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@clinuz clinuz/SampleCollection.js Secret
Last active Dec 28, 2015

What would you like to do?
Example of custom merge strategy for integrating fetched data into an enyo.Collection that may have records that already exist in the shared store (with another enyo.Collection) as per the discussion:
name: "sample.Collection",
kind: "enyo.Collection",
// this may not be preferred but for example we overload fetch to always default
// to the new _reuseOrAdd_ strategy unless specified
fetch: function (opts) {
opts = opts || {};
opts.strategy = opts.strategy || "reuseOrAdd";
// ensure we're passing our new arguments
this.inherited(arguments, [opts]);
// we use a custom merge strategy to check if the record exists in the store
// and reuse it if it does
reuseOrAdd: function (records) {
// we need to be able to figure out what the primary key is that will be
// used to check uniqueness in the store, since you may already know this
// you could hardcode it in
var store =,
proto = this.model.prototype,
pk = proto.primaryKey;
// we still have to check to make sure this is in an array form
// so it is usable directly with a single record as well
if (records) {
records = enyo.isArray(records)? records: [records];
for (var i=0, data, record; (data=records[i]); ++i) {
// we use the _findLocal_ method of the store to see if a record
// with these keys already exists
record = store.findLocal(this.model, data);
if (record) {
// if it does we replace the entry with the existing one
records[i] = record;
// optionally you could update the value if that was something you wanted
// to do as well such as...
// now that we know we either have new records or existing records
// and we want to be able to safely call this whether adding or merging
// with existing data we let the default merge now do its thing
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