Add a placeholder to a form based on a model charfield

Using Django Templates & Frontend
1

I have a form:

class SideEffectForm(ModelForm):

    class Meta:
        model = SideEffect
        fields = ['se_name']

    def __init__(self, *args, p, **kwargs):
        super().__init__(*args, **kwargs)

        if p == 'antipsychotic':

            self.fields['se_name'].choices = [
                ("insomnia_and_agitation", "Insomnida and Agitation"),
                ("akathisia", "Akathisia"),
                ("dystonia", "Dystonia"),
            ]

That is based on this model:

class SideEffect(TimeStampedModel):

    SE_CHOICES = [
        ("insomnia_and_agitation", "Insomnida and Agitation"),
        ("akathisia", "Akathisia"),
        ("anticholinergic_effects", "Anticholinergic Side Effects")
    ]

    se_name = models.CharField("",max_length=200, choices=SE_CHOICES, blank=False)

    concern = models.IntegerField("",default=50)

    case = models.ForeignKey(Case, on_delete=models.CASCADE)

I have a form:

class SideEffectForm(ModelForm):

    class Meta:
        model = SideEffect
        fields = ['se_name']

    def __init__(self, *args, p, **kwargs):
        super().__init__(*args, **kwargs)

        if p == 'antipsychotic':

            self.fields['se_name'].choices = [
                ("insomnia_and_agitation", "Insomnida and Agitation"),
                ("akathisia", "Akathisia"),
                ("dystonia", "Dystonia"),
            ]

That is based on this model:

class SideEffect(TimeStampedModel):

    SE_CHOICES = [
        ("insomnia_and_agitation", "Insomnida and Agitation"),
        ("akathisia", "Akathisia"),
        ("anticholinergic_effects", "Anticholinergic Side Effects")
    ]

    se_name = models.CharField("",max_length=200, choices=SE_CHOICES, blank=False)

    concern = models.IntegerField("",default=50)

    case = models.ForeignKey(Case, on_delete=models.CASCADE)

As it stands the form displays the first option. I would however like to have a place holder e.g. ‘Please select a side effect’. I could do this by having it as one of the options but would prefer not to as then would need to implement measures to stop the placeholder being saved as a valid user entry. Is there a way to specify a placeholder?

2

The HTML select element does not provide for such a feature.

You do have at least two options:

  • See the last paragraph in the section for Field choices

  • Find a usable JavaScript-based select widget that provides that functionality.

1 Like
3

That’s totally possible.

Check out the docs at Model field reference | Django documentation | Django

Unless blank=False is set on the field along with a default then a label containing "---------" will be rendered with the select box. To override this behavior, add a tuple to choices containing None ; e.g. (None, 'Your String For Display') . Alternatively, you can use an empty string instead of None where this makes sense - such as on a CharField.

And you already set the se_name field as blank=False. So you need to add a (None, "Display Value") to your SE_CHOICES

4

Thanks @leandrodesouzadev might you then also be able to advise how i ensure the user cannot submit the form while the (None, 'Your String For Display') option is selected (i.e. force them to make a choice before submitting the form)

Thanks!

5

Since you want that to happen in the browser, you would need to write some JavaScript that handled the submit button to validate that field before processing the submit.

1 Like