Published by Alfred
Filled under: Data Storage, Django, MongoDB, Python
8 Comments

MongoDB ID’s and Django templates

So. Ran into a little frustration using MongoDB with Django; if you try to represent the _id field of a mongo object using something like {{ mongo_object._id }} or {{ mongo_object.id }}, you will get nothing but django barf. To circumvent this you can simply create a template filter. Don’t be scared . . . it’s actually pretty simple. Let get to it:

  1. first off create the following folder and files:
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    mkdir -p /path/to/project/appName/templatetags
touch /path/to/project/an_app/templatetags/__init__.py
touch /path/to/project/an_app/templatetags/appName_tags.py
  2. It is important that you make the directory/files inside of an app folder and name it exactly templatetags. the file appName_tags.py can be named anything as long as it has a .py extension.
  3. now paste the following code inside of appName_tags.py:
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    from django import template
register = template.Library()
 
@register.filter("mongo_id")
def mongo_id(value):
    return str(value._id)
  4. all that is left is to utilize this filter. to do this, we simply load it inside of the corresponding template and viola: 
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    <html>
 <body>
  {% load appName_tags %}
  <p>here is your mongodb record id: {{ object|mongo_id }}</>
 </body>
</html>

tip: custom filters can also take two arguments instead of the one shown above. check out this example below (referenced from here):

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8 Comments

  1. Jeff Terry wrote:
    March 6, 2010 at 5:11 pm

    Thanks for your post. I am new at programming and this is a big help.

    Reply
  2. Raelene Thomas wrote:
    March 6, 2010 at 7:37 pm

    Thanks for your post. I am new at django and this got me straight.

    Reply
  3. Alfred wrote:
    April 1, 2010 at 11:30 pm

    np. let me know if you guy’s find it useful.

    Reply
  4. Drug Identification wrote:
    May 19, 2010 at 11:02 am

    I saw this really great post today!

    Reply
  5. ehcache.net wrote:
    March 18, 2011 at 3:16 pm

    MongoDB ID’s and Django templates…

    So. Ran into a little frustration using MongoDB with Django; if you try to represent the _id field of a mongo object using something like {{ mongo_object._id }} or {{ mongo_object.id }}, you will get nothing but django barf. To circumvent this you can …

    Reply
  6. Claudiu wrote:
    September 1, 2011 at 3:24 pm

    thanks for this tutorial!
    I wanted to say that for me it did not work with “return str(value._id)” I had to write “return str(value.['_id'])”

    Reply
  7. Jakob wrote:
    February 3, 2012 at 9:30 am

    This “filter” works better: http://d-w.me/blog/2010/1/15/8/

    Got an error using your code:

    def mongo_id(value):
    return str(value._id)

    Reply