FR: arrayunion in update document (firestore)

[irux]

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• For issues or feature requests related to the code in this repository
  file a Github issue.
  • If this is a feature request make sure the issue title starts with "FR:".
• For general technical questions, post a question on StackOverflow
  with the firebase tag.
• For general Firebase discussion, use the firebase-talk
  google group.
• For help troubleshooting your application that does not fall under one
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  Firebase support channel.

[REQUIRED] Step 2: Describe your environment

• Operating System version: Windows 10
• Firebase SDK version: ??
• Library version: 2.13.0
• Firebase Product: Firestore (auth, database, storage, etc)

[REQUIRED] Step 3: Describe the problem

I would like to do a array update in a collection and not replacing what it has and only join with the new value

Relevant Code:

db.collection("users").document(id).update({"myArray":["value to join"]})

[hiranya911]

This is supported in Node.js but not in Python. It will be added in a future release.

[raytso]

Any updates on this? It’s already in the tutorial docs.

[schmidt-sebastian]

CC @crwilcox

[busunkim96]

This has been supported since the v1beta1 release of the google-cloud-firestore.

• https://firebase.google.com/docs/firestore/manage-data/add-data#update_elements_in_an_array
• https://googleapis.github.io/google-cloud-python/latest/firestore/transforms.html?highlight=arrayunion#module-google.cloud.firestore_v1beta1.transforms

[irux]

OK! it seems like this library doesn't support the new v1beta1 package and it imports the old firestore client. should we write a new issue for that feature ?

[busunkim96]

The library will default to v1, but you can import explicitly from v1beta1 to use this feature.

from google.cloud import firestore
from google.cloud.firestore_v1beta1 import ArrayUnion

def update_doc_array():
    db = firestore.Client()
    # [START fs_update_doc_array]
    city_ref = db.collection(u'cities').document(u'DC')

    # Atomically add a new region to the 'regions' array field.
    city_ref.update({u'regions': ArrayUnion([u'greater_virginia'])})

    # // Atomically remove a region from the 'regions' array field.
    city_ref.update({u'regions': ArrayRemove([u'east_coast'])})
    # [END fs_update_doc_array]
    city = city_ref.get()
    print(u'Updated the regions field of the DC. {}'.format(city.to_dict()))

This is from the firestore snippets.py.

[hiranya911]

This should be supported now (at least since v3 release). Please let us know if you run into any problems.