form_add with pre-filled fields

[Jérôme Le Carrou]

Hi,

I have a models with 3 classes: Visite, Inclusion, BilanBiologique and ExamenBiologique

- Inclusion is linked to Visite (OneToOne)
- BilanBiologique is linked to Visite (ForeignKey)
- ExamenBiologique is linked to BilanBiologique (ForeignKey)
- ExamenBiologique is a subform of BilanBiologique

I use Django admin form
I try to customize my Inclusion admin form to

- have a link that redirect user to BilanBiologique
AND
- I would like the "vis" field (which is the ForeignKey) to be pre-filled with the corresponding value (I can retrieve this value from Inclusion)

I manage to display a link from Inclusion to BilanBiologique using a method "examen" in Inclusion class
I have think about using GET method but to be honest I am lost... I have no idea how to proceed...

models.py

    class Visite(models.Model):
        vis_ide = models.AutoField(primary_key=True)
        pat = models.ForeignKey(Participante, verbose_name='Participante', related_name='visites', on_delete=models.CASCADE)
        vis_dat = models.DateField("Date de consultation")
   
        def __str__(self):
            return f"{self.pat.pat_ide_prn_cse} / {self.vis_dat}"
   
    class BilanBiologique(models.Model):
        bio_ide = models.AutoField(primary_key=True)
        vis = models.ForeignKey(Visite, verbose_name='Visite', on_delete=models.CASCADE)
        bio_dat = models.DateField("Date de prélèvement")
   
        def __str__(self):
            return f"{self.bio_ide}"
   
        @property
        def date_visite(self):
            return self.vis.vis_dat
   
        date_visite.fget.short_description = 'Date de la visite'
   
        @property
        def participante(self):
            return self.vis.pat.pat_ide_prn_cse
   
        participante.fget.short_description = 'Participante'
   
    class ExamenBiologique(models.Model):
        bio_exa_ide = models.AutoField(primary_key=True)
        bio = models.ForeignKey(BilanBiologique, verbose_name='Bilans', related_name='examens',on_delete=models.CASCADE)
        bio_exa_cod = models.IntegerField("Type d'examen")
        bio_exa_res_num = models.FloatField("Résultat numérique", null=True, blank=True)
        bio_exa_res_mod = models.IntegerField("Résultat modalité", null=True, blank=True)
        bio_exa_uni = models.IntegerField("Unité", null=True, blank=True)
        bio_exa_val_inf = models.FloatField("Limite inférieure", null=True, blank=True)
        bio_exa_val_sup = models.FloatField("Limite supérieure", null=True, blank=True)
   
        def __str__(self):
            return f"{self.bio_exa_ide}"
   
    class Inclusion(models.Model):
        readonly_fields = ('examen',)
   
        inc_ide = models.AutoField(primary_key=True)
        vis = models.ForeignKey(Visite, verbose_name='Visite', related_name='inclusions', on_delete=models.CASCADE)
        inc_tdr = models.IntegerField("Test rapide Determine® VHB (AgHBs)")
   
        def examen(self):
            changeform_url = reverse('admin:ecrf_bilanbiologique_add')
            return mark_safe('<a href="{u}" target="_blank">Ajouter un bilan</a>'.format(u=changeform_url))
        examen.short_description =''
        examen.allow_tags = True
   
        def __str__(self):
   
            return f"{self.vis} / {self.inc_ide}"

admin.py

    from django.contrib import admin
    from .models import Participante, Visite, Inclusion, BilanBiologique, ExamenBiologique
    from .forms import InclusionFormAdmin, BilanBiologiqueFormAdmin
   
    class ExamenBiologiqueInline(admin.TabularInline):
        model = ExamenBiologique
        extra = 0
   
    class BilanBiologiqueAdmin(admin.ModelAdmin):
        inlines = [ExamenBiologiqueInline,]
   
    class BilanBiologiqueLinkInline(admin.TabularInline):
        readonly_fields = ('examen', )
        model = BilanBiologique
        extra = 0
        fields = ('bio_ide', 'vis', 'bio_dat','examen')
        form = BilanBiologiqueFormAdmin
   
    class VisiteAdmin(admin.ModelAdmin):
        inlines = [BilanBiologiqueLinkInline,]
   
    class InclusionAdmin(admin.ModelAdmin):
        readonly_fields = ('examen',)
        model = Inclusion
        fields = ('vis',('inc_tdr','examen'),)
        form = InclusionFormAdmin
   
   
    admin.site.register(Participante)
    admin.site.register(Visite, VisiteAdmin)
    admin.site.register(BilanBiologique, BilanBiologiqueAdmin)
    admin.site.register(Inclusion, InclusionAdmin)