webkit/port/bindings/v8/JSXPathNSResolver.cpp

// Copyright (c) 2008, Google Inc.
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//
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// modification, are permitted provided that the following conditions are
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// notice, this list of conditions and the following disclaimer.
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#include "config.h"
#include "JSXPathNSResolver.h"

#if ENABLE(XPATH)

#include "v8_proxy.h"
#include "v8_binding.h"
#include "PlatformString.h"

namespace WebCore {

JSXPathNSResolver::JSXPathNSResolver(v8::Handle<v8::Object> resolver)
: m_resolver(resolver) {
}

JSXPathNSResolver::~JSXPathNSResolver() {
}

String JSXPathNSResolver::lookupNamespaceURI(const String& prefix) {
  v8::Handle<v8::Function> lookupNamespaceURIFunc;
  v8::Handle<v8::String> lookupNamespaceURIName = v8::String::New("lookupNamespaceURI");

  // Check if the resolver has a function property named lookupNamespaceURI.
  if (m_resolver->Has(lookupNamespaceURIName)) {
    v8::Handle<v8::Value> lookupNamespaceURI = m_resolver->Get(lookupNamespaceURIName);
    if (lookupNamespaceURI->IsFunction()) {
      lookupNamespaceURIFunc = v8::Handle<v8::Function>::Cast(lookupNamespaceURI);
    }
  }

  if (lookupNamespaceURIFunc.IsEmpty() && !m_resolver->IsFunction()) {
    Frame* frame = V8Proxy::retrieveFrameForEnteredContext();
    log_info(frame, "XPathNSResolver does not have a lookupNamespaceURI method.", String());
    return String();
  }

  // Catch exceptions from calling the namespace resolver.
  v8::TryCatch try_catch;
  try_catch.SetVerbose(true);  // Print exceptions to console.

  const int argc = 1;
  v8::Handle<v8::Value> argv[argc] = { v8String(prefix) };
  v8::Handle<v8::Function> function = lookupNamespaceURIFunc.IsEmpty()
      ? v8::Handle<v8::Function>::Cast(m_resolver)
      : lookupNamespaceURIFunc;

  V8Proxy* proxy = V8Proxy::retrieve();
  v8::Handle<v8::Value> retval = proxy->CallFunction(function, m_resolver, argc, argv);

  // Eat exceptions from namespace resolver and return an empty string. This
  // will most likely cause NAMESPACE_ERR.
  if (try_catch.HasCaught()) {
    return String();
  }

  return valueToStringWithNullCheck(retval);
}

}

#endif // ENABLE(XPATH)