## @aeternity/aepp-sdk/es/tx/builder/helpers JavaScript-based Transaction builder helper function's **Example** ```js import TxBuilderHelper from '@aeternity/aepp-sdk/es/tx/builder/helpers' ``` * [@aeternity/aepp-sdk/es/tx/builder/helpers](#module_@aeternity/aepp-sdk/es/tx/builder/helpers) * [exports.buildContractId(ownerId, nonce)](#exp_module_@aeternity/aepp-sdk/es/tx/builder/helpers--exports.buildContractId) ⇒ `string` ⏏ * [exports.formatSalt(salt)](#exp_module_@aeternity/aepp-sdk/es/tx/builder/helpers--exports.formatSalt) ⇒ `string` ⏏ * [exports.decode(data, type)](#exp_module_@aeternity/aepp-sdk/es/tx/builder/helpers--exports.decode) ⇒ `Buffer` ⏏ * [exports.encode(data, type)](#exp_module_@aeternity/aepp-sdk/es/tx/builder/helpers--exports.encode) ⇒ `String` ⏏ * [exports.writeId(hashId)](#exp_module_@aeternity/aepp-sdk/es/tx/builder/helpers--exports.writeId) ⇒ `Buffer` ⏏ * [exports.readId(buf)](#exp_module_@aeternity/aepp-sdk/es/tx/builder/helpers--exports.readId) ⇒ `String` ⏏ * [exports.writeInt(val)](#exp_module_@aeternity/aepp-sdk/es/tx/builder/helpers--exports.writeInt) ⇒ `Buffer` ⏏ * [exports.readInt(buf)](#exp_module_@aeternity/aepp-sdk/es/tx/builder/helpers--exports.readInt) ⇒ `String` ⏏ * [exports.buildPointers(pointers)](#exp_module_@aeternity/aepp-sdk/es/tx/builder/helpers--exports.buildPointers) ⇒ `Array` ⏏ * [exports.readPointers(pointers)](#exp_module_@aeternity/aepp-sdk/es/tx/builder/helpers--exports.readPointers) ⇒ `Array` ⏏ ### exports.buildContractId(ownerId, nonce) ⇒ `string` ⏏ Build a contract public key **Kind**: Exported function **Returns**: `string` - Contract public key | Param | Type | Description | | --- | --- | --- | | ownerId | `string` | The public key of the owner account | | nonce | `number` | the nonce of the transaction | ### exports.formatSalt(salt) ⇒ `string` ⏏ Format the salt into a 64-byte hex string **Kind**: Exported function **Returns**: `string` - Zero-padded hex string of salt | Param | Type | | --- | --- | | salt | `number` | ### exports.decode(data, type) ⇒ `Buffer` ⏏ Decode data using the default encoding/decoding algorithm **Kind**: Exported function **Returns**: `Buffer` - Buffer of decoded Base58check or Base64check data | Param | Type | Description | | --- | --- | --- | | data | `string` | An encoded and prefixed string (ex tx_..., sg_..., ak_....) | | type | `string` | Prefix of Transaction | ### exports.encode(data, type) ⇒ `String` ⏏ Encode data using the default encoding/decoding algorithm **Kind**: Exported function **Returns**: `String` - Encoded string Base58check or Base64check data | Param | Type | Description | | --- | --- | --- | | data | `Buffer` \| `String` | An decoded data | | type | `string` | Prefix of Transaction | ### exports.writeId(hashId) ⇒ `Buffer` ⏏ Utility function to create and _id type **Kind**: Exported function **Returns**: `Buffer` - Buffer Buffer with ID tag and decoded HASh | Param | Type | Description | | --- | --- | --- | | hashId | `string` | Encoded hash | ### exports.readId(buf) ⇒ `String` ⏏ Utility function to read and _id type **Kind**: Exported function **Returns**: `String` - Encoided hash string with prefix | Param | Type | Description | | --- | --- | --- | | buf | `Buffer` | Data | ### exports.writeInt(val) ⇒ `Buffer` ⏏ Utility function to convert int to bytes **Kind**: Exported function **Returns**: `Buffer` - Buffer Buffer from number(BigEndian) | Param | Type | Description | | --- | --- | --- | | val | `Number` \| `String` \| `BigNumber` | Value | ### exports.readInt(buf) ⇒ `String` ⏏ Utility function to convert bytes to int **Kind**: Exported function **Returns**: `String` - Buffer Buffer from number(BigEndian) | Param | Type | Description | | --- | --- | --- | | buf | `Buffer` | Value | ### exports.buildPointers(pointers) ⇒ `Array` ⏏ Helper function to build pointers for name update TX **Kind**: Exported function **Returns**: `Array` - Serialized pointers array | Param | Type | Description | | --- | --- | --- | | pointers | `Array` | Array of pointers ([ { key: 'account_pubkey', id: 'ak_32klj5j23k23j5423l434l2j3423'} ]) | ### exports.readPointers(pointers) ⇒ `Array` ⏏ Helper function to read pointers from name update TX **Kind**: Exported function **Returns**: `Array` - Deserialize pointer array | Param | Type | Description | | --- | --- | --- | | pointers | `Array` | Array of pointers ([ { key: 'account_pubkey', id: 'ak_32klj5j23k23j5423l434l2j3423'} ]) |