# Read imageField attribute before send it

**URL:** <https://forum.djangoproject.com/t/read-imagefield-attribute-before-send-it/7469>\
**Category:** Using Django\
**Created:** [April 10, 2021, 5:27pm UTC](https://forum.djangoproject.com/t/read-imagefield-attribute-before-send-it/7469 "2021-04-10T17:27:06Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![julianov](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.djangoproject.com/julianov/32/3502_2.png) [@julianov](https://forum.djangoproject.com/u/julianov)\
**Post date:** [April 10, 2021, 5:27pm UTC](https://forum.djangoproject.com/t/read-imagefield-attribute-before-send-it/7469/1 "2021-04-10T17:27:06Z")

</div>

I have a model, which has 3 ImageField. When loading a new entry into the database, it may have some blank images, so the value is None. When the client request the model data entry, I get in the server side:

> ValueError: The ‘picture2’ attribute has no file associated with it.

The problem is in the imageField.read() when there is not a file to read. How can I solve it without check with if statment if there is or not a file?

```auto
class item (models.Model):

    certificate=models.ImageField(default=None) 
    provider = models.ForeignKey(serviceProvider, on_delete=models.CASCADE, null=True)
    radius = models.FloatField(default=None)
    description= models.TextField(blank = True)
    hour_init = models.TimeField()
    hour_end = models.TimeField()
    picture1=models.ImageField(default=None, blank=True)    
    picture2=models.ImageField(default=None,blank=True) 
    picture3=models.ImageField(default=None, blank=True)    

```

This is the view.py function:

```auto
def addRubro (request):
    if request.method == 'POST': 
        if request.POST.get("tipo")=="2":
            proveedores=serviceProvider.objects.filter(user=request.POST.get("user"))
            if not proveedores:
                return HttpResponse("Bad")
            else:
                rubros=item.objects.filter(provider=proveedores.first())
                if len(rubros)<2:
                    new = item()
                    new.provider=proveedores.first()
                    new.radius=request.POST.get("radius")
                    new.description=request.POST.get("description")
                    new.hour_init=request.POST.get("hour_init")
                    new.hour_end=request.POST.get("hour_end") 
                    new.certificate=request.FILES.get("certificate")    
                    new.picture1=request.FILES.get("picture1")
                    new.picture2=request.FILES.get("picture2")
                    new.picture3=request.FILES.get("picture3")
                    new.save()  
                    return HttpResponse("Item loaded")

```

I have a model, which has 3 ImageField. When loading a new entry into the database, it may have some blank images, so the value is None. When the client request the model data entry, I get in the server side:

> ValueError: The ‘picture2’ attribute has no file associated with it.

How can I avoid it?

```auto
class item (models.Model):

    certificate=models.ImageField(default=None) 
    provider = models.ForeignKey(serviceProvider, on_delete=models.CASCADE, null=True)
    radius = models.FloatField(default=None)
    description= models.TextField(blank = True)
    hour_init = models.TimeField()
    hour_end = models.TimeField()
    picture1=models.ImageField(default=None, blank=True)    
    picture2=models.ImageField(default=None,blank=True) 
    picture3=models.ImageField(default=None, blank=True)    

```

This is the view function:

```auto
def addRubro (request):
    if request.method == 'POST': 
        if request.POST.get("tipo")=="2":
            proveedores=serviceProvider.objects.filter(user=request.POST.get("user"))
            if not proveedores:
                return HttpResponse("Bad")
            else:
                rubros=item.objects.filter(provider=proveedores.first())
                if len(rubros)<2:
                    new = item()
                    new.provider=proveedores.first()
                    new.radius=request.POST.get("radius")
                    new.description=request.POST.get("description")
                    new.hour_init=request.POST.get("hour_init")
                    new.hour_end=request.POST.get("hour_end") 
                    new.certificate=request.FILES.get("certificate")    
                    new.picture1=request.FILES.get("picture1")
                    new.picture2=request.FILES.get("picture2")
                    new.picture3=request.FILES.get("picture3")
                    new.save()  
                    return HttpResponse("Item loaded")

```

You can see that many times, a single image is sent, so the picture2 and picutre3 will be **None**.

Then when I try to send model information back to the client, I do it using this function

```auto
def requestRubros(request, tipo,user,rubro):
    if tipo=="2":
        proveedores=serviceProvider.objects.filter(user=user)
        if proveedores:
            rubro=item.objects.filter(provider=proveedores.first()).filter(items=rubro)
            if rubro:

                data = [{"radius": str(rubro.first().radius),
                "description": rubro.first().description,},
                
                {
                "hour_init": str(rubro.first().hour_init), "hour_end": str(rubro.first().hour_end)},
                
                {"certificate": "data:image/png;base64,"+base64.b64encode(rubro.first().certificate.read()).decode('ascii'),
                "picture1": "data:image/png;base64,"+(base64.b64encode(rubro.first().picture1.read())).decode('ascii'),
                "picture2": "data:image/png;base64,"+base64.b64encode(rubro.first().picture2.read()).decode('ascii'),
                "picture3": "data:image/png;base64,"+base64.b64encode(rubro.first().picture3.read()).decode('ascii')}]

                return JsonResponse(data, safe=False)

            else:
                return HttpResponse ("Bad data")
        else: 
            return HttpResponse ("Bad data")

```

---

<div class="post-metadata">

**Author:** ![KenWhitesell](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.djangoproject.com/kenwhitesell/32/280_2.png) [@KenWhitesell](https://forum.djangoproject.com/u/KenWhitesell)\
**Post date:** [April 11, 2021, 12:22am UTC](https://forum.djangoproject.com/t/read-imagefield-attribute-before-send-it/7469/2 "2021-04-11T00:22:53Z")

</div>

> [@julianov](#):
>
> The problem is in the imageField.read() when there is not a file to read. How can I solve it without check with if statment if there is or not a file?

I don’t understand why using an `if` statement isn’t an acceptable solution. It seems like the quickest, easiest, and most clear solution to me.

(Now, had you structured your models where the images were in a separate table with a FK to the `item` model, you could just iterate over the related items. But, since you’ve done it this way, you really don’t have too many other choices other than some type of conditional assignment.)

---

<div class="post-metadata">

**Author:** ![julianov](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.djangoproject.com/julianov/32/3502_2.png) [@julianov](https://forum.djangoproject.com/u/julianov)\
**Post date:** [April 11, 2021, 12:38pm UTC](https://forum.djangoproject.com/t/read-imagefield-attribute-before-send-it/7469/3 "2021-04-11T12:38:26Z")

</div>

The problem is that with if-elif, I have to have many lines of code depending on all the possibilities, of which images are None. I have 24 different combinations

```
if (datos.certificate.read()!=None and datos.picture1.read()!= None and datos.picture2.read()!= None and datos.picture3.read()!=None) :
                    {"certificate": "data:image/png;base64,"+base64.b64encode(datos.certificate.read()).decode('ascii'),
                    "picture1": "data:image/png;base64,"+(base64.b64encode(datos.picture1.read())).decode('ascii'),
                    "picture2": "data:image/png;base64,"+base64.b64encode(datos.picture2.read()).decode('ascii'),
                    "picture3": "data:image/png;base64,"+base64.b64encode(datos.picture3.read()).decode('ascii')}]
                    
elif (datos.certificate.read()!=None and datos.picture1.read()!= None and datos.picture2.read()!= None and datos.picture3.read()==None) :
                    {"certificate": "data:image/png;base64,"+base64.b64encode(datos.certificate.read()).decode('ascii'),
                    "picture1": "data:image/png;base64,"+(base64.b64encode(datos.picture1.read())).decode('ascii'),
                    "picture2": "data:image/png;base64,"+base64.b64encode(datos.picture2.read()).decode('ascii')}]
                    
elif (datos.certificate.read()==None and datos.picture1.read()!= None and datos.picture2.read()== None and datos.picture3.read()==None) :
                    {"certificate": "data:image/png;base64,"+base64.b64encode(datos.certificate.read()).decode('ascii'),
                    "picture1": "data:image/png;base64,"+(base64.b64encode(datos.picture1.read())).decode('ascii')}]
                    
elif (datos.certificate.read()==None and datos.picture1.read()!= None and datos.picture2.read()== None and datos.picture3.read()==None) :
                    {"certificate": "data:image/png;base64,"+base64.b64encode(datos.certificate.read()).decode('ascii')}]
                    
elif (datos.certificate.read()==None and datos.picture1.read()!= None and datos.picture2.read()!= None and datos.picture3.read()!=None) :
                    {"picture1": "data:image/png;base64,"+(base64.b64encode(datos.picture1.read())).decode('ascii'),
                    "picture2": "data:image/png;base64,"+base64.b64encode(datos.picture2.read()).decode('ascii'),
                    "picture3": "data:image/png;base64,"+base64.b64encode(datos.picture3.read()).decode('ascii')}]
                    
                    //and it keep going
```

---

<div class="post-metadata">

**Author:** ![KenWhitesell](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.djangoproject.com/kenwhitesell/32/280_2.png) [@KenWhitesell](https://forum.djangoproject.com/u/KenWhitesell)\
**Post date:** [April 11, 2021, 12:49pm UTC](https://forum.djangoproject.com/t/read-imagefield-attribute-before-send-it/7469/4 "2021-04-11T12:49:22Z")

</div>

No, you can do it more granularly than that. It’s one test for each image and a decision as to whether or not to add it to the dictionary you’re building.  
You’ll want to do something along the lines of:  
images = {}  
if “certificate image available”:  
images[‘certificate’] = “certificate image”  
if “image1 available”:  
images[‘image1’] = “image1”  
…  
and so on. One condition for each image.