/// <summary>
/// Handles META tags that set page encoding
/// </summary>
/// <param name="p">HTML parser object that is used for parsing</param>
/// <param name="chunk">Parsed chunk that should contain tag META</param>
/// <param name="encodingSet">Your own flag that shows whether encoding was already set or not, if set
/// once then it should not be changed - this is the logic applied by major browsers</param>
/// <returns>True if this was META tag setting Encoding, false otherwise</returns>
public static bool HandleMetaEncoding(HTMLparser p, HTMLchunk chunk, ref bool encodingSet)
{
if (chunk.Tag.Length != 4 || chunk.Tag[0] != 'm' || chunk.Tag != "meta")
{
return(false);
}
// if we do not use hashmode already then we call conversion explicitly
// this is slow, but METAs are very rare so performance penalty is low
if (!chunk.HashMode)
{
chunk.ConvertParamsToHash();
}
var key = chunk.Params["http-equiv"] as string;
if (key != null)
{
// FIXIT: even though this is happening rare I really don't like lower casing stuff
// that most likely would not need to be - if you feel bored then rewrite this bit
// to make it faster, it is really easy...
switch (key.ToLower())
{
case "content-type":
// rare case (appears to work in IE) reported to exist in some pages by Martin B�chtold
case "content-category":
// we might have charset here that may hint at necessity to decode page
// check for possible encoding change
// once encoding is set it should not be changed, but you can be damn
// sure there are web pages out there that do that!!!
if (!encodingSet)
{
var data = chunk.Params["content"] as string;
// it is possible we have broken META tag without Content part
if (data != null)
{
if (p.SetEncoding(data))
{
// we may need to re-encode title
if (!encodingSet)
{
// here you need to reencode any text that you found so far
// most likely it will be just TITLE, the rest can be ignored anyway
encodingSet = true;
}
}
else
{
// failed to set encoding - most likely encoding string
// was incorrect or your machine lacks codepages or something
// else - might be good idea to put warning message here
}
}
}
return(true);
default: break;
}
}
return(false);
}
/// <summary>
/// Inits tag parser
/// </summary>
/// <param name="chunk"></param>
/// <param name="text"></param>
internal void Init(HTMLparser p, HTMLchunk chunk, DynaString text, byte[] html, int dataLength, HTMLentities e, HTMLheuristics he)
{
_p = p;
_chunk = chunk;
_text = text;
_html = html;
_dataLength = dataLength;
// we don't want to be too close to end of data when dealing with heuristics
_maxHeuDataLength = _dataLength - MIN_DATA_SIZE_FOR_HEURISTICS;
_e = e;
_he = he;
}
