UPGRADE.md

Upgrading from 1.x to 2.x

Passing database as option to the constructor is no longer supported, for this please use the MongoDB connection url.

// instead of
const options = {
  database: 'local'
};

const oplog = MongoOplog('mongodb://mydomain.com:27017', options);

// use like this
const oplog = MongoOplog('mongodb://mydomain.com:27017/local');

The tail method no longer return the oplog instance instead it returns a Promise.

// instead of
const oplog = MongoOplog(conn.oplog, { ns: 'test.posts' }).tail()
oplog.on('op', fn)

// use this
const oplog = MongoOplog(conn.oplog, { ns: 'test.posts' })
oplog.tail()
oplog.on('op', fn)

The tail, stop, destroy methods now return a more convenient Promise instance instead of the oplog object.

oplog.tail().then(stream => {
  console.log('tailing')
}).catch(err => console.log(err))

oplog.stop().then(() => {
  console.log('tailing stopped')
}).catch(err => console.log(err))

oplog.destroy().then(() => {
  console.log('oplog connection destroyed')
}).catch(err => console.log(err))

Please note that callbacks are still supported for now, in the feature this can change and we might drop callback support in favor of only promises.

Upgrading from 0.x to 1.x

The constructor does no longer support new, just call the constructor as a regular function.

// instead of
var oplog = new MongoOplog(uri);

// use this
var oplog = MongoOplog(uri);

The constructor does no longer support 3 arguments (uri, ns, options) but only two (uri, options).

// instead of
var options = {
  database: 'local'
};

var oplog = MongoOplog(uri, 'test.posts', options);

// use like this
var options = {
  ns: 'test.posts',
  database: 'local'
};

var oplog = MongoOplog(uri, options);

Use stop or destroy, the first will stop and destroy the tailing cursor and the second will destroy cursor and database connection disconnecting from server.

oplog.destroy(function(){
  console.log('destroyed');
});

Use the ignore flag to pause and resume oplog events.

oplog.ignore = true; // to pause
oplog.ignore = false // to resume

oplog.filter no longer has a ns method, you need to pass the namespace when invoking the filter method.

// instead of
oplog.filter()
.ns('*.posts')
.on('op', function(doc){
  console.log(doc);
});

// use this
oplog.filter('*.posts')
.on('op', function(doc){
  console.log(doc);
});

Filter object now has a destroy method.

filter.destroy(function(){
  console.log('destroyed');
});

Filters also support the ignore flag to pause and resume filter events.

filter.ignore = true; // to pause
filter.ignore = false; // to resume