How to add a record field to a form#

This guide adds a searchable field that chooses a dataset to a form of your own. The person typing sees the datasets they may reach, and the form refuses any other. You would do this on a form that puts something inside a dataset, or links to one.

Before you start#

The form is built in a request, in a view, or you pass the request to it yourself.
For every argument of the field, see Record fields.

Steps#

Import the field for the kind of record you want to choose. FairDM has one for projects, datasets, samples, measurements, people and organizations.
```
from fairdm.contrib.autocomplete.fields import DatasetChoiceField
```

Declare it on the form and say what the person needs to be able to do with the record. A record that your form places something inside needs scope="edit". A record the form only links to needs the default, "view".

from django import forms

from fairdm.contrib.autocomplete.fields import DatasetChoiceField


class AddToDatasetForm(forms.Form):
    name = forms.CharField()
    dataset = DatasetChoiceField(scope="edit")

Build the form inside a request.
```
form = AddToDatasetForm(request.POST or None)
```
The field finds the person through the request the form is built in. A form that has a request attribute, as FairDM’s own record forms do, uses that request instead.

Use the cleaned value. It is a Dataset.

if form.is_valid():
    dataset = form.cleaned_data["dataset"]

The result#

On the page, the person types part of the dataset’s name and is offered the datasets they may edit, with each dataset’s project beneath its name. A dataset they may not edit is refused with the field’s invalid_choice error, whatever the browser sent.

Choose several records#

Use the multiple field. It takes the same arguments and offers the same records as the single field.

from django import forms

from fairdm.contrib.autocomplete.fields import ProjectMultipleChoiceField

class ProjectPickerForm(forms.Form):
    projects = ProjectMultipleChoiceField()

Offer one person’s records#

On a page that lists one person’s records, give the field that person as owner. It offers their private records to them and public records to everyone else. owner cannot be given with scope. It is a value of the page being shown, so create the field when the page is built, in the form’s __init__ or in the filter set’s.

from fairdm.contrib.autocomplete.fields import ProjectMultipleChoiceField

projects = ProjectMultipleChoiceField(owner=person)