gecko/content/xbl/src/nsXBLProtoImplField.cpp

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla Communicator client code.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   David Hyatt <hyatt@netscape.com> (Original Author)
 *
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 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
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#include "nsIAtom.h"
#include "nsString.h"
#include "jsapi.h"
#include "nsIContent.h"
#include "nsString.h"
#include "nsUnicharUtils.h"
#include "nsReadableUtils.h"
#include "nsXBLProtoImplField.h"
#include "nsIScriptContext.h"
#include "nsContentUtils.h"
#include "nsIURI.h"

nsXBLProtoImplField::nsXBLProtoImplField(const PRUnichar* aName, const PRUnichar* aReadOnly)
  : mNext(nsnull),
    mFieldText(nsnull),
    mFieldTextLength(0),
    mLineNumber(0)
{
  MOZ_COUNT_CTOR(nsXBLProtoImplField);
  mName = NS_strdup(aName);  // XXXbz make more sense to use a stringbuffer?
  
  mJSAttributes = JSPROP_ENUMERATE;
  if (aReadOnly) {
    nsAutoString readOnly; readOnly.Assign(*aReadOnly);
    if (readOnly.LowerCaseEqualsLiteral("true"))
      mJSAttributes |= JSPROP_READONLY;
  }
}

nsXBLProtoImplField::~nsXBLProtoImplField()
{
  MOZ_COUNT_DTOR(nsXBLProtoImplField);
  if (mFieldText)
    nsMemory::Free(mFieldText);
  NS_Free(mName);
  NS_CONTENT_DELETE_LIST_MEMBER(nsXBLProtoImplField, this, mNext);
}

void 
nsXBLProtoImplField::AppendFieldText(const nsAString& aText)
{
  if (mFieldText) {
    nsDependentString fieldTextStr(mFieldText, mFieldTextLength);
    nsAutoString newFieldText = fieldTextStr + aText;
    PRUnichar* temp = mFieldText;
    mFieldText = ToNewUnicode(newFieldText);
    mFieldTextLength = newFieldText.Length();
    nsMemory::Free(temp);
  }
  else {
    mFieldText = ToNewUnicode(aText);
    mFieldTextLength = aText.Length();
  }
}

nsresult
nsXBLProtoImplField::InstallField(nsIScriptContext* aContext,
                                  JSObject* aBoundNode,
                                  nsIPrincipal* aPrincipal,
                                  nsIURI* aBindingDocURI,
                                  PRBool* aDidInstall) const
{
  NS_PRECONDITION(aBoundNode,
                  "uh-oh, bound node should NOT be null or bad things will "
                  "happen");

  *aDidInstall = PR_FALSE;

  if (mFieldTextLength == 0) {
    return NS_OK;
  }

  jsval result = JSVAL_NULL;
  
  // EvaluateStringWithValue and JS_DefineUCProperty can both trigger GC, so
  // protect |result| here.
  nsresult rv;
  nsAutoGCRoot root(&result, &rv);
  if (NS_FAILED(rv))
    return rv;

  nsCAutoString uriSpec;
  aBindingDocURI->GetSpec(uriSpec);
  
  JSContext* cx = (JSContext*) aContext->GetNativeContext();
  NS_ASSERTION(!::JS_IsExceptionPending(cx),
               "Shouldn't get here when an exception is pending!");
  
  // compile the literal string
  PRBool undefined;
  nsCOMPtr<nsIScriptContext> context = aContext;
  rv = context->EvaluateStringWithValue(nsDependentString(mFieldText,
                                                          mFieldTextLength), 
                                        aBoundNode,
                                        aPrincipal, uriSpec.get(),
                                        mLineNumber, JSVERSION_LATEST,
                                        (void*) &result, &undefined);
  if (NS_FAILED(rv))
    return rv;

  if (undefined) {
    result = JSVAL_VOID;
  }

  // Define the evaluated result as a JS property
  nsDependentString name(mName);
  JSAutoRequest ar(cx);
  if (!::JS_DefineUCProperty(cx, aBoundNode,
                             reinterpret_cast<const jschar*>(mName), 
                             name.Length(), result, nsnull, nsnull,
                             mJSAttributes)) {
    return NS_ERROR_OUT_OF_MEMORY;
  }

  *aDidInstall = PR_TRUE;
  return NS_OK;
}