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PODjango: Traversing multiple successive ManyToMany relationships in templates in one loop
 

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    <p>I have a situation like this: there are three Django models, let's call them article, section and tag, and one through-model.</p> <pre><code>class Tag(models.Model): name = models.CharField(max_length=100, primary_key=True) class Section(models.Model): # all sorts of fields here class Article(models.Model): tags = models.ManyToManyField(Tag, null=True, blank=True) sections = models.ManyToManyField(Section, null=True, blank=True, through='SectionInArticle', related_name='articles') class SectionInArticle(models.Model): article = models.ForeignKey(Article) section = models.ForeignKey(Section) order = models.IntegerField() </code></pre> <p>Then, in the section's detail template, I want to list all the tags from the related articles. To do that, I first have to traverse the Section-Article ManyToMany relationship in reverse (using the related_name), and then traverse the Article-Tag ManyToMany relationship. I tried this:</p> <pre><code>{# doesn't print anything: #} {% for tag in object.articles.tags.all %} {{ tag.name }} {% endfor %} </code></pre> <p>but for some reason, that didn't work. {% for tag in object.articles.all.tags.all %} didn't work either. I can print all the tags using nested loops, but that means duplicates become a problem.</p> <pre><code>{# duplicates are an issue here: #} {% for article in object.articles.all %} {% for tag in article.tags.all %} {{ tag.name }} {% endfor %} {% endfor %} </code></pre> <p>Is there a neat way to do this in Django templates, or do I have to put it in the view code? If so, what would be the be the cleanest way to do it there so I can avoid duplicate tags in the list?</p>
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A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

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