Create 021-server-defined-attributes.md

[vermakhushboo]

What does this PR do?

RFC to add optional server-defined attributes to user

Test Plan

(Write your test plan here. If you changed any code, please provide us with clear instructions on how you verified your changes work.)

Related PRs and Issues

(If this PR is related to any other PR or resolves any issue or related to any issue link all related PR and issues here.)

Have you read the Contributing Guidelines on issues?

(Write your answer here.)

[Meldiron]

Lets also have endpoint for listing them, so we don't need to hard-code then on Console. Its better to have config for it in Appwrite or library.

[Meldiron]

Let's have exact list of all internal attributes we will have

[stnguyen90]

it would also be good to clarify exactly what the behavior of each would be.

[byawitz]

The idea, in general, would help a lot on the part of Appwrite-console administrators (That can be a new market title 😉) and would help in setting pre-defined field structures for validations.

One way of expanding it would be to add a default callback using a function or other collection attributes.
This way the field value will auto-populate when no value was inserted.

Example 1 - Next appointment date.
In this example the default value would come from a function while passing the current document to that function

POST https://cloud.appwrite/v1/databases/:databaseId/collections/:collectionId/attributes/server
Content-Type: application/json
origin: https://localhost
{
  "id"      : "next_appointment",
  "type"    : "datetime",
  "format"  : "",
  "size"    : 0,
  "required": false,
  "default" : "[FUNCTION_ID]",
  "array"   : false,
  "filters" : []
}

Then, the function would run when the default value is empty, something like 👇, for example.

module.exports = async (context) => {
  try {
    // Set another appointment in 90 days.
    const next = new Date(+new Date() + (84600 * 90 * 1000));
    
    return context.res.json({ value: next });
  } catch (e) {
    return context.res.json({ value: '' });
  }
};

Example 2 - Adding search attribute
In this example the default value would come from the rest of the fields while each %*% variable is an attribute name in the current collection

POST https://cloud.appwrite/v1/databases/:databaseId/collections/:collectionId/attributes/server
Content-Type: application/json
origin: https://localhost
{
  "id"      : "search",
  "type"    : "string",
  "format"  : "",
  "size"    : 512,
  "required": false,
  "default" : "%name% %email% %address% %country% %phone%",
  "array"   : false,
  "filters" : []
}

[stnguyen90]

Suggested change

	* Relevant Issues: N/A
	* Relevant Issues:
	* https://github.com/appwrite/appwrite/issues/3623

[stnguyen90]

We do updates at the utopia-php/database level as well so we might need to do it there instead. For example, updatedAt and createdAt are handled in utopia: https://github.com/utopia-php/database/blob/4199fe8f00f4e181c7782c4a6862845d591c1f03/src/Database/Database.php#L3050-L3051

[stnguyen90]

it would also be good to clarify exactly what the behavior of each would be.

[jasonetorres]

👀👀🔥 definitely checking this out