changes

A consistent, fault tolerant CouchDB _changes listener with pre-fetch support.

Usage

`` js
var Changes = require('changes');

var changes = new Changes({
url: 'http://user:pass@127.0.0.1:5984/database',
timeout: {
max: 60000,
step: 5000
}
});

//
// Dump changes as they come in.
//
changes.on('change', function (doc) {
console.dir(doc);
});

//
// The callback will be called once a _changes
// connection has been established or with an
// error if the first connection fails.
//
changes.listen(function (err) {
if (err) {
console.log('Did not connect to _changes on first attempt');
console.dir(err);
changes.retry.enabled = false;
return process.exit(1);
}

console.log('Listening for _changes');
});
`

Pre-fetching Views

Often when you establish a connection to _changes you also want to know about the other documents in a view before the current update_seq. This is supported like this:

` js
var Changes = require('changes');

var changes = new Changes({
url: 'http://user:pass@127.0.0.1:5984/database',
views: {
'important': {
path: '_design/Some/_view/name',
query: { include_docs: true }
}
},
timeout: {
max: 60000,
step: 5000
}
});

//
// All rows from a queries view will be emitted
// in the views: event before the
// _changes listener starts.
//
changes.on('views:important', function (rows) {
//
// Dump any existing "important" rows.
//
console.dir(rows);
});

//
// Dump changes as they come in.
//
changes.on('change', function (doc) {
console.dir(doc);
});

//
// The callback will be called once a _changes
// connection has been established or with an
// error if the first connection fails.
//
changes.listen(function (err) {
if (err) {
console.log('Did not connect to _changes on first attempt');
console.dir(err);
changes.retry.enabled = false;
return process.exit(1);
}

console.log('Listening for _changes');
});
``

#### License: MIT
#### Authors: Bradley Meck, Maciej Malecki, Charlie Robbins