multinode-770213: Add NodeListType

lib/gcli/types/node.js

@@ -23,6 +23,7 @@ var types = require('gcli/types');
 var Type = require('gcli/types').Type;
 var Status = require('gcli/types').Status;
 var Conversion = require('gcli/types').Conversion;
+var BlankArgument = require('gcli/argument').BlankArgument;
 
 
 /**
@@ -45,11 +46,20 @@ if (typeof document !== 'undefined') {
   doc = document;
 }
 
+/**
+ * For testing only.
+ * The fake empty NodeList used when there are no matches, we replace this with
+ * something that looks better as soon as we have a document, so not only
+ * should you not use this, but you shouldn't cache it either.
+ */
+exports._empty = [];
+
 /**
  * Setter for the document that contains the nodes we're matching
  */
 exports.setDocument = function(document) {
   doc = document;
+  exports._empty = doc.querySelectorAll('x>:root');
 };
 
 /**
@@ -120,4 +130,64 @@ NodeType.prototype.parse = function(arg) {
 NodeType.prototype.name = 'node';
 
 
+
+/**
+ * A CSS expression that refers to a node list.
+ *
+ * The 'allowEmpty' option ensures that we do not complain if the entered CSS
+ * selector is valid, but does not match any nodes. There is some overlap
+ * between this option and 'defaultValue'. What the user wants, in most cases,
+ * would be to use 'defaultText' (i.e. what is typed rather than the value that
+ * it represents). However this isn't a concept that exists yet and should
+ * probably be a part of GCLI if/when it does.
+ * All NodeListTypes have an automatic defaultValue of an empty NodeList so
+ * they can easily be used in named parameters.
+ */
+function NodeListType(typeSpec) {
+  if ('allowEmpty' in typeSpec && typeof typeSpec.allowEmpty !== 'boolean') {
+    throw new Error('Legal values for allowEmpty are [true|false]');
+  }
+
+  this.allowEmpty = typeSpec.allowEmpty;
+}
+
+NodeListType.prototype = Object.create(Type.prototype);
+
+NodeListType.prototype.getBlank = function() {
+  return new Conversion(exports._empty, new BlankArgument(), Status.VALID);
+};
+
+NodeListType.prototype.stringify = function(value) {
+  if (value == null) {
+    return '';
+  }
+  return value.__gcliQuery || 'Error';
+};
+
+NodeListType.prototype.parse = function(arg) {
+  if (arg.text === '') {
+    return new Conversion(undefined, arg, Status.INCOMPLETE);
+  }
+
+  var nodes;
+  try {
+    nodes = doc.querySelectorAll(arg.text);
+  }
+  catch (ex) {
+    return new Conversion(undefined, arg, Status.ERROR,
+            l10n.lookup('nodeParseSyntax'));
+  }
+
+  if (nodes.length === 0 && !this.allowEmpty) {
+    return new Conversion(undefined, arg, Status.INCOMPLETE,
+        l10n.lookup('nodeParseNone'));
+  }
+
+  host.flashNodes(nodes, false);
+  return new Conversion(nodes, arg, Status.VALID, '');
+};
+
+NodeListType.prototype.name = 'nodelist';
+
+
 });