Page Speed Optimization Libraries  1.2.24.1
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net_instaweb::HtmlParse Class Reference

#include "html_parse.h"

Inheritance diagram for net_instaweb::HtmlParse:
net_instaweb::RewriteDriver

List of all members.

Public Member Functions

 HtmlParse (MessageHandler *message_handler)
void AddFilter (HtmlFilter *filter)
 Application methods for parsing functions and adding filters.
bool StartParse (const StringPiece &url)
bool StartParseWithType (const StringPiece &url, const ContentType &content_type)
bool is_url_valid () const
 Returns whether the google_url() URL is valid.
virtual bool StartParseId (const StringPiece &url, const StringPiece &id, const ContentType &content_type)
void ParseText (const char *content, int size)
void ParseText (const StringPiece &sp)
virtual void Flush ()
virtual void FinishParse ()
HtmlCdataNodeNewCdataNode (HtmlElement *parent, const StringPiece &contents)
 Utility methods for implementing filters.
HtmlCharactersNodeNewCharactersNode (HtmlElement *parent, const StringPiece &literal)
HtmlCommentNodeNewCommentNode (HtmlElement *parent, const StringPiece &contents)
HtmlDirectiveNodeNewDirectiveNode (HtmlElement *parent, const StringPiece &contents)
HtmlIEDirectiveNodeNewIEDirectiveNode (HtmlElement *parent, const StringPiece &contents)
void InsertElementBeforeElement (const HtmlNode *existing_node, HtmlNode *new_node)
void InsertElementAfterElement (const HtmlNode *existing_node, HtmlNode *new_node)
void PrependChild (const HtmlElement *existing_parent, HtmlNode *new_child)
void AppendChild (const HtmlElement *existing_parent, HtmlNode *new_child)
void InsertElementBeforeCurrent (HtmlNode *new_node)
void InsertElementAfterCurrent (HtmlNode *new_node)
bool AddParentToSequence (HtmlNode *first, HtmlNode *last, HtmlElement *new_parent)
bool MoveCurrentInto (HtmlElement *new_parent)
bool MoveCurrentBefore (HtmlNode *existing_node)
bool DeleteElement (HtmlNode *node)
bool DeleteSavingChildren (HtmlElement *element)
bool HasChildrenInFlushWindow (HtmlElement *element)
bool ReplaceNode (HtmlNode *existing_node, HtmlNode *new_node)
HtmlElementCloneElement (HtmlElement *in_element)
HtmlElementNewElement (HtmlElement *parent, const StringPiece &str)
HtmlElementNewElement (HtmlElement *parent, HtmlName::Keyword keyword)
HtmlElementNewElement (HtmlElement *parent, const HtmlName &name)
void AddAttribute (HtmlElement *element, HtmlName::Keyword keyword, const StringPiece &value)
void AddEscapedAttribute (HtmlElement *element, HtmlName::Keyword keyword, const StringPiece &escaped_value)
void AddAttribute (HtmlElement *element, HtmlName::Keyword keyword, int value)
void SetAttributeName (HtmlElement::Attribute *attribute, HtmlName::Keyword keyword)
HtmlName MakeName (const StringPiece &str)
HtmlName MakeName (HtmlName::Keyword keyword)
bool IsRewritable (const HtmlNode *node) const
void ClearElements ()
void DebugLogQueue ()
 Log the HtmlEvent queue_ to the message_handler_ for debugging.
void DebugPrintQueue ()
 Print the HtmlEvent queue_ to stdout for debugging.
bool IsImplicitlyClosedTag (HtmlName::Keyword keyword) const
bool IsOptionallyClosedTag (HtmlName::Keyword keyword) const
bool TagAllowsBriefTermination (HtmlName::Keyword keyword) const
 Determines whether a tag allows brief termination in HTML, e.g. <tag>
MessageHandlermessage_handler () const
const char * url () const
const GoogleUrlgoogle_url () const
 Gets a parsed GoogleUrl& corresponding to url().
const char * id () const
int line_number () const
GoogleString UrlLine () const
 Returns URL (or id) and line number as a string, to be used in messages.
const DocTypedoctype () const
void Info (const char *filename, int line, const char *msg,...) INSTAWEB_PRINTF_FORMAT(4
 Interface for any caller to report an error message via the message handler.
void void Warning (const char *filename, int line, const char *msg,...) INSTAWEB_PRINTF_FORMAT(4
void void void Error (const char *filename, int line, const char *msg,...) INSTAWEB_PRINTF_FORMAT(4
void void void void FatalError (const char *filename, int line, const char *msg,...) INSTAWEB_PRINTF_FORMAT(4
void void void void void InfoV (const char *file, int line, const char *msg, va_list args)
void WarningV (const char *file, int line, const char *msg, va_list args)
void ErrorV (const char *file, int line, const char *msg, va_list args)
void FatalErrorV (const char *file, int line, const char *msg, va_list args)
void InfoHere (const char *msg,...) INSTAWEB_PRINTF_FORMAT(2
 Report error message with current parsing filename and linenumber.
void void WarningHere (const char *msg,...) INSTAWEB_PRINTF_FORMAT(2
void void void ErrorHere (const char *msg,...) INSTAWEB_PRINTF_FORMAT(2
void void void void FatalErrorHere (const char *msg,...) INSTAWEB_PRINTF_FORMAT(2
void void void void void ShowProgress (const char *message)
void InfoHereV (const char *msg, va_list args)
void WarningHereV (const char *msg, va_list args)
void ErrorHereV (const char *msg, va_list args)
void FatalErrorHereV (const char *msg, va_list args)
void AddElement (HtmlElement *element, int line_number)
void CloseElement (HtmlElement *element, HtmlElement::CloseStyle close_style, int line_number)
void ApplyFilter (HtmlFilter *filter)
 Run a filter on the current queue of parse nodes.
void set_timer (Timer *timer)
void set_log_rewrite_timing (bool x)
void add_event_listener (HtmlFilter *listener)
void InsertComment (const StringPiece &sp)
void set_size_limit (int64 x)
 Sets the limit on the maximum number of bytes that should be parsed.
bool size_limit_exceeded () const
 Returns whether we have exceeded the size limit.

Protected Types

typedef std::vector< HtmlFilter * > FilterVector
typedef std::list< HtmlFilter * > FilterList

Protected Member Functions

void BeginFinishParse ()
void EndFinishParse ()
size_t GetEventQueueSize ()
 Returns the number of events on the event queue.
void AppendEventsToQueue (HtmlEventList *extra_events)
 Move the entire contents of extra_events onto the end of the event queue.
HtmlEventSplitQueueOnFirstEventInSet (const ConstHtmlEventSet &event_set, HtmlEventList *tail)
HtmlEventGetEndElementEvent (const HtmlElement *element)
virtual void ParseTextInternal (const char *content, int size)
void DetermineEnabledFilters (FilterVector *filters) const
 Allow filters to determine whether they are enabled for this request.

Friends

class HtmlLexer
 Implementation helper with detailed knowledge of html parsing libraries.
class HtmlTestingPeer
 Visible for testing only, via HtmlTestingPeer.

Detailed Description

Todo:
TODO(jmarantz): rename HtmlParse to HtmlContext. The actual parsing occurs in HtmlLexer, and this class is dominated by methods to manipulate DOM as it streams through.

Member Function Documentation

Adds a filter to be called during parsing as new events are added. Takes ownership of the HtmlFilter passed in.

Application methods for parsing functions and adding filters.

Add a new html filter to the filter-chain, without taking ownership of it.

bool net_instaweb::HtmlParse::AddParentToSequence ( HtmlNode first,
HtmlNode last,
HtmlElement new_parent 
)

Enclose element around two elements in a sequence. The first element must be the same as, or precede the last element in the event-stream, and this is not checked, but the two elements do not need to be adjacent. They must have the same parent to start with.

HtmlParse::FinishParse() is equivalent to the sequence of BeginFinishParse(); Flush(); EndFinishParse(). Split up to permit asynchronous versions.

Creates an another element with the same name and attributes as in_element. Does not duplicate the children or insert it anywhere.

If the given node is rewritable, delete it and all of its children (if any) and return true; otherwise, do nothing and return false. Note: Javascript appears to use removeChild for this.

Delete a parent element, retaining any children and moving them to reside under the parent's parent.

Return the current assumed doctype of the document (based on the content type and any HTML directives encountered so far).

virtual void net_instaweb::HtmlParse::FinishParse ( ) [virtual]

Finish a chunked parsing session. This also induces a Flush.

It is invalid to call FinishParse when the StartParse* routines returned false.

Reimplemented in net_instaweb::RewriteDriver.

virtual void net_instaweb::HtmlParse::Flush ( ) [virtual]

Flush the currently queued events through the filters. It is desirable for large web pages, particularly dynamically generated ones, to start getting delivered to the browser as soon as they are ready. On the other hand, rewriting is more powerful when more of the content can be considered for image/css/js spriting. This method should be called when the controlling network process wants to induce a new chunk of output. The less you call this function the better the rewriting will be.

It is invalid to call Flush when the StartParse* routines returned false.

If this is called from a Filter, the request will be deferred until after currently active filters are completed.

Reimplemented in net_instaweb::RewriteDriver.

Return the EndElementEvent for this element, or NULL if it doesn't exist yet.

Determines whether the element, in the context of its flush window, has children. If the element is not rewritable, or has not been closed yet, or inserted into the DOM event stream, then 'false' is returned.

Note that the concept of the Flush Window is important because the knowledge of an element's children is not limited to the current event being presented to a Filter. A Filter can call this method in the StartElement of an event to see if any children are going to be coming. Of course, if the StartElement is at the end of a Flush window, then we won't know about the children, but IsRewritable will also be false.

void net_instaweb::HtmlParse::InsertComment ( const StringPiece &  sp)

Inserts a comment before or after the current node. The function tries to pick an intelligent place depending on the document structure and whether the current node is a start-element, end-element, or a leaf.

Insert a new element after the current one, moving current_ to the new element. In a Filter, the flush-loop will advance past this on the next iteration. Note: new_node must not already be in the DOM.

Insert a new element before the current one. current_ remains unchanged. Note: new_node must not already be in the DOM.

void net_instaweb::HtmlParse::InsertElementBeforeElement ( const HtmlNode existing_node,
HtmlNode new_node 
)

DOM-manipulation methods.

Todo:
TODO(sligocki): Find Javascript equivalents and list them or even change our names to be consistent.
Todo:
TODO(mdsteele): Rename these methods to e.g. InsertNodeBeforeNode. This and downstream filters will then see inserted elements but upstream filters will not. Note: In Javascript the first is called insertBefore and takes the arg in the opposite order. Note: new_node must not already be in the DOM.

Determines whether a tag should be terminated in HTML, e.g. <meta ..>. We do not expect to see a close-tag for meta and should never insert one.

An optionally closed tag ranges from

, which is typically not closed, but we infer the closing from context. Also consider <html>, which usually is closed but not always. E.g. www.google.com does not close its html tag.

Moves current node (and all children) directly before existing_node. Note: Will not work if called from StartElement() event.

This differs from InsertElementBeforeElement() because it moves the current node, which is already in the DOM, rather than adding a new node.

Moves current node (and all children) to an already-existing parent, where they will be placed as the last elements in that parent. Returns false if the operation could not be performed because either the node or its parent was partially or wholly flushed. Note: Will not work if called from StartElement() event.

This differs from AppendChild() because it moves the current node, which is already in the DOM, rather than adding a new node.

void net_instaweb::HtmlParse::ParseText ( const char *  content,
int  size 
) [inline]

Parses an arbitrary block of an html file, queuing up the events. Call Flush to send the events through the Filter.

To parse an entire file, first call StartParse(), then call ParseText on the file contents (in whatever size chunks are convenient), then call FinishParse().

It is invalid to call ParseText when the StartParse* routines returned false.

void net_instaweb::HtmlParse::PrependChild ( const HtmlElement existing_parent,
HtmlNode new_child 
)

Add a new child element at the beginning or end of existing_parent's children. Named after Javascript's appendChild method. Note: new_child must not already be in the DOM.

bool net_instaweb::HtmlParse::ReplaceNode ( HtmlNode existing_node,
HtmlNode new_node 
)

If possible, replace the existing node with the new node and return true; otherwise, do nothing and return false.

void net_instaweb::HtmlParse::set_timer ( Timer timer) [inline]

Provide timer to helping to report timing of each filter. You must also set_log_rewrite_timing(true) to turn on this reporting.

void void void void void net_instaweb::HtmlParse::ShowProgress ( const char *  message)

If set_log_rewrite_timing(true) has been called, logs the given message at info level with a timeset offset from the parsing start time,

HtmlEvent* net_instaweb::HtmlParse::SplitQueueOnFirstEventInSet ( const ConstHtmlEventSet &  event_set,
HtmlEventList *  tail 
) [protected]

Move the entire event queue after the first event in event_set to the end of tail. Return that event, or NULL if there was none.

bool net_instaweb::HtmlParse::StartParse ( const StringPiece &  url) [inline]

Initiate a chunked parsing session. Finish with FinishParse. The url is only used to resolve relative URLs; the contents are not directly fetched. The caller must supply the text and call ParseText.

Returns whether the URL is valid.

virtual bool net_instaweb::HtmlParse::StartParseId ( const StringPiece &  url,
const StringPiece &  id,
const ContentType content_type 
) [virtual]

Mostly useful for file-based rewriters so that messages can reference the HTML file and produce navigable errors.

Returns whether the URL is valid.

Reimplemented in net_instaweb::RewriteDriver.

const char* net_instaweb::HtmlParse::url ( ) const [inline]

Gets the current location information; typically to help with error messages.


The documentation for this class was generated from the following file:
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