joystream/testnets/acropolis/specification/runtime/members-module.md

Members Module: is not part of Acropolis spec, only kept for future purposes.

Table Of Contents

• Design
• Dependencies
• Name
• Concepts
• State
• Events
• Dispatchable Methods
  • buy_membership
  • change_member_about_text
  • change_member_avatar
  • change_member_handle
  • update_profile
  • add_screened_member
  • set_screening_authority
• Non-dispatchable Methods
  • is_active_member
  • lookup_member_id
  • lookup_account_by_member_id

Design

Motivation

The membership module is supposed to represent the current set of members on the platform, and manage corresponding rich profiles, as well as the entry of new members.

Membership

Each membership corresponds to an account, but not all accounts will have a membership. An account may only be associated with a single membership. A membership has a corresponding rich profile, including practical user facing information, such as a unique immutable handle, an avatar URI and a short descriptive text.

A membership can also be active or inactive.

Terms

A membership is established in the context of membership terms, which describe the price of admission and human readable conditions being agreed to. At any given time there may be a range of different terms available, and the set may change over time.

Adding members

A member can be introduced in two ways. Either way depends on the module either being open or closed for accepting new members.

The first way is for a member to simply pay for getting entry, with a reference to a given set of terms. In this case, the membership will have a reference to the terms under which it was established.

The second is for a screening authority, which is a designated account, to simply add the new member. In this case, the membership will have a reference to the screening authority.

Name

Membership

Dependencies

• Currency: An external currency module which supports altering balances and total issuance.

Concepts

• Profile: Describes core properties and status of a membership, like a unique handle and avatar URI. Is identified with unique integer identifier, called member id.

• PaidMembershipTerms: Terms for becoming a member, like price and terms. Is identified with a unique integer identifier called a paid terms id.

• UserInfo: Information required to establish a new profile.

State

• NextMemberId: Unique identifier for next member, should equal total number of members ever created.

• AccountIdByMemberId: Maps member id to an account id.

• MemberIdByAccountId: Maps account id to optional member id.

• MemberProfile: Maps member id to Profile of member.

• Handles: Maps handle to corresponding member id.

• NextPaidMembershipTermsId: Next paid membership terms id.

• PaidMembershipTermsById: Maps paid terms id to actual terms.

• ActivePaidMembershipTerms: Set of active paid term ids.

• NewMembershipsAllowed: Whether new memberships can currently be established.

• ScreeningAuthority: Optional account of screener.

• MinHandleLength, MaxHandleLength, MaxAvatarUriLength, MaxAboutTextLength: Mutable constraint variables

Events

• MemberRegistered: A member was registered with a given id and account.
• MemberUpdatedAboutText: A member, with given id, had text updated.
• MemberUpdatedAvatar: A member, with given id, had avatar URI updated.
• MemberUpdatedHandle: A member, with given id, had handle updated.

Dispatchable Methods

buy_membership

Payload

• paid_terms_id: Id of terms
• user_info: UserInfo

Description

Establish new membership through payment.

Errors

• Bad signature.
• New members not allowed.
• Account already associated with a membership.
• Role key cannot be used for membership.
• Paid terms id not active.
• Not enough balance to buy membership.
• Missing handle.
• Handle too short.
• Handle too long.
• Avatar URI too long.
• Handle occupied.

Side effects

Membership established

Precondition

NO_ERROR

Side effect(s)

• Currency has decreased primary account balance and total issuance by terms fee.
• MemberIdByAccountId extended.
• AccountIdByMemberId extended.
• MemberProfile extended with new profile created with payload values.
• Handles extended with handle.
• NextMemberId incremented.

Event(s)

• MemberRegistered for new member

change_member_about_text

Payload

• text: New about text

Description

Change about text on membership.

Errors

• Bad signature.
• No member id found for account id.
• Not primary account.
• Member profile not found.

Side effects

About text updated

Precondition

NO_ERROR

Side effect(s)

• The text of profile of member corresponding to origin account is set to truncated text

Event(s)

• MemberUpdatedAboutText

change_member_avatar

fill in

change_member_handle

fill in

update_profile

fill in

add_screened_member

fill in

set_screening_authority

fill in

Non-dispatchable Methods

is_active_member

fill in

lookup_member_id

fill in

lookup_account_by_member_id

fill in