Initial commit

lib/assets/javascripts/dashboard/helpers/batch-process-items.js

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+const queue = require('queue-async');
+const _ = require('underscore');
+
+/**
+ * Convenient object to do async batch processing, and don't continue until all items have successfully finished.
+ * In case of error it will fail immediately.
+ *
+ * Example usage:
+ *   var batchProcess = require('../common/batch_process_items');
+ *   batchProcess({
+ *     items: [ ... ],
+ *     done: function () {
+ *       this.close();
+ *     },
+ *     fail: function (jqXHR, errorType, e) {
+ *       this._errorMsg = 'Server response: '+ jqXHR.responseText;
+ *       this.render();
+ *     }
+ *   });
+ *
+ * @param opts {Object}
+ *   howManyInParallel: {Number}
+ *   items: {Array} each item will be passed to processItem(item, ...
+ *   processItem: {Function} given an item and a callback, should call callback() for success case, or callback(error) if something failed.
+ *   fail: {Function}
+ *   done: {Function} called if all items
+ */
+module.exports = function (opts) {
+  var q = queue(opts.howManyInParallel);
+  _.each(opts.items, function (item) {
+    q.defer(function (callback) {
+      opts.processItem(item, callback);
+    });
+  });
+
+  q.awaitAll(function (error/*, result1, ..., resultN */) {
+    // error and results contains outcome of the jqXHR requests above, see http://api.jquery.com/jQuery.ajax/#jqXHR
+    if (error) {
+      opts.fail(error);
+    } else {
+      opts.done();
+    }
+  });
+};