Django - How to add data to a ManyToMany field model?

Question

I have the following models, view and template:

models.py:

class Batch(models.Model):
    material_id = models.ManyToManyField(AssetMetadata)
    user = models.ForeignKey(User)

    def __str__(self):
        return 'Batch_' + str(self.pk) + '_' + self.user.username

class AssetMetadata(models.Model):

    material_id = models.CharField(max_length=256, blank=True)
    series_title = models.CharField(max_length=256, blank=True)
    season_title = models.CharField(max_length=256, blank=True)
    season_number = models.IntegerField(default=0)
    episode_title = models.CharField(max_length=256, blank=True)
    episode_number = models.IntegerField(default=0)
    synopsis = models.TextField(max_length=1024, blank=True)
    ratings = models.CharField(max_length=256, blank=True)

    def __str__(self):
        return self.material_id

views.py:

def assets_in_repo(request):

    asset_list = AssetMetadata.objects.order_by('id').all()
    page = request.GET.get('page', 1)
    paginator = Paginator(asset_list, 50)

    try:
        assets = paginator.page(page)
    except PageNotAnInteger:
        assets = paginator.page(1)
    except EmptyPage:
        assets = paginator.page(paginator.num_pages)

    if request.method == 'POST':

        batch_list = request.POST.getlist('batch')
        print(batch_list)

    return render(request, 'assets_db/assets.html', {'assets': assets})

snippet from template:

<form method="post">{% csrf_token %}
    <input type="submit" value="Create Batch" align="right">
    <table class="table table-striped" id="myTable">
        <tr>
            <th>ID</th>
            <th>Material ID</th>
            <th>Series Title</th>
            <th>Season Tile</th>
            <th>Season Number</th>
            <th>Episode Title</th>
            <th>Episode Number</th>
            <th>Create Batch</th>
        </tr>
        {%  for i in assets %}<tr>
            <td>{{i.pk}}</td>
            <td><a href="/repo/{{ i.id}}">{{i.material_id}}</a></td>
            <td>{{i.series_title}}</td>
            <td>{{i.season_title}}</td>
            <td>{{i.season_number}}</td>
            <td>{{i.episode_title}}</td>
            <td>{{i.episode_number}}</td>
            <td>
                <input type="checkbox" name="batch" value="{{i.pk}}">
            </td>
        </tr>{% endfor %}
    </table>
    </form>

I am trying to get the data provided from the checkbox and save it in the Batch model.

The user selects assets to create a batch, the form returns the pk for these assetss in AssetMetadata and the selections are stored in a list create via batch_list = request.POST.getlist('batch'). I want to use the data stored in this list to create a new entry in Batch which then links to the asset pk in AssetMetadata.

I have been able to do this successfully in the Django admin page but i would ideally do this in teh view.

I have read https://docs.djangoproject.com/en/1.10/ref/models/relations/ and search stackoverflow but i am stumped as how to do this.

Answer 1

info = Batch.objects.create(season_title ='foo', .....)
info2= AssetMetadata.objects.create(material_id ='some')
info.material_id.add(info2)

try something like this