content/xbl/src/nsXBLProtoImplField.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 Communicator client code.
  16  *
  17  * The Initial Developer of the Original Code is
  18  * Netscape Communications Corporation.
  19  * Portions created by the Initial Developer are Copyright (C) 1998
  20  * the Initial Developer. All Rights Reserved.
  21  *
  22  * Contributor(s):
  23  *   David Hyatt <hyatt@netscape.com> (Original Author)
  24  *
  25  * Alternatively, the contents of this file may be used under the terms of
  26  * either of the GNU General Public License Version 2 or later (the "GPL"),
  27  * or 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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  36  *
  37  * ***** END LICENSE BLOCK ***** */
  38
  39 #include "nsIAtom.h"
  40 #include "nsString.h"
  41 #include "jsapi.h"
  42 #include "nsIContent.h"
  43 #include "nsString.h"
  44 #include "nsUnicharUtils.h"
  45 #include "nsReadableUtils.h"
  46 #include "nsXBLProtoImplField.h"
  47 #include "nsIScriptContext.h"
  48 #include "nsContentUtils.h"
  49 #include "nsIURI.h"
  50
  51 nsXBLProtoImplField::nsXBLProtoImplField(const PRUnichar* aName, const PRUnichar* aReadOnly)
  52   : mNext(nsnull),
  53     mFieldText(nsnull),
  54     mFieldTextLength(0),
  55     mLineNumber(0)
  56 {
  57   MOZ_COUNT_CTOR(nsXBLProtoImplField);
  58   mName = NS_strdup(aName);  // XXXbz make more sense to use a stringbuffer?
  59
  60   mJSAttributes = JSPROP_ENUMERATE;
  61   if (aReadOnly) {
  62     nsAutoString readOnly; readOnly.Assign(*aReadOnly);
  63     if (readOnly.LowerCaseEqualsLiteral("true"))
  64       mJSAttributes |= JSPROP_READONLY;
  65   }
  66 }
  67
  68 nsXBLProtoImplField::~nsXBLProtoImplField()
  69 {
  70   MOZ_COUNT_DTOR(nsXBLProtoImplField);
  71   if (mFieldText)
  72     nsMemory::Free(mFieldText);
  73   NS_Free(mName);
  74   delete mNext;
  75 }
  76
  77 void
  78 nsXBLProtoImplField::AppendFieldText(const nsAString& aText)
  79 {
  80   if (mFieldText) {
  81     nsDependentString fieldTextStr(mFieldText, mFieldTextLength);
  82     nsAutoString newFieldText = fieldTextStr + aText;
  83     PRUnichar* temp = mFieldText;
  84     mFieldText = ToNewUnicode(newFieldText);
  85     mFieldTextLength = newFieldText.Length();
  86     nsMemory::Free(temp);
  87   }
  88   else {
  89     mFieldText = ToNewUnicode(aText);
  90     mFieldTextLength = aText.Length();
  91   }
  92 }
  93
  94 nsresult
  95 nsXBLProtoImplField::InstallField(nsIScriptContext* aContext,
  96                                   JSObject* aBoundNode,
  97                                   nsIPrincipal* aPrincipal,
  98                                   nsIURI* aBindingDocURI,
  99                                   PRBool* aDidInstall) const
 100 {
 101   NS_PRECONDITION(aBoundNode,
 102                   "uh-oh, bound node should NOT be null or bad things will "
 103                   "happen");
 104
 105   *aDidInstall = PR_FALSE;
 106
 107   if (mFieldTextLength == 0) {
 108     return NS_OK;
 109   }
 110
 111   jsval result = JSVAL_NULL;
 112
 113   // EvaluateStringWithValue and JS_DefineUCProperty can both trigger GC, so
 114   // protect |result| here.
 115   nsresult rv;
 116   nsAutoGCRoot root(&result, &rv);
 117   if (NS_FAILED(rv))
 118     return rv;
 119
 120   nsCAutoString uriSpec;
 121   aBindingDocURI->GetSpec(uriSpec);
 122
 123   JSContext* cx = (JSContext*) aContext->GetNativeContext();
 124   NS_ASSERTION(!::JS_IsExceptionPending(cx),
 125                "Shouldn't get here when an exception is pending!");
 126
 127   // compile the literal string
 128   PRBool undefined;
 129   nsCOMPtr<nsIScriptContext> context = aContext;
 130   rv = context->EvaluateStringWithValue(nsDependentString(mFieldText,
 131                                                           mFieldTextLength),
 132                                         aBoundNode,
 133                                         aPrincipal, uriSpec.get(),
 134                                         mLineNumber, JSVERSION_LATEST,
 135                                         (void*) &result, &undefined);
 136   if (NS_FAILED(rv))
 137     return rv;
 138
 139   // If EvaluateStringWithValue() threw an exception, just report it now.
 140   // Failure to evaluate a field should stop neither the get of the field value
 141   // nor an enumeration attempt.
 142   if (::JS_IsExceptionPending(cx)) {
 143     ::JS_ReportPendingException(cx);
 144   }
 145
 146   if (undefined) {
 147     result = JSVAL_VOID;
 148   }
 149
 150   // Define the evaluated result as a JS property
 151   nsDependentString name(mName);
 152   JSAutoRequest ar(cx);
 153   if (!::JS_DefineUCProperty(cx, aBoundNode,
 154                              reinterpret_cast<const jschar*>(mName),
 155                              name.Length(), result, nsnull, nsnull,
 156                              mJSAttributes)) {
 157     return NS_ERROR_OUT_OF_MEMORY;
 158   }
 159
 160   *aDidInstall = PR_TRUE;
 161   return NS_OK;
 162 }