This post is a catalogue of (almost) every single error I fought through while following along the Week 5 tutorial lecture to implement the chat room functions using DynamoDB.

• The errors are listed in chronological order, so it is possible that other campers met with one of the errors listed here might be greeted by other errors in a similar order.

• This post is currently evolving to update all the solution to every single error listed here. I hope it helps.

Error

• On Messages page, the individual messages are not showing in the chat room. (Disclaimer: as of writing this blog post (May 14, 2023), I have NOT earned the red squad badge. It's just my imagination)

Error lists

• UnboundLocalError: local variable 'ddb' referenced before assignment

• botocore.errorfactory.ResourceNotFoundException: Cannot do operations on a non-existent table

• psycopg_pool.PoolTimeout: couldn't get a connection after 30.0 sec

• botocore.errorfactory.ResourceInUseException: An error occurred (ResourceInUseException) when calling the CreateTable operation: Cannot create preexisting table

• An error occurred (ResourceNotFoundException) when calling the DeleteTable operation: Requested resource not found: Table: cruddur-messages not found

• botocore.exceptions.EndpointConnectionError: Could not connect to the endpoint URL: "http://localhost:8000/"

• [RESOLVED] 🔗NameError: name 'MessageGroups' is not defined

• ValidationException - when calling the Query operation: Value provided in ExpressionAttributeValues unused in expressions: keys: {:year}

• psycopg.OperationalError: consuming input failed: EOF detected

• NameError: name 'extract_access_token' is not defined

• flask_awscognito.exceptions.TokenVerifyError: Token is expired

• AttributeError: 'db' object has no attribute 'extract_access_token'

• WEM Error - Conversation content does not display when clicking on message group.

• TypeError: 'NoneType' object is not subscriptable

• 401 Unauthorized - NOT fetch error

update_cognito_user_ids

• TypeError: unhashable type: 'dict' (1)

• SOLVED - return model (1)

1:08:43 Reverse sorting messages

• KeyError: 'credential_provider' (1)

Create message

• TypeError: Cannot set property json of #<Object> which has only a getter (1)

• TypeError: CreateMessage.run() missing 2 required positional arguments: 'user_sender_handle' and 'user_receiver_handle' (1)

After creating new apis that create new message groups

• When trying to create a new message group (chat room) by calling the api with a username:

  • Not showing the same behaviour as Andrew’s

• botocore.errorfactory.ResourceNotFoundException: Requested resource not found (1)

• TypeError: ddb.list_message_groups() missing 1 required positional argument: 'current_user_uuid'

• TypeError: ddb.create_message() missing 1 required positional argument: 'table_name'

• botocore.exceptions.ParamValidationError: Parameter validation failed:

Conversation is displayed across different chat rooms

• Data is there (on AWS DynamoDB server). It's just NOT displaying on the webpage.

  • Need to verify...:

    • Is the app attempting to first "FETCH" the data? → Attempting to talk to the DB at all?

    • If yes, then where is it breaking so it fails to display it?

    • If not, then there is no link existing between the processes that make the data travel to the frontend. Where is it?