Sir Transformalot

A utility for version transformation of data.

SETUP

You should have transforms folder with file *.js that represents transform for your entity Example of transforms file you can find here

Configure transform

// entity.js
module.exports = {
    v2: {
        V1toV2: {
            transform(data, preparedData) {
                return data;
            },
 
            // optional
            prepareTransform(id, mongo, callback) {
                mongo.findOne({id}, callback);
            }
        }
    }
}

or if you send in the options argument:

// entity.js
module.exports = {
    v2: {
        V1toV2: {
            transform(data, preparedData, options) {
                return data;
            },
 
            // optional
            prepareTransform(id, mongo, options, callback) {
                mongo.findOne({id}, callback);
            }
        }
    }
}

Transform for single object

The options argument is optional and allows you to send any additional data in to the transformation that you might need.

transforms.entity.transformObject(id, data, fromVersion, toVersion, mongo, options, callback)

Transform for list with streams

The options argument is optional.

var transformStream = transforms.entity.getTransformStream('v3', req.params.version, mongo, options);
pump(db.getDataStream(), transformStream, JSONStream.stringify(), res, function(err) {
    if(err) {
        return next(err);
    };
});