loopback/common/models/checkpoint.js

70 lines
1.7 KiB
JavaScript

/**
* Module Dependencies.
*/
var assert = require('assert');
/**
* Checkpoint list entry.
*
* @property id {Number} the sequencial identifier of a checkpoint
* @property time {Number} the time when the checkpoint was created
* @property sourceId {String} the source identifier
*
* @class Checkpoint
* @inherits {PersistedModel}
*/
module.exports = function(Checkpoint) {
// Workaround for https://github.com/strongloop/loopback/issues/292
Checkpoint.definition.rawProperties.time.default =
Checkpoint.definition.properties.time.default = function() {
return new Date();
};
/**
* Get the current checkpoint id
* @callback {Function} callback
* @param {Error} err
* @param {Number} checkpointId The current checkpoint id
*/
Checkpoint.current = function(cb) {
var Checkpoint = this;
this.find({
limit: 1,
order: 'seq DESC'
}, function(err, checkpoints) {
if (err) return cb(err);
var checkpoint = checkpoints[0];
if (checkpoint) {
cb(null, checkpoint.seq);
} else {
Checkpoint.create({ seq: 1 }, function(err, checkpoint) {
if (err) return cb(err);
cb(null, checkpoint.seq);
});
}
});
};
Checkpoint.observe('before save', function(ctx, next) {
if (!ctx.instance) {
// Example: Checkpoint.updateAll() and Checkpoint.updateOrCreate()
return next(new Error('Checkpoint does not support partial updates.'));
}
var model = ctx.instance;
if (!model.getId() && model.seq === undefined) {
model.constructor.current(function(err, seq) {
if (err) return next(err);
model.seq = seq + 1;
next();
});
} else {
next();
}
});
};