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

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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: http://forums.enyojs.com/discussion/1830/how-to-merge-records-from-different-collections.
enyo.kind({
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 = this.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...
record.setObject(data);
}
}
// 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
this.merge(records);
}
}
});
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