parser/htmlparser/public/nsIHTMLContentSink.h

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  37 #ifndef nsIHTMLContentSink_h___
  38 #define nsIHTMLContentSink_h___
  39
  40 /**
  41  * This file declares the concrete HTMLContentSink class.
  42  * This class is used during the parsing process as the
  43  * primary interface between the parser and the content
  44  * model.
  45  *
  46  * After the tokenizer completes, the parser iterates over
  47  * the known token list. As the parser identifies valid
  48  * elements, it calls the contentsink interface to notify
  49  * the content model that a new node or child node is being
  50  * created and added to the content model.
  51  *
  52  * The HTMLContentSink interface assumes 4 underlying
  53  * containers: HTML, HEAD, BODY and FRAMESET. Before
  54  * accessing any these, the parser will call the appropriate
  55  * OpennsIHTMLContentSink method: OpenHTML,OpenHead,OpenBody,OpenFrameSet;
  56  * likewise, the ClosensIHTMLContentSink version will be called when the
  57  * parser is done with a given section.
  58  *
  59  * IMPORTANT: The parser may Open each container more than
  60  * once! This is due to the irregular nature of HTML files.
  61  * For example, it is possible to encounter plain text at
  62  * the start of an HTML document (that preceeds the HTML tag).
  63  * Such text is treated as if it were part of the body.
  64  * In such cases, the parser will Open the body, pass the text-
  65  * node in and then Close the body. The body will likely be
  66  * re-Opened later when the actual <BODY> tag has been seen.
  67  *
  68  * Containers within the body are Opened and Closed
  69  * using the OpenContainer(...) and CloseContainer(...) calls.
  70  * It is assumed that the document or contentSink is
  71  * maintaining its state to manage where new content should
  72  * be added to the underlying document.
  73  *
  74  * NOTE: OpenHTML() and OpenBody() may get called multiple times
  75  *       in the same document. That's fine, and it doesn't mean
  76  *       that we have multiple bodies or HTML's.
  77  *
  78  * NOTE: I haven't figured out how sub-documents (non-frames)
  79  *       are going to be handled. Stay tuned.
  80  */
  81 #include "nsIParserNode.h"
  82 #include "nsIContentSink.h"
  83 #include "nsHTMLTags.h"
  84
  85 // d19e6730-5e2f-4131-89db-8a918515097d
  86 #define NS_IHTML_CONTENT_SINK_IID \
  87 { 0xd19e6730, 0x5e2f, 0x4131, \
  88   { 0x89, 0xdb, 0x8a, 0x91, 0x85, 0x15, 0x09, 0x7d } }
  89
  90
  91 #if defined(XP_MAC)
  92 #define MAX_REFLOW_DEPTH  75    //setting to 75 to prevent layout from crashing on mac. Bug 55095.
  93 #else
  94 #define MAX_REFLOW_DEPTH  200   //windows and linux (etc) can do much deeper structures.
  95 #endif
  96
  97 class nsIHTMLContentSink : public nsIContentSink
  98 {
  99 public:
 100
 101   NS_DECLARE_STATIC_IID_ACCESSOR(NS_IHTML_CONTENT_SINK_IID)
 102
 103   /**
 104    * This method is used to open the HEAD container. It is useful if a tag
 105    * is forcing us to open the head (probably again), like if we find a <meta>
 106    * tag in the body.
 107    */
 108   NS_IMETHOD OpenHead() = 0;
 109
 110   /**
 111    * This gets called when handling illegal contents, especially
 112    * in dealing with tables. This method creates a new context.
 113    *
 114    * @update 04/04/99 harishd
 115    * @param aPosition - The position from where the new context begins.
 116    */
 117   NS_IMETHOD BeginContext(PRInt32 aPosition) = 0;
 118
 119   /**
 120    * This method terminates any new context that got created by
 121    * BeginContext and switches back to the main context.
 122    *
 123    * @update 04/04/99 harishd
 124    * @param aPosition - Validates the end of a context.
 125    */
 126   NS_IMETHOD EndContext(PRInt32 aPosition) = 0;
 127
 128   /**
 129    * @update 01/09/2003 harishd
 130    * @param aTag - Check if this tag is enabled or not.
 131    */
 132   NS_IMETHOD IsEnabled(PRInt32 aTag, PRBool* aReturn) = 0;
 133
 134   /**
 135    * This method is called when parser has
 136    * completed processing a chunk of tokens. The processing of the
 137    * tokens may be interrupted by returning NS_ERROR_HTMLPARSER_INTERRUPTED from
 138    * DidProcessAToken.
 139    */
 140   NS_IMETHOD DidProcessTokens() = 0;
 141
 142   /**
 143    * This method is called when parser is about to
 144    * process a single token
 145    */
 146   NS_IMETHOD WillProcessAToken(void) = 0;
 147
 148   /**
 149    * This method is called when parser has completed
 150    * the processing for a single token.
 151    * @return NS_OK if processing should not be interrupted
 152    *         NS_ERROR_HTMLPARSER_INTERRUPTED if the parsing should be interrupted
 153    */
 154   NS_IMETHOD DidProcessAToken(void) = 0;
 155
 156     /**
 157    * This method is used to open a generic container in the sink.
 158    *
 159    * @update 4/1/98 gess
 160    * @param  nsIParserNode reference to parser node interface
 161    */
 162   NS_IMETHOD OpenContainer(const nsIParserNode& aNode) = 0;
 163
 164   /**
 165    *  This method gets called by the parser when a close
 166    *  container tag has been consumed and needs to be closed.
 167    *
 168    * @param  aTag - The tag to be closed.
 169    */
 170   NS_IMETHOD CloseContainer(const nsHTMLTag aTag) = 0;
 171
 172   /**
 173    * This method is used when we're closing a tag that was malformed
 174    * in some way. This way, the content sink can do special processing
 175    * (e.g., not execute a malformed script tag).
 176    *
 177    * @param aTag The tag to be closed.
 178    */
 179   NS_IMETHOD CloseMalformedContainer(const nsHTMLTag aTag)
 180   {
 181     return CloseContainer(aTag);
 182   }
 183
 184   /**
 185    * This gets called by the parser when you want to add
 186    * a leaf node to the current container in the content
 187    * model.
 188    *
 189    * @update 4/1/98 gess
 190    * @param  nsIParserNode reference to parser node interface
 191    */
 192   NS_IMETHOD AddLeaf(const nsIParserNode& aNode) = 0;
 193
 194   /**
 195    * This gets called by the parser when you want to add
 196    * a leaf node to the current container in the content
 197    * model.
 198    *
 199    * @update 4/1/98 gess
 200    * @param  nsIParserNode reference to parser node interface
 201    */
 202   NS_IMETHOD AddComment(const nsIParserNode& aNode) = 0;
 203
 204   /**
 205    * This gets called by the parser when you want to add
 206    * a leaf node to the current container in the content
 207    * model.
 208    *
 209    * @update 4/1/98 gess
 210    * @param  nsIParserNode reference to parser node interface
 211    */
 212   NS_IMETHOD AddProcessingInstruction(const nsIParserNode& aNode) = 0;
 213
 214   /**
 215    * This method is called by the parser when it encounters
 216    * a document type declaration.
 217    *
 218    * XXX Should the parser also parse the internal subset?
 219    *
 220    * @param  nsIParserNode reference to parser node interface
 221    */
 222   NS_IMETHOD AddDocTypeDecl(const nsIParserNode& aNode) = 0;
 223
 224   /**
 225    * This gets called by the parser to notify observers of
 226    * the tag
 227    *
 228    * @param aErrorResult the error code
 229    */
 230   NS_IMETHOD NotifyTagObservers(nsIParserNode* aNode) = 0;
 231
 232   /**
 233    * Call this method to determnine if a FORM is on the sink's stack
 234    *
 235    * @return PR_TRUE if found else PR_FALSE
 236    */
 237   NS_IMETHOD_(PRBool) IsFormOnStack() = 0;
 238
 239 };
 240
 241 NS_DEFINE_STATIC_IID_ACCESSOR(nsIHTMLContentSink, NS_IHTML_CONTENT_SINK_IID)
 242
 243 #endif /* nsIHTMLContentSink_h___ */
 244