The Media Platform Package
The first part of this tutorial focuses on the media platform package, which will contain the free_trial function that users can call to subscribe to the free trial option. The free_trial function will be called by the user's signed transaction, which will be sponsored by the Gas Station server.
First, create a new Move project called sponsored_transactions, and add the following code to the sources/sponsored_transactions.move file:
sponsored_transactions_packages/sources/sponsored_transactions.move
loading...
When you publish the package, init will be called, creating a SubscriptionManager shared object and transferring the Publisher object to the sender. The Publisher object is used to ensure that only the publisher can call the publish function.
iota client publish
View Publish Output
UPDATING GIT DEPENDENCY https://github.com/iotaledger/iota.git
INCLUDING DEPENDENCY Iota
INCLUDING DEPENDENCY MoveStdlib
BUILDING sponsored_transactions_packages
Successfully verified dependencies on-chain against source.
╭──────────────────────────────────────────────────────────────────────────────────────────────────────────────╮
│ Transaction Data │
├──────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
│ Sender: 0xbf293ced2593118cd231f107f341bb1ad9db39cd0497bff29d355730cf4e2bc2 │
│ Gas Owner: 0xbf293ced2593118cd231f107f341bb1ad9db39cd0497bff29d355730cf4e2bc2 │
│ Gas Budget: 26175600 NANOS │
│ Gas Price: 1000 NANOS │
│ Gas Payment: │
│ ┌── │
│ │ ID: 0x39ea9a3f9889c1fc3d79d63d97ae293a74859d0ce0b876c090211471e37067bb │
│ │ Version: 5133 │
│ │ Digest: FUX3cb9c2Wovk4ELYM1NCmSukV59PRgZzAGZZ14DF641 │
│ └── │
│ │
│ Transaction Kind: Programmable │
│ ╭──────────────────────────────────────────────────────────────────────────────────────────────────────────╮ │
│ │ Input Objects │ │
│ ├──────────────────────────────────────────────────────────────────────────────────────────────────────────┤ │
│ │ 0 Pure Arg: Type: address, Value: "0xbf293ced2593118cd231f107f341bb1ad9db39cd0497bff29d355730cf4e2bc2" │ │
│ ╰──────────────────────────────────────────────────────────────────────────────────────────────────────────╯ │
│ ╭─────────────────────────────────────────────────────────────────────────╮ │
│ │ Commands │ │
│ ├─────────────────────────────────────────────────────────────────────────┤ │
│ │ 0 Publish: │ │
│ │ ┌ │ │
│ │ │ Dependencies: │ │
│ │ │ 0x0000000000000000000000000000000000000000000000000000000000000002 │ │
│ │ │ 0x0000000000000000000000000000000000000000000000000000000000000001 │ │
│ │ └ │ │
│ │ │ │
│ │ 1 TransferObjects: │ │
│ │ ┌ │ │
│ │ │ Arguments: │ │
│ │ │ Result 0 │ │
│ │ │ Address: Input 0 │ │
│ │ └ │ │
│ ╰─────────────────────────────────────────────────────────────────────────╯ │
│ │
│ Signatures: │
│ LDs5QIxx4VyYOJkswnNtDSSCYnzSJcT1Y4angwSU2F+Q4xv3wH14/ftCzwDRkEkhR2l/JxFvAnAEzLzc8jUcDg== │
│ │
╰──────────────────────────────────────────────────────────────────────────────────────────────────────────────╯
╭───────────────────────────────────────────────────────────────────────────────────────────────────╮
│ Transaction Effects │
├───────────────────────────────────────────────────────────────────────────────────────────────────┤
│ Digest: HMNX7GPsiMpCTBw7UTxWsc7afDC4BhKLuJMv8sWev1xh │
│ Status: Success │
│ Executed Epoch: 46 │
│ │
│ Created Objects: │
│ ┌── │
│ │ ID: 0x1470020d52099b5181ede006875eb4d5f4e95745c405cd6d0a202c4734f4d280 │
│ │ Owner: Account Address ( 0xbf293ced2593118cd231f107f341bb1ad9db39cd0497bff29d355730cf4e2bc2 ) │
│ │ Version: 5134 │
│ │ Digest: 42AvDhg1F9tDkW5pfFR2AYHcjBQLa787YxF9XbAWdfjb │
│ └── │
│ ┌── │
│ │ ID: 0x2069e91c8333350bdf6bbd2991266ad33992757db7af48291adb58e7a5b0e1aa │
│ │ Owner: Immutable │
│ │ Version: 1 │
│ │ Digest: 9BjRWZpBPZYaKxU4GxSJzTD4AmWi6L1pcbb8AwKHFtEJ │
│ └── │
│ ┌── │
│ │ ID: 0x995919215d7d3282e92446436921ea850d14df9fa98eb5c84a84e325519e0875 │
│ │ Owner: Account Address ( 0xbf293ced2593118cd231f107f341bb1ad9db39cd0497bff29d355730cf4e2bc2 ) │
│ │ Version: 5134 │
│ │ Digest: AVsPGE2FYNtron4CSrfpiCkaV7rNuviEZ4SWitemsgUg │
│ └── │
│ ┌── │
│ │ ID: 0xb05236e6ca067e3fa114bab1558f35e44097e0078aa681761faa62220858a176 │
│ │ Owner: Shared( 5134 ) │
│ │ Version: 5134 │
│ │ Digest: JDZ8KD6sHapkZdrLCutM9jRd9MR7jDVZc3U61bLrdRM2 │
│ └── │
│ Mutated Objects: │
│ ┌── │
│ │ ID: 0x39ea9a3f9889c1fc3d79d63d97ae293a74859d0ce0b876c090211471e37067bb │
│ │ Owner: Account Address ( 0xbf293ced2593118cd231f107f341bb1ad9db39cd0497bff29d355730cf4e2bc2 ) │
│ │ Version: 5134 │
│ │ Digest: 5W22iUDDMKdVnEeeLiDf2zKWzZqz7BbsjazTyKyhsb22 │
│ └── │
│ Gas Object: │
│ ┌── │
│ │ ID: 0x39ea9a3f9889c1fc3d79d63d97ae293a74859d0ce0b876c090211471e37067bb │
│ │ Owner: Account Address ( 0xbf293ced2593118cd231f107f341bb1ad9db39cd0497bff29d355730cf4e2bc2 ) │
│ │ Version: 5134 │
│ │ Digest: 5W22iUDDMKdVnEeeLiDf2zKWzZqz7BbsjazTyKyhsb22 │
│ └── │
│ Gas Cost Summary: │
│ Storage Cost: 24175600 NANOS │
│ Computation Cost: 1000000 NANOS │
│ Storage Rebate: 980400 NANOS │
│ Non-refundable Storage Fee: 0 NANOS │
│ │
│ Transaction Dependencies: │
│ 63X49x2QuuYNduExZWoJjfXut3s3WDWZ7Tr7nXJu32ZT │
│ HWkNmvRAAGgj4qh2B4X16CqQ829TQmSmexdDzFekRRTH │
╰───────────────────────────────────────────────────────────────────────────────────────────────────╯
╭─────────────────────────────╮
│ No transaction block events │
╰─────────────────────────────╯
╭───────────────────────────────────────────────────────────────────────────── ─────────────────────────────────────────────────────────────╮
│ Object Changes │
├──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
│ Created Objects: │
│ ┌── │
│ │ ObjectID: 0x1470020d52099b5181ede006875eb4d5f4e95745c405cd6d0a202c4734f4d280 │
│ │ Sender: 0xbf293ced2593118cd231f107f341bb1ad9db39cd0497bff29d355730cf4e2bc2 │
│ │ Owner: Account Address ( 0xbf293ced2593118cd231f107f341bb1ad9db39cd0497bff29d355730cf4e2bc2 ) │
│ │ ObjectType: 0x2::package::Publisher │
│ │ Version: 5134 │
│ │ Digest: 42AvDhg1F9tDkW5pfFR2AYHcjBQLa787YxF9XbAWdfjb │
│ └── │
│ ┌── │
│ │ ObjectID: 0x995919215d7d3282e92446436921ea850d14df9fa98eb5c84a84e325519e0875 │
│ │ Sender: 0xbf293ced2593118cd231f107f341bb1ad9db39cd0497bff29d355730cf4e2bc2 │
│ │ Owner: Account Address ( 0xbf293ced2593118cd231f107f341bb1ad9db39cd0497bff29d355730cf4e2bc2 ) │
│ │ ObjectType: 0x2::package::UpgradeCap │
│ │ Version: 5134 │
│ │ Digest: AVsPGE2FYNtron4CSrfpiCkaV7rNuviEZ4SWitemsgUg │
│ └── │
│ ┌── │
│ │ ObjectID: 0xb05236e6ca067e3fa114bab1558f35e44097e0078aa681761faa62220858a176 │
│ │ Sender: 0xbf293ced2593118cd231f107f341bb1ad9db39cd0497bff29d355730cf4e2bc2 │
│ │ Owner: Shared( 5134 ) │
│ │ ObjectType: 0x2069e91c8333350bdf6bbd2991266ad33992757db7af48291adb58e7a5b0e1aa::sponsored_transactions_packages::SubscriptionManager │
│ │ Version: 5134 │
│ │ Digest: JDZ8KD6sHapkZdrLCutM9jRd9MR7jDVZc3U61bLrdRM2 │
│ └── │
│ Mutated Objects: │
│ ┌── │
│ │ ObjectID: 0x39ea9a3f9889c1fc3d79d63d97ae293a74859d0ce0b876c090211471e37067bb │
│ │ Sender: 0xbf293ced2593118cd231f107f341bb1ad9db39cd0497bff29d355730cf4e2bc2 │
│ │ Owner: Account Address ( 0xbf293ced2593118cd231f107f341bb1ad9db39cd0497bff29d355730cf4e2bc2 ) │
│ │ ObjectType: 0x2::coin::Coin<0x2::iota::IOTA> │
│ │ Version: 5134 │
│ │ Digest: 5W22iUDDMKdVnEeeLiDf2zKWzZqz7BbsjazTyKyhsb22 │
│ └── │
│ Published Objects: │
│ ┌── │
│ │ PackageID: 0x2069e91c8333350bdf6bbd2991266ad33992757db7af48291adb58e7a5b0e1aa │
│ │ Version: 1 │
│ │ Digest: 9BjRWZpBPZYaKxU4GxSJzTD4AmWi6L1pcbb8AwKHFtEJ │
│ │ Modules: sponsored_transactions_packages │
│ └── │
╰──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯
╭───────────────────────────────────────────────────────────────────────────────────────────────────╮
│ Balance Changes │
├───────────────────────────────────────────────────────────────────────────────────────────────────┤
│ ┌── │
│ │ Owner: Account Address ( 0xbf293ced2593118cd231f107f341bb1ad9db39cd0497bff29d355730cf4e2bc2 ) │
│ │ CoinType: 0x2::iota::IOTA │
│ │ Amount: -24195200 │
│ └── │
╰───────────────────────────────────────────────────────────────────────────────────────────────────╯
Take a look at the transaction digest and retrieve the SubscriptionManager shared object, which you will need to call the free_trial function.
Both subscribe and free_trial functions allow users to subscribe to a specific type of content, with the distinction that free_trial doesn't deduct coins from the user's balance.
info
The package implementation is oversimplified, as the main focus is the sponsored transactions workflow. In a real-world application, you would should:
- Use timestamps to track the subscription duration and automatically unsubscribe users after the trial period.
- Restrict the number of free trials a user can have.
This package contains the following functions:
subscribe: Allows a user to subscribe to a specific type of content.free_trial: Allows a user to subscribe to the free trial option.publish: Publishes content to the subscribers and trials. This function is only callable by the publisher.
And the following structs:
SubscriptionType: Enum representing subscription types.Content: Struct representing content.Subscribed: Event for subscriptions.SubscriptionManager: Struct encapsulating subscription and trial tables. This is used to manage subscriptions and trials.