knation · November 6, 2015 19:00 · Nov 6, 2015
diff --git a/salesforceId.js b/salesforceId.js
@@ -0,0 +1,61 @@
+/**
+ * The regex for a SF ID.
+ * @type {RegExp}
+ * @const
+ */
+var ID_REGEX = /^[0-9a-zA-Z]{15}([0-9a-zA-Z]{3})?$/;
+
+/**
+ * Array used to expand a SF ID from 15 to 18 characters.
+ * @type {Array.<String>}
+ * @const
+ */
+var ID_EXPAND_ARRAY = ['A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z','0','1','2','3','4','5'];
+
+/** 
+ * Constructor for SalesforceId object.
+ * @param {String} id
+ * @this {SalesforceId}
+ */
+function SalesforceId(id) {
+  this.id = id;
+}
+
+/**
+ * Checks the ID to make sure its format is valid for Salesforce.
+ * @this {SalesforceId}
+ * @return {Boolean}
+ */
+SalesforceId.prototype.isValid = function() {
+  return ID_REGEX.test(this.id);
+};
+
+/**
+ * Creates an 18-character ID if not already. If invalid, returns null.
+ * @this {SalesforceId}
+ * @return {?String}
+ */
+SalesforceId.prototype.expand = function() {
+  if (!this.isValid(this.id)) {
+    // Return null if invalid
+    return null;
+
+  } else if (this.id.length === 18) {
+    // Return as-is if already 18 chars
+    return this.id;
+
+  } else {
+    var chunks = [this.id.substr(0, 5), this.id.substr(5, 5), this.id.substr(10, 5)]
+        , chunkBits = ['','',''];
+
+    for (var i=0;i<chunks[0].length;i++) chunkBits[0] = (/[A-Z]/.test(chunks[0].substr(i, 1)) ? '1' : '0') + chunkBits[0];
+    for (var i=0;i<chunks[1].length;i++) chunkBits[1] = (/[A-Z]/.test(chunks[1].substr(i, 1)) ? '1' : '0') + chunkBits[1];
+    for (var i=0;i<chunks[2].length;i++) chunkBits[2] = (/[A-Z]/.test(chunks[2].substr(i, 1)) ? '1' : '0') + chunkBits[2];
+
+    chunkBits[0] = parseInt(chunkBits[0], 2);
+    chunkBits[1] = parseInt(chunkBits[1], 2);
+    chunkBits[2] = parseInt(chunkBits[2], 2);
+
+    return this.id + ID_EXPAND_ARRAY[chunkBits[0]] + ID_EXPAND_ARRAY[chunkBits[1]] + ID_EXPAND_ARRAY[chunkBits[2]];
+  }
+};