TriggerManagerImpl

Internal Experimental

Implements

• TriggerManager

Constructors

new TriggerManagerImpl()

new TriggerManagerImpl(options): TriggerManagerImpl

Experimental

Parameters

Parameter	Type
options	TriggerManagerImplOptions

Returns

TriggerManagerImpl

Methods

cleanupResources()

cleanupResources(): Promise<void>

Experimental

Returns

Promise<void>

---

createDiffTrigger()

createDiffTrigger(options): Promise<() => Promise<void>>

Experimental

Parameters

Parameter	Type
options	CreateDiffTriggerOptions

Returns

Promise<() => Promise<void>>

A callback to remove the trigger and drop the destination table.

Example

const dispose = await database.triggers.createDiffTrigger({
  source: 'lists',
  destination: 'ps_temp_lists_diff',
  columns: ['name'],
  when: {
   [DiffTriggerOperation.INSERT]: 'TRUE',
   [DiffTriggerOperation.UPDATE]: 'TRUE',
   [DiffTriggerOperation.DELETE]: 'TRUE'
  }
});

Implementation of

TriggerManager.createDiffTrigger

---

dispose()

dispose(): void

Experimental

Returns

void

---

trackTableDiff()

trackTableDiff(options): Promise<TriggerRemoveCallback>

Experimental

Parameters

Parameter	Type
options	TrackDiffOptions

Returns

Promise<TriggerRemoveCallback>

A callback to cleanup the trigger and stop tracking changes.

NB: The triggers created by this method might be invalidated by AbstractPowerSyncDatabase#updateSchema calls. These triggers should manually be dropped and recreated when updating the schema.

Example

 const dispose = database.triggers.trackTableDiff({
       source: 'todos',
       columns: ['list_id'],
       when: {
         [DiffTriggerOperation.INSERT]: sanitizeSQL`json_extract(NEW.data, '$.list_id') = ${sanitizeUUID(someIdVariable)}`
       },
       onChange: async (context) => {
         // Fetches the todo records that were inserted during this diff
         const newTodos = await context.withDiff<Database['todos']>(`
           SELECT
             todos.*
           FROM
             DIFF
             JOIN todos ON DIFF.id = todos.id
         `);

         // Process newly created todos
       },
       hooks: {
         beforeCreate: async (lockContext) => {
           // This hook is executed inside the write lock before the trigger is created.
           // It can be used to synchronize the current state of the table with processor logic.
           // Any changes after this callback are guaranteed to trigger the `onChange` handler.

           // Read the current state of the todos table
           const currentTodos = await lockContext.getAll<Database['todos']>(
             `
               SELECT
                 *
               FROM
                 todos
               WHERE
                 list_id = ?
             `,
             ['123']
           );

           // Process existing todos
         }
       }
     });

Implementation of

TriggerManager.trackTableDiff

---

updateDefaults()

updateDefaults(config): void

Experimental

Parameters

Parameter	Type
config	TriggerManagerImplConfiguration

Returns

void