gistfile1.js

var recordsToAdd = [],
    numRecords = records.length;
function collectRecords(record) {
    if (recordsToAdd) {
        recordsToAdd.push(record);
    }
    --numRecords;
    if (numRecords === 0) {
        this.addLayers(recordsToAdd);
    }
}

var source = this.selectedSource;
var records = capGridPanel.getSelectionModel().getSelections();
for (var i=0, ii=records.length; i<ii; ++i) {
    source.createLayerRecord({
        name: records[i].get("name"),
        source: source.id
    }, collectRecords, this);
}