[API] Tags is a Required Field for POST-ing a Resource

[BethanyG]

Currently, the model for Resouces has tags = TaggableManager(blank=True), and while this will allow a blank tags field, it will not allow a poster to omit the tags field from the POST.

This is not desirable, and we will need to consider if we would like to write code to apprehend the incoming POST to check for the missing field and supply it , as opposed to throwing a "this field is required" error...or otherwise research how to make the code more flexible so that the field is not required.

[lpatmo]

From a React perspective, I think this is fine! That is, we can be explicit about requiring a tags field in the form to submit a resource. The other conclusion is that every endpoint will need a tags field supplied (and a tags field in the UI), right?

Are there other scenarios I'm missing?

[billglover]

I think we need to remove the requirement for an empty array. Expected behaviour when calling an API is that optional fields do not need to be provided. It would be unusual to require an array but not require it to contain any values.

It could be worked around in react, but any other consumer of the API would also have to work around this issue.

[BethanyG]

Color me totally relieved that this is an area where Django/DRF made it easy. Turns out, I needed to supply a default value that triggers a blank field save. Here are the docs I worked from, and here is the code change needed:

class ResourceSerializer(TagSerializer, serializers.ModelSerializer):

    #adding default="" here causes the field to not be required by DRF
    tags = TagsSerializerField(model_field='tags', default='')
    media_type = serializers.SerializerMethodField()
    user = UserSerializer(read_only=True)

     ...

Currently working in a branch to try several of the proposed tag changes and fixes, so this will be part of an upcoming PR...but if it's making you crazy, you can patch your code with the above, and that should take care of it.

[billglover]

This is an awesome find, nice one!