In Django how to retrieve substring till ocurrence of a dot, from a model, to show in a template-CodePudding

I have the following model:

class News(models.Model):
    news_text = models.TextField(null=True)
    ... # other fields

with the following view:

def news(r):
    news= News.objects
    values = {'news':news}
    return render(r,'webapp1/news.html',values)

I want to show in the template a substring for the column news_text, till the first 'dot' occurrence, like:

{{news.news_text| split('.')[0] }}

Tried this in template but got: "invalid filter: 'split'".

First post on stackoverflow ;)

CodePudding user response：

Django has a limited set of builtin template filters and there is no split filter.

Also in Django templates you can access object's attributes or methods like {{my_dict.keys}}, but you can't pass any arguments. So you can't do things like {{news.news_text.split('.')}} as well.

All of this is done with intention to force you to separate logic from templates. So for your example probably will be better to define a special context variable and pass it into template's rendering context, like:

def news(r):
    news = News.objects.all().get()  # don't forget to call some filters on object manager
    context = {
        'news': news,
        'headlines': news.news_text.split('.')[0],
    }
    return render(r, 'webapp1/news.html', context)

Also note that plural model names may be confusing: is it an array of news in each entry, or not?

Nevertheless you can create custom template tags and filters (and in many cases you should) to solve your problem.