@becual/pg-notify

pg-notify

Configure and subscribe to Postgres Notify automatically for a given set of tables.

| Param | Type | Default | Description |
| --- | --- | --- | --- |
| client | object | | node-postgres Client instance |
| configObject | object | | Configuration object |
| configObject.schema | string | "public" | Name of the schema where the tables exists. |
| configObject.functionName | string | "notify_table_change" | Name of the function to use notify. |
| configObject.channelName | string | "notify_table_change_channel" | Name of the channel where the function will notify. |

* pg-notify
* ~Subscribe to all database events of a given list of tables(tables) ⇒ Promise
* ~Create the functions and triggers to configure pg-notify.(tables) ⇒ Promise

$3

Kind: inner method of pg-notify
Returns: Promise - a promise wich resolves an NodeJS EventEmitter

| Param | Type | Description |
| --- | --- | --- |
| tables | Array.<string> | An array of table names to listen |

Example
``js
const { Client } = require('pg');
const pgNotify = require('@becual/pg-notify');

let eventHandler = evt => {
console.log(JSON.stringify(evt, null, 4));
};

(async () => {
// Use your connection string
const client = new Client({ connectionString: process.env.PG_CONNECTION_STRING });

// Choose your tables to listen
const tables = ['customer', 'order_detail'];

try {
// Connect client
await client.connect();

// By default schema is public
const sub = await pgNotify(client, {schema: 'mySchema'}).subscribe(tables);

// Listen for changes
sub.on('INSERT', eventHandler);
sub.on('UPDATE', eventHandler);
sub.on('DELETE', eventHandler);
}
catch(error) {
console.log(error.message);
}
finally {
await client.end();
}
})();
`


$3

Kind: inner method of pg-notify
Returns: Promise - A promise that will implement the pg-notify config.

| Param | Type | Description |
| --- | --- | --- |
| tables | Array.<string> | The list of tables to create pg notify configuration. |

Example
`js
const { Client } = require('pg');
const pgNotify = require('@becual/pg-notify');

(async () => {

const client = new Client({ connectionString: process.env.PG_CONNECTION_STRING });
const tableList = ['customer', 'order_detail'];

try {
// Try to generate configuration
await client.connect();
await pgNotify(client, {schema: 'mySchema'}).config(tableList);
}
catch(error) {
// Show errors
console.log(error.message);
}
finally {
// Close connection
await client.end();
}
})();
``