Django call model functions from template

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Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. Podcast Making Agile work for data science. Stack Gives Back Featured on Meta. New post summary designs on greatest hits now, everywhere else eventually. Linked Django actually prevents this by design. The idea is to keep most of the logic in views and keep the template language as simple as possible so that it can easily be used by non tech-savvy designers, for example.

Quoting from the doc:. Data should be calculated in views, then passed to templates for display. So you'll have to do that in the view. Writing a custom template tag or filter might also be of good help.

This is a common problem, so don't hesitate to ask on the django-users mailing list for more advice. Thanks for the update. Is the goal to provide an additional layer of security against people who only have access to the templates? I agree that this is a fine goal, but I think that the alternatives either pre-packing information you know you're going to want or being forced to write a custom template tag for each additional method you want to use are un-pythonic and un-djangonic enough to warrant some kind of change.

Perhaps just try to include the request as an argument to the function call, and don't if there's a TypeError for a mismatched number of arguments? It defaults to 'utf-8'. This can be used to add new libraries or provide alternate labels for existing ones. For example:. Requires Jinja2 to be installed:. Jinja2' to configure a Jinja2 engine. It defaults to 'jinja2.

Django invokes that callable and passes other options as keyword arguments. Environment as described below. You can then call that function in the template:. Some Django templates context processors return a fixed value. Unless all of these conditions are met, passing a function to the template is more in line with the design of Jinja2.

The default configuration is purposefully kept to a minimum. If a template is rendered with a request e. In order to use Django-specific APIs, you must configure them into the environment. Since Jinja2 supports passing arguments to callables in templates, many features that require a template tag or filter in Django templates can be achieved by calling a function in Jinja2 templates, as shown in the example above.

Offline Django 4. Django is a registered trademark of the Django Software Foundation. Django The web framework for perfectionists with deadlines. Documentation Search: Search. Getting Help el es fr id it ja ko pl pt-br zh-hans Language: en 1.

You can also write your own custom backend, see Custom template backend Django defines a standard API for loading and rendering templates regardless of the backend. My first name is John. My last name is Doe.

It accepts the following optional arguments for populating the template postmortem on the debug page: backend The template backend instance from which the exception originated. It defaults to True. Using context processors with Jinja2 templates is discouraged. I have a model called "History" and inside this model I've a specialized function that will handle the inserts to this model. I've another alternative that I've tested and it works, but does not feel the right way.

The code looks like this:. BTW, the conventional name for a method creating new objects is create. The easiest way is to override the save method :. Now, whenever you save your method - field3 's value will be whatever is the result of the calculation in your custom save method.

You don't need to modify anything in your views for this to work. Just to extend on answer by burhankhalid, as I were unable to comment due to rather high-ish rep requirement, I had a similar need to alter another model while saving mine, but solution proposed by Burhan Khalid helped me to start. My proposal assumes that Request would have a 'attrib1', and to that it tries to save the value from History. So the whole concept of rewriting the save method and modifying and saving other objects as well made the difference.

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