Global topic id standard for definition of configuration and formatting.

[HGraphPunks]

After much discussion in the previous threads, I've decided to make a new discussion with the finalized topic id idea to present a clear story and thought process. Link to old discussion here

I'm proposing that each Topic Id utilizes the memo field to define the standard type, the configuration file, and the header. I believe a simple JSONLD structure that defines the sequence numbers of each is the most flexible and scalable solution.

Example memo field on a topic id:

{ 
   "content-type":"JSON-LD" //  required
   "schema": "dao-vote", // required
   "schema-ext":"ranked-choice" // optional
   "config": "seq[1,3]", // required if schema is set to custom 
   "header": "seq[4,9]", // optional 
}

In the above example,

1. header is defined by sequence numbers on the topic id. This allows both the topic id to contain the data in messages that can also be updated by updating the memo field. The value of header defines the sequence number fo the beginning and end of the header. More often than not, header will be one seq number. Only if the characters extend to multiple messages should there be a second value in the array. The second value is the end of the messages that define the header data.

The data of the header is required to be sequential in the messages so it make be stiched and parsed in order of the messages.

2. schema should define the standard being used for the formatting of the data. one of the standards in this HIP for the formats that are open to be read by the public. This field can be set to custom for instances that the data isn't in any standard set in this HIP.

If schema is set to custom, then "config" is required in the topic id memo's JSONLD and should point to sequence numbers where the types are defined for external reading. This enables updating the config through updating the memo if the data is needed to change.

Below is an example of a topic id message that defines a configuration for two types of objects to expect on the topic id, highscore and achievement.

setTypes would always be an array and defined objects that represent objects that can be expected to be found on messages. This format is JSON-LD but these config files would be in the format as defined in content-type in the topid id memo field

The objects only required field will be type. This is the linking attribute that allows anyone reading the Id to match the structure of the object in the config, to the used type in the messages and knowing what values to expect.

 {
        "type": "config",
        “setTypes”:[
	    {
		    “type”: "highscore”,
		    "playerId": "string",
		    "playerName": "string",
	            "accountId": "string",
                    "score": "integer",
	    },
	    {
		    "type": "achievement",
		    "playerId": "string",
		    "playerName": "string",
	            "accountId": "string",
                    "achievementId": "integer",
	    },
        ]
}

To do:
I'm working on finalizing the specific data models that would be set as standards in this HIP that don't require a config file. It's possible that this HIP would define the config method alone and another update could be added to determine the initial supported data format standards.

[mgarbs]

I've said this to you before, but I'll say it again. I like this hip a lot. What a great way to describe topic contents. It's very natural and makes a great deal of sense. Building on the examples piece of this hip, here's a schema for a Hypothetical Thread / Discussion:

{
    "content-type": "JSON-LD",
    "schema": "thread",
    "config": "seq[1,1]",
    "header": "seq[2,2]"
}

Config:

{
    "type": "config",
    "setTypes": [
        {
            "type": "thread",
            "title": "string",
            "author": "string",
            "authorAccount": "string",
            "timestamp": "datetime",
            "content": "string",
            "upvotes": "integer",
            "downvotes": "integer"
            "tags": ["string"]
        },
        {
            "type": "reply",
            "author": "string",
            "authorAccount": "string",
            "timestamp": "datetime",
            "content": "string",
            "upvotes": "integer",
            "downvotes": "integer"
        }
    ]
}

header:

{
    "type": "header",
    "title": "Thread / Discussion on HCS",
    "description": "A log of threads and discussions utilizing Hedera Consensus Service."
}