Initial commit

lib/assets/javascripts/builder/value-objects/analysis-node-ids.js

@@ -0,0 +1,66 @@
+var _ = require('underscore');
+
+var SOURCE_ID_REGEX = /^([a-z]+)(\d*)$/; // matches a string with one or more letters + numbers, e.g. 'b2'
+
+var newId = function (id, seqChange) {
+  if (!id || !id.match) throw new Error('invalid id');
+
+  var matches = id.match(SOURCE_ID_REGEX);
+  matches[2] = matches[2] || -1;
+
+  if (matches && matches.length === 3) {
+    // letter + next number
+    var letter = matches[1];
+    var seq = parseInt(matches[2], 10) + seqChange;
+    return letter + Math.max(seq, 0);
+  } else {
+    throw new Error('invalid id');
+  }
+};
+
+/**
+ * Encapsulates logic related to the nodes' IDs.
+ */
+module.exports = {
+
+  /**
+   * Get next id in sequence of given source id.
+   * @param {String} id, e.g. 'c2'
+   * @return {String} e.g. 'c3'
+   */
+  next: function (id) {
+    return newId(id, 1);
+  },
+
+  prev: function (id) {
+    return newId(id, -1);
+  },
+
+  /**
+   * Get the letter representation.
+   * @param {String, Object} sourceId or backbone model that have id. e.g. 'c2'
+   * @return {String} e.g. 'c' or an empty string if there is no letter in the given id
+   */
+  letter: function (sourceId) {
+    if (!sourceId || !_.isString(sourceId)) return '';
+    var match = sourceId.match(/^([a-z]+)/);
+    return _.isArray(match) && match[0] || '';
+  },
+
+  /**
+   * Get the sequence representation.
+   * @param {String, Object} sourceId or backbone model that have id. e.g. 'c2'
+   * @return {Number} e.g. 2 or undefined if there is no sequence
+   */
+  sequence: function (sourceId) {
+    if (!sourceId || !_.isString(sourceId)) return;
+    var match = sourceId.match(/(\d+$)/);
+    return _.isArray(match) && match[0] || undefined;
+  },
+
+  changeLetter: function (id, newLetter) {
+    var seq = id.match(/(\d+)$/)[0];
+    return newLetter + seq;
+  }
+
+};