extensions/xforms/nsXFormsOutputElement.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  * Novell, Inc.
  19  * Portions created by the Initial Developer are Copyright (C) 2004
  20  * the Initial Developer. All Rights Reserved.
  21  *
  22  * Contributor(s):
  23  *  Allan Beaufour <abeaufour@novell.com>
  24  *  Olli Pettay <Olli.Pettay@helsinki.fi>
  25  *
  26  * Alternatively, the contents of this file may be used under the terms of
  27  * either the GNU General Public License Version 2 or later (the "GPL"), or
  28  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  29  * in which case the provisions of the GPL or the LGPL are applicable instead
  30  * of those above. If you wish to allow use of your version of this file only
  31  * under the terms of either the GPL or the LGPL, and not to allow others to
  32  * use your version of this file under the terms of the MPL, indicate your
  33  * decision by deleting the provisions above and replace them with the notice
  34  * and other provisions required by the GPL or the LGPL. If you do not delete
  35  * the provisions above, a recipient may use your version of this file under
  36  * the terms of any one of the MPL, the GPL or the LGPL.
  37  *
  38  * ***** END LICENSE BLOCK ***** */
  39
  40 #ifdef DEBUG
  41 //#define DEBUG_XF_OUTPUT
  42 #endif
  43
  44 #include "nsAutoPtr.h"
  45 #include "nsCOMPtr.h"
  46 #include "nsMemory.h"
  47 #include "nsStringAPI.h"
  48 #include "nsIDOM3Node.h"
  49 #include "nsIDOMDocument.h"
  50 #include "nsIDOMElement.h"
  51 #include "nsIDOMEventTarget.h"
  52 #include "nsIDOMXPathExpression.h"
  53 #include "nsIDOMXPathResult.h"
  54 #include "nsISchema.h"
  55
  56 #include "nsIModelElementPrivate.h"
  57 #include "nsXFormsDelegateStub.h"
  58 #include "nsXFormsAtoms.h"
  59 #include "nsXFormsUtils.h"
  60 #include "nsIXFormsUIWidget.h"
  61 #include "nsXFormsModelElement.h"
  62
  63
  64 /**
  65  * Implementation of the XForms \<output\> element.
  66  *
  67  * \<output\> is not really that different from \<input\>
  68  * (ie. nsXFormsDelegateStub), except that it has an "value" attribute that
  69  * must be handled separately because it is evaluated to a string result.
  70  *
  71  * @see http://www.w3.org/TR/xforms/slice8.html#ui-output
  72  */
  73 class nsXFormsOutputElement : public nsXFormsDelegateStub
  74 {
  75 public:
  76   // nsIXFormsControl
  77   NS_IMETHOD Bind(PRBool* aContextChanged);
  78   NS_IMETHOD Refresh();
  79   NS_IMETHOD GetBoundNode(nsIDOMNode **aBoundNode);
  80
  81   // nsIXFormsDelegate
  82   NS_IMETHOD GetValue(nsAString& aValue);
  83   NS_IMETHOD SetValue(const nsAString& aValue);
  84   NS_IMETHOD GetHasBoundNode(PRBool *aHasBoundNode);
  85
  86   virtual PRBool IsContentAllowed();
  87
  88   nsXFormsOutputElement();
  89
  90 private:
  91   // The value of the "value" attribute (if any). Updated by Bind()
  92   nsString       mValue;
  93
  94   // Use the "value" attribute
  95   PRBool         mUseValueAttribute;
  96 };
  97
  98 nsXFormsOutputElement::nsXFormsOutputElement()
  99   : nsXFormsDelegateStub(NS_LITERAL_STRING("output")),
 100     mUseValueAttribute(PR_FALSE)
 101 {
 102 }
 103
 104 // nsIXFormsControl
 105
 106 nsresult
 107 nsXFormsOutputElement::Bind(PRBool *aContextChanged)
 108 {
 109   mValue.SetIsVoid(PR_TRUE);
 110   mUseValueAttribute = PR_FALSE;
 111
 112   nsresult rv = nsXFormsDelegateStub::Bind(aContextChanged);
 113   NS_ENSURE_SUCCESS(rv, rv);
 114
 115   if (!mHasParent || !mElement || rv == NS_OK_XFORMS_DEFERRED)
 116     return NS_OK;
 117
 118   // Besides the standard single node binding (SNB) attributes, \<output\>
 119   // also has a "value" attribute, which is used when there are not other SNB
 120   // attributes.
 121   if (!HasBindingAttribute()) {
 122     mUseValueAttribute = PR_TRUE;
 123   } else {
 124     PRBool hasAttr;
 125     rv = mElement->HasAttribute(NS_LITERAL_STRING("ref"), &hasAttr);
 126     NS_ENSURE_SUCCESS(rv, rv);
 127     if (!hasAttr) {
 128       rv = mElement->HasAttribute(NS_LITERAL_STRING("bind"), &hasAttr);
 129       NS_ENSURE_SUCCESS(rv, rv);
 130       mUseValueAttribute = !hasAttr;
 131     }
 132   }
 133
 134   if (!mUseValueAttribute)
 135     return NS_OK;
 136
 137   // Bind to model and set mBoundNode . The bound node is used for setting
 138   // context for our children (our parent's context in the case of @value),
 139   // and the call to ProcessNodeBinding() will not set it.
 140   rv = BindToModel(PR_TRUE);
 141   NS_ENSURE_SUCCESS(rv, rv);
 142
 143   // Process node binding
 144   nsCOMPtr<nsIDOMXPathResult> result;
 145   rv = ProcessNodeBinding(NS_LITERAL_STRING("value"),
 146                           nsIDOMXPathResult::STRING_TYPE,
 147                           getter_AddRefs(result));
 148   NS_ENSURE_SUCCESS(rv, rv);
 149
 150   if (rv == NS_OK_XFORMS_DEFERRED) {
 151     // Can't leave the output in the model list.  Since the xforms processor
 152     // is still deferring binds any contextcontrol helping to set the context
 153     // for the output's value expression probably isn't in the control list
 154     // yet.  And if that's the case, we can't have the output in the list
 155     // before the contextcontrol or the output won't bind right once the
 156     // deferred binds finallyhappen.  If we got mBoundNode in addition to
 157     // mModel during BindToModel, it isn't likely good, either, so junk it, too.
 158     mBoundNode = nsnull;
 159     if (mModel) {
 160       mModel->RemoveFormControl(this);
 161       mModel = nsnull;
 162     }
 163
 164     return NS_OK;
 165   }
 166
 167   if (result) {
 168     rv = result->GetStringValue(mValue);
 169     NS_ENSURE_SUCCESS(rv, rv);
 170   }
 171
 172   return NS_OK;
 173 }
 174
 175 NS_IMETHODIMP
 176 nsXFormsOutputElement::Refresh()
 177 {
 178   return nsXFormsDelegateStub::Refresh();
 179 }
 180
 181 NS_IMETHODIMP
 182 nsXFormsOutputElement::GetBoundNode(nsIDOMNode **aBoundNode)
 183 {
 184   return !mUseValueAttribute ? nsXFormsDelegateStub::GetBoundNode(aBoundNode)
 185                              : NS_OK;
 186 }
 187
 188 NS_IMETHODIMP
 189 nsXFormsOutputElement::GetHasBoundNode(PRBool *aHasBoundNode)
 190 {
 191   NS_ENSURE_ARG_POINTER(aHasBoundNode);
 192   *aHasBoundNode = (mBoundNode && !mUseValueAttribute) ? PR_TRUE : PR_FALSE;
 193   return NS_OK;
 194 }
 195
 196 NS_IMETHODIMP
 197 nsXFormsOutputElement::GetValue(nsAString& aValue)
 198 {
 199   if (mUseValueAttribute) {
 200     aValue = mValue;
 201     return NS_OK;
 202   }
 203
 204   return nsXFormsDelegateStub::GetValue(aValue);
 205 }
 206
 207 NS_IMETHODIMP
 208 nsXFormsOutputElement::SetValue(const nsAString& aValue)
 209 {
 210   // Setting the value on an output controls seems wrong semantically.
 211   return NS_ERROR_NOT_AVAILABLE;
 212 }
 213
 214 PRBool
 215 nsXFormsOutputElement::IsContentAllowed()
 216 {
 217   PRBool isAllowed = PR_TRUE;
 218
 219   // Output may not be bound to complexContent.
 220   PRBool isComplex = IsContentComplex();
 221   if (isComplex) {
 222     isAllowed = PR_FALSE;
 223   }
 224   return isAllowed;
 225 }
 226
 227 NS_HIDDEN_(nsresult)
 228 NS_NewXFormsOutputElement(nsIXTFElement **aResult)
 229 {
 230   *aResult = new nsXFormsOutputElement();
 231   if (!*aResult)
 232     return NS_ERROR_OUT_OF_MEMORY;
 233
 234   NS_ADDREF(*aResult);
 235   return NS_OK;
 236 }