nsParserUtils.cpp

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#include "nsParserUtils.h"
#include "nsIParser.h" // for kQuote et. al.
#include "jsapi.h"
#include "nsReadableUtils.h"
#include "nsCRT.h"

#define SKIP_WHITESPACE(iter, end_iter)                          \
  while ((iter) != (end_iter) && nsCRT::IsAsciiSpace(*(iter))) { \
    ++(iter);                                                    \
  }                                                              \
  if ((iter) == (end_iter))                                      \
    break

#define SKIP_ATTR_NAME(iter, end_iter)                            \
  while ((iter) != (end_iter) && !nsCRT::IsAsciiSpace(*(iter)) && \
         *(iter) != '=') {                                        \
    ++(iter);                                                     \
  }                                                               \
  if ((iter) == (end_iter))                                       \
    break

PRBool
nsParserUtils::GetQuotedAttributeValue(const nsAString& aSource,
                                       const nsAString& aAttribute,
                                       nsAString& aValue)
{
  NS_ASSERTION(!aAttribute.IsEmpty(), "Empty attribute name cannot be searched for usefully");
  aValue.Truncate();
  nsAString::const_iterator start, end;
  aSource.BeginReading(start);
  aSource.EndReading(end);
  nsAString::const_iterator iter;
  
  while (start != end) {
    SKIP_WHITESPACE(start, end);
    iter = start;
    SKIP_ATTR_NAME(iter, end);

    // Remember the attr name.
    const nsAString & attrName = Substring(start, iter);

    // Now check whether this is a valid name="value" pair.
    start = iter;
    SKIP_WHITESPACE(start, end);
    if (*start != '=') {
      // No '=', so this is not a name="value" pair.  We don't know
      // what it is, and we have no way to handle it.
      break;
    }
    
    // Have to skip the value.
    ++start;
    SKIP_WHITESPACE(start, end);
    PRUnichar q = *start;
    if (q != kQuote && q != kApostrophe) {
      // Not a valid quoted value, so bail.
      break;
    }
    
    ++start;  // Point to the first char of the value.
    iter = start;
    if (!FindCharInReadable(q, iter, end)) {
      // Oops, unterminated quoted string.
      break;
    }
    
    // At this point attrName holds the name of the "attribute" and
    // the value is between start and iter.
    
    if (!attrName.Equals(aAttribute)) {
      // Resume scanning after the end of the attribute value.
      start = iter;
      ++start;  // To move past the quote char.
      continue;
    }

    aValue = Substring(start, iter);
    return PR_TRUE;
  }

  return PR_FALSE;
}


// XXX Stolen from nsHTMLContentSink. Needs to be shared.
// XXXbe share also with nsRDFParserUtils.cpp and nsHTMLContentSink.cpp
// Returns PR_TRUE if the language name is a version of JavaScript and
// PR_FALSE otherwise
PRBool
nsParserUtils::IsJavaScriptLanguage(const nsString& aName, const char* *aVersion)
{
  JSVersion version = JSVERSION_UNKNOWN;

  if (aName.LowerCaseEqualsLiteral("javascript") ||
      aName.LowerCaseEqualsLiteral("livescript") ||
      aName.LowerCaseEqualsLiteral("mocha")) {
    version = JSVERSION_DEFAULT;
  }
  else if (aName.LowerCaseEqualsLiteral("javascript1.0")) {
    version = JSVERSION_1_0;
  }
  else if (aName.LowerCaseEqualsLiteral("javascript1.1")) {
    version = JSVERSION_1_1;
  }
  else if (aName.LowerCaseEqualsLiteral("javascript1.2")) {
    version = JSVERSION_1_2;
  }
  else if (aName.LowerCaseEqualsLiteral("javascript1.3")) {
    version = JSVERSION_1_3;
  }
  else if (aName.LowerCaseEqualsLiteral("javascript1.4")) {
    version = JSVERSION_1_4;
  }
  else if (aName.LowerCaseEqualsLiteral("javascript1.5")) {
    version = JSVERSION_1_5;
  }
  else if (aName.LowerCaseEqualsLiteral("javascript1.6")) {
    version = JSVERSION_1_6;
  }
  if (version == JSVERSION_UNKNOWN)
    return PR_FALSE;
  *aVersion = JS_VersionToString(version);
  return PR_TRUE;
}

void
nsParserUtils::SplitMimeType(const nsAString& aValue, nsString& aType,
                             nsString& aParams)
{
  aType.Truncate();
  aParams.Truncate();
  PRInt32 semiIndex = aValue.FindChar(PRUnichar(';'));
  if (-1 != semiIndex) {
    aType = Substring(aValue, 0, semiIndex);
    aParams = Substring(aValue, semiIndex + 1,
                       aValue.Length() - (semiIndex + 1));
    aParams.StripWhitespace();
  }
  else {
    aType = aValue;
  }
  aType.StripWhitespace();
}