extensions/xforms/nsXFormsValueElement.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* ***** BEGIN LICENSE BLOCK *****
   3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   4  *
   5  * The contents of this file are subject to the Mozilla Public License Version
   6  * 1.1 (the "License"); you may not use this file except in compliance with
   7  * the License. You may obtain a copy of the License at
   8  * http://www.mozilla.org/MPL/
   9  *
  10  * Software distributed under the License is distributed on an "AS IS" basis,
  11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  12  * for the specific language governing rights and limitations under the
  13  * License.
  14  *
  15  * The Original Code is Mozilla XForms support.
  16  *
  17  * The Initial Developer of the Original Code is
  18  * IBM Corporation.
  19  * Portions created by the Initial Developer are Copyright (C) 2004
  20  * the Initial Developer. All Rights Reserved.
  21  *
  22  * Contributor(s):
  23  *  Brian Ryner <bryner@brianryner.com>
  24  *
  25  * Alternatively, the contents of this file may be used under the terms of
  26  * either the GNU General Public License Version 2 or later (the "GPL"), or
  27  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  28  * in which case the provisions of the GPL or the LGPL are applicable instead
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  33  * and other provisions required by the GPL or the LGPL. If you do not delete
  34  * the provisions above, a recipient may use your version of this file under
  35  * the terms of any one of the MPL, the GPL or the LGPL.
  36  *
  37  * ***** END LICENSE BLOCK ***** */
  38
  39 #include "nsIXFormsValueElement.h"
  40 #include "nsXFormsStubElement.h"
  41 #include "nsIXTFElementWrapper.h"
  42 #include "nsIDOM3Node.h"
  43 #include "nsXFormsUtils.h"
  44 #include "nsIDOMElement.h"
  45 #include "nsStringAPI.h"
  46
  47 /**
  48  * Implementation of the XForms \<value\> element.
  49  *
  50  * @note The value element does not display any content, it simply provides
  51  * a value from inline text or instance data.
  52  */
  53
  54 class nsXFormsValueElement : public nsXFormsStubElement,
  55                              public nsIXFormsValueElement
  56 {
  57 public:
  58   nsXFormsValueElement() : mElement(nsnull) {}
  59
  60   NS_DECL_ISUPPORTS_INHERITED
  61
  62   // nsIXTFElement overrides
  63   NS_IMETHOD OnCreated(nsIXTFElementWrapper *aWrapper);
  64
  65   // nsIXFormsValueElement
  66   NS_DECL_NSIXFORMSVALUEELEMENT
  67
  68 private:
  69   nsIDOMElement *mElement;
  70 };
  71
  72 NS_IMPL_ISUPPORTS_INHERITED1(nsXFormsValueElement,
  73                              nsXFormsStubElement,
  74                              nsIXFormsValueElement)
  75
  76 NS_IMETHODIMP
  77 nsXFormsValueElement::OnCreated(nsIXTFElementWrapper *aWrapper)
  78 {
  79   nsCOMPtr<nsIDOMElement> node;
  80   aWrapper->GetElementNode(getter_AddRefs(node));
  81
  82   // It's ok to keep pointer to mElement.  mElement will have an
  83   // owning reference to this object, so as long as we null out mElement in
  84   // OnDestroyed, it will always be valid.
  85
  86   mElement = node;
  87   NS_ASSERTION(mElement, "Wrapper is not an nsIDOMElement, we'll crash soon");
  88
  89   return NS_OK;
  90 }
  91
  92 // nsIXFormsValueElement
  93
  94 NS_IMETHODIMP
  95 nsXFormsValueElement::GetValue(nsAString &aValue)
  96 {
  97   nsString value;
  98   PRBool singleNodeVal =
  99     nsXFormsUtils::GetSingleNodeBindingValue(mElement, value);
 100   if (singleNodeVal) {
 101     aValue.Assign(value);
 102     return NS_OK;
 103   }
 104
 105   nsCOMPtr<nsIDOM3Node> node3 = do_QueryInterface(mElement);
 106   NS_ASSERTION(node3, "dom elements must support dom3");
 107
 108   return node3->GetTextContent(aValue);
 109 }
 110
 111 NS_HIDDEN_(nsresult)
 112 NS_NewXFormsValueElement(nsIXTFElement **aResult)
 113 {
 114   *aResult = new nsXFormsValueElement();
 115   if (!*aResult)
 116     return NS_ERROR_OUT_OF_MEMORY;
 117
 118   NS_ADDREF(*aResult);
 119   return NS_OK;
 120 }