:

I am pulling my blog posts out of my db. Inside of the posts I want to use an image scroller ( http://cssdeck.com/labs/css3-image-slider ), but I don't want to write all of the boilerplate surrounding each image every time.

The idea I have is a template filter.... but that just seems wrong. What's the proper way to handle this?

Ideally, I would just add some bit in my post like css_slider({loc: loc_pic_1, desc: "blah blah"}, {loc: loc_pic_1, desc: "blah"}...)

[Jonathan Baker]

This sounds like a good fit for an inclusion tag. Since you need a bit of markup around the images for the slider functionality, it'd be nice to keep that markup in a separate template so you could use the image slider in multiple places like, say, a post detail page as well as a dashboard. Then, anytime you wanted to create image slider, in your template you could simply do something like:

{% load image_extras %}

...

{% image_slider post.image_set %}

...

Docs: https://docs.djangoproject.com/en/dev/howto/custom-template-tags/#inclusion-tags

JDB

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[Dennis Marwood]

Thanks. I believe this is what I am looking for. However I am still running into an issue w/ the fact that I am pulling my blog entries from the db. This is causing the template to interpret the {% image_slider %} as a string.

From view.py:
def blog(request):
    entries = Project.objects.filter(destination="blog").order_by('-creation_date')
    return render(request, 'content.html', {"entries": entries,
                                               "page_title": "Blog",
                                               "description": "Blog"})

And in content.html:
{% for each in entries %}
<p>{{ each.entry }}</p>
{% endfor %}

And a blog entry:
Hello! Check out this collection of images. {% image_slider %} And this collection! {% image_slider %}


I don't want to hard code the inclusion tag in the content.html. Instead I want to call it from the blog post. Is this possible?

[Tom Evans]

On Wed, Feb 26, 2014 at 5:29 AM, Dennis Marwood <dennis...@gmail.com> wrote:
> Thanks. I believe this is what I am looking for. However I am still running
> into an issue w/ the fact that I am pulling my blog entries from the db.
> This is causing the template to interpret the {% image_slider %} as a
> string.
>
> From view.py:
> def blog(request):
> entries =
> Project.objects.filter(destination="blog").order_by('-creation_date')
> return render(request, 'content.html', {"entries": entries,
> "page_title": "Blog",
> "description": "Blog"})
>
> And in content.html:
> {% for each in entries %}
> <p>{{ each.entry }}</p>
> {% endfor %}
>
> And a blog entry:
> Hello! Check out this collection of images. {% image_slider %} And this
> collection! {% image_slider %}
>
>
> I don't want to hard code the inclusion tag in the content.html. Instead I
> want to call it from the blog post. Is this possible?

Yes. You will need to write a custom template tag to parse the
contents of the object as a template, render it within the current
context and return the generated data.

Writing a custom template tag:

https://docs.djangoproject.com/en/1.6/howto/custom-template-tags/#writing-custom-template-tags

Rendering templates to string:

https://docs.djangoproject.com/en/1.6/ref/templates/api/#rendering-a-context

Your content.html would then look something like this, assuming you
called the custom tag 'render':

{% for each in entries %}

<p>{% render each.entry %}</p>
{% endfor %}

Beware the massive security holes if you allow users to generate
content that your site then renders as a template.

Cheers

Tom

[Dennis Marwood]

Thanks. I look forward to trying this soon.

I feel like I may be trying to swim against the current with this. Is this a problem with the way that I have decided to implement my blog or are these workarounds typical for django applications?

[C. Kirby]

It sounds like your implementation is a little skewed.
If a blog post is made of multiple resources (summary, body, multiple image collections, etc.) You should probably have a model or models with the appropriate fields/relationships.  That way your template can house all of the template language, and you build a single, user facing blog post from the elements in the blog post model(s).
This also gives you the benefit of making the various resources available in other ways (eg. Show all my image collections, share collections, etc) as well as change your layout in the future without having hard-coded template calls in your content.

Regards
~CK

[Dennis Marwood]

Won't this force my blog posts to all be the same. i.e. Text then a image scroller?
How would I handle the case where a blog post was Text, image scroller, text, image scroller?

[C. Kirby]

It doesn't have to, I guess it depends on how involved the creation tools are that you create. Quick and dirty idea off the top of my head:
If the authoring tools define post widgets (body, text, scroller, video, etc) you could let authors drag and drop the elements as they wish. On the model side, make all resources extend a base class of BlogResource type, then for each blog post have a many to many through table that stores ordering:
PostID(foriegn=blog)
ResourceID(genericforeignkey to blog resource)
OrderID(int)

or somthing like that.

Regards,
~CK

[Dennis Marwood]

OK I think you are talking about something like https://docs.djangoproject.com/en/dev/intro/tutorial02/#adding-related-objects where I could just insert a slider type of entry and then a text entry and so on. Is that it?

[C. Kirby]

Broadly speaking, yes. The details may get hairy, but those are probably better dealt with in issue specific threads.

Good luck, and don't hesitate to bring up any other questions.

~CK