make django model field read only or disable in admin while saving the object first time

Question

I want to disable the few fields from model in django admin while saving initially.

"<input type="text" id="disabledTextInput" class="form-control" placeholder="Disabled input">"

like this.

My model is:

class Blogmodel(models.Model):
    tag = models.ForeignKey(Tag)
    headline = models.CharField(max_length=255)
    image=models.ImageField(upload_to=get_photo_storage_path, null=True, blank=False)
    body_text = models.TextField()
    pub_date = models.DateField()
    authors = models.ForeignKey(Author)
    n_comments = models.IntegerField()

i want to disable the "headline" and "n_comments". i tried it in admin.py file, but its not disabling the fields on initial saving. But for editing the fields its working, it making the fields read only.

in admin.py

class ItemAdmin(admin.ModelAdmin):
    exclude=("headline ",)
    def get_readonly_fields(self, request, obj=None):
        if obj:
            return ['headline']
        else:
            return []

Headling getting disabled but for edit only. i want to disable it at the time of object creation. i.e. first save. can anyone guide me for this?

Susurrate

Why are you not using readonly_fields property instead? – Rosenfeld

it will work for editing the objects not for creating the object first time. – Susurrate

It will work for both if you are not overwriting get_readonly_fields. – Rosenfeld

Answer 1

If you want to make the field read-only during creation you should do it the other way round:

def get_readonly_fields(self, request, obj=None):
    if obj is None:
        return ['headline']
    return []

Strongwilled

it worked thanks a lot. But its not showing the input box disabled. – Susurrate

hay its not working for edit!!. While editing its not disabled. – Susurrate

Sorry I misunderstood the question, thought you only want to disable it for creating... otherwise just always return ['headline']... No need for the If-clause... – Strongwilled

Answer 2

There is no need to override get_readonly_fields. Simplest solution would be:

class ItemAdmin(admin.ModelAdmin):
    exclude=("headline ",)
    readonly_fields=('headline', )

When using readonly_fields you can't override get_readonly_fields, because default implementation reads readonly_fields variable. So overriding it only if you have to have some logic on deciding which field should be read-only at time.

Rosenfeld

I have no idea why people are not using your simple suggestion here – Anent

This is the way to go! – Eldoraeldorado

great solution! – Kolnick

Answer 3

Just do editable=False, while adding the field in the model

headline = models.CharField(max_length=255,editable=False)

It wont be editable and you cannot see the field from admin panel, but you can add values to them from a method within the model

Hinduism

Answer 4

Other way is:

    def get_form(self, request, obj=None, **kwargs):
        form = super().get_form(request, obj=None, **kwargs)

        if obj is None:

            form.base_fields["my_field"].disabled = True

        return form

Colossae