How to show different inlines depending of current object field value

@Yuji 'Tomita' Tomitayou the idea was good, i had the same but once trying, i realized you must also remove specific key from self.inlines because in change_view and add_view method self.get_inline_instances(request) is called before get_formsets(). Therefore i moved inlines handling to get_form() method.

Here is how i sucessfully did it:

class SampleAdmin(ModelAdmin):    inlines = []    def get_inlines(self):        return [SampleInline, SampleInline2]    def get_form(self, request, obj=None, **kwargs):        # due to django admin form fields caching you must         # redefine inlines on every `get_form()` call        if (obj): self.inlines = self.get_inlines()        for inline in self.inlines:            # Here change condition based on your needs and manipulate            # self.inlines as you like (remove, change, etc).             # I used inline.__name__ to detect if this is correct inline             # for my obj            if obj.CONDITION:                self.inlines.remove(inline)        return super(SampleAdmin, self).get_form(request, obj, **kwargs)

I realize this question's a bit old and the codebase has changed a bit; there's a cleanish point to override things at now: get_inline_instances. You can do this:

class MainModelAdmin(models.ModelAdmin):    inlines = [RelatedModel1InlineAdmin,RelatedModel2InlineAdmin]    def get_inline_instances(self, request, obj=None):        #Return no inlines when obj is being created        if not obj:            return []        unfiltered = super(MainModelAdmin, self).get_inline_instances(request, obj)        #filter out the Inlines you don't want        if obj.type:            return [x for x in unfiltered if isinstance(x,RelatedModel1InlineAdmin)]        else:            return [x for x in unfiltered if isinstance(x,RelatedModel2InlineAdmin)]

This worked for me while searching for an answer to the same problem in this old post.Expanding upon darklow's answer , I think you can simply override get_inline_instances completely and add an extra check based on your type.

1. Add a boolean type check method in your model

   class MainModel(models.Model):    name = models.CharField(max_length=50)    type = models.BooleanField()    def is_type1(self):       return type=="some value"    def is_type2(self):        return type=="some value"

2. Add inline instance base on type check - Simply copy and paste the get_inline_insances method from the parent class into your admin.ModelAdmin class and add the if block to check the model type as shown below

   class MyModelAdmin(admin.ModelAdmin):    inlines = [RelatedModel1, RelatedModel2]    def get_inline_instances(self, request, obj=None):        inline_instances = []        if not obj:            return []        for inline_class in self.inlines:            inline = inline_class(self.model, self.admin_site)            if request:                if not (inline.has_add_permission(request) or                            inline.has_change_permission(request, obj) or                            inline.has_delete_permission(request, obj)):                    continue                if not inline.has_add_permission(request):                    inline.max_num = 0            if obj.is_type1() and isinstance(inline,RelatedModel1InlineAdmin):                inline_instances.append(inline)            if obj.is_type2() and isinstance(inline,RelatedModel2InlineAdmin):                inline_instances.append(inline)        return inline_instances