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htmlpurifier/library/HTMLPurifier/Injector/AutoParagraph.php
Edward Z. Yang fa413e96ac Implement Injector->handleEnd, with lots of refactoring for injector.
Previous design of injector streaming involved editability only to start, empty
and text tokens, because they could be safely modified without causing formedness
errors.  By modifying notifyEnd to operate before MakeWellFormed's safeguards
kick into effect, it can be converted into a handle function, allowing for
arbitrary modification of end tags.

This change involved quite a bit of restructuring of the MakeWellFormed code,
including the moving of end of document tags to inside the loop, so rewinding
on those tags would be functional, increased reuse of the end tag codepath by
code that inserts end tags (as they could be changed out from under you), and
processToken modified to have an extra parameter to force re-processing of
a token if the original token was an end token.

We're not exactly sure if handleEnd works at this point, but the important
talking point about this refactoring is that nothing else broke. Also, a number
of convenience functions were moved from AutoParagraph to the Injector
supertype (specifically: forward, forwardToEndToken, backward, and current).

Signed-off-by: Edward Z. Yang <edwardzyang@thewritingpot.com>
2008-10-01 00:54:51 -04:00

340 lines
13 KiB
PHP

<?php
/**
* Injector that auto paragraphs text in the root node based on
* double-spacing.
* @todo Ensure all states are unit tested, including variations as well.
* @todo Make a graph of the flow control for this Injector.
*/
class HTMLPurifier_Injector_AutoParagraph extends HTMLPurifier_Injector
{
public $name = 'AutoParagraph';
public $needed = array('p');
private function _pStart() {
$par = new HTMLPurifier_Token_Start('p');
$par->armor['MakeWellFormed_TagClosedError'] = true;
return $par;
}
public function handleText(&$token) {
$text = $token->data;
// Does the current parent allow <p> tags?
if ($this->allowsElement('p')) {
if (empty($this->currentNesting) || strpos($text, "\n\n") !== false) {
// Note that we have differing behavior when dealing with text
// in the anonymous root node, or a node inside the document.
// If the text as a double-newline, the treatment is the same;
// if it doesn't, see the next if-block if you're in the document.
$i = $nesting = null;
if (!$this->forwardUntilEndToken($i, $current, $nesting) && $token->is_whitespace) {
// State 1.1: ... ^ (whitespace, then document end)
// ----
// This is a degenerate case
} else {
// State 1.2: PAR1
// ----
// State 1.3: PAR1\n\nPAR2
// ------------
// State 1.4: <div>PAR1\n\nPAR2 (see State 2)
// ------------
$token = array($this->_pStart());
$this->_splitText($text, $token);
}
} else {
// State 2: <div>PAR1... (similar to 1.4)
// ----
// We're in an element that allows paragraph tags, but we're not
// sure if we're going to need them.
if ($this->_pLookAhead()) {
// State 2.1: <div>PAR1<b>PAR1\n\nPAR2
// ----
// Note: This will always be the first child, since any
// previous inline element would have triggered this very
// same routine, and found the double newline. One possible
// exception would be a comment.
$token = array($this->_pStart(), $token);
} else {
// State 2.2.1: <div>PAR1<div>
// ----
// State 2.2.2: <div>PAR1<b>PAR1</b></div>
// ----
}
}
// Is the current parent a <p> tag?
} elseif (
!empty($this->currentNesting) &&
$this->currentNesting[count($this->currentNesting)-1]->name == 'p'
) {
// State 3.1: ...<p>PAR1
// ----
// State 3.2: ...<p>PAR1\n\nPAR2
// ------------
$token = array();
$this->_splitText($text, $token);
// Abort!
} else {
// State 4.1: ...<b>PAR1
// ----
// State 4.2: ...<b>PAR1\n\nPAR2
// ------------
}
}
public function handleElement(&$token) {
// We don't have to check if we're already in a <p> tag for block
// tokens, because the tag would have been autoclosed by MakeWellFormed.
if ($this->allowsElement('p')) {
if (!empty($this->currentNesting)) {
if ($this->_isInline($token)) {
// State 1: <div>...<b>
// ---
// Check if this token is adjacent to the parent token
// (seek backwards until token isn't whitespace)
$i = null;
$this->backward($i, $prev);
if (!$prev instanceof HTMLPurifier_Token_Start) {
// Token wasn't adjacent
if (
$prev instanceof HTMLPurifier_Token_Text &&
substr($prev->data, -2) === "\n\n"
) {
// State 1.1.4: <div><p>PAR1</p>\n\n<b>
// ---
// Quite frankly, this should be handled by splitText
$token = array($this->_pStart(), $token);
} else {
// State 1.1.1: <div><p>PAR1</p><b>
// ---
// State 1.1.2: <div><br /><b>
// ---
// State 1.1.3: <div>PAR<b>
// ---
}
} else {
// State 1.2.1: <div><b>
// ---
// Lookahead to see if <p> is needed.
if ($this->_pLookAhead()) {
// State 1.3.1: <div><b>PAR1\n\nPAR2
// ---
$token = array($this->_pStart(), $token);
} else {
// State 1.3.2: <div><b>PAR1</b></div>
// ---
// State 1.3.3: <div><b>PAR1</b><div></div>\n\n</div>
// ---
}
}
} else {
// State 2.3: ...<div>
// -----
}
} else {
if ($this->_isInline($token)) {
// State 3.1: <b>
// ---
// This is where the {p} tag is inserted, not reflected in
// inputTokens yet, however.
$token = array($this->_pStart(), $token);
} else {
// State 3.2: <div>
// -----
}
$i = null;
if ($this->backward($i, $prev)) {
if (
!$prev instanceof HTMLPurifier_Token_Text
) {
// State 3.1.1: ...</p>{p}<b>
// ---
// State 3.2.1: ...</p><div>
// -----
if (!is_array($token)) $token = array($token);
array_unshift($token, new HTMLPurifier_Token_Text("\n\n"));
} else {
// State 3.1.2: ...</p>\n\n{p}<b>
// ---
// State 3.2.2: ...</p>\n\n<div>
// -----
// Note: PAR<ELEM> cannot occur because PAR would have been
// wrapped in <p> tags.
}
}
}
} else {
// State 2.2: <ul><li>
// ----
// State 2.4: <p><b>
// ---
}
}
/**
* Splits up a text in paragraph tokens and appends them
* to the result stream that will replace the original
* @param $data String text data that will be processed
* into paragraphs
* @param $result Reference to array of tokens that the
* tags will be appended onto
* @param $config Instance of HTMLPurifier_Config
* @param $context Instance of HTMLPurifier_Context
*/
private function _splitText($data, &$result) {
$raw_paragraphs = explode("\n\n", $data);
$paragraphs = array(); // without empty paragraphs
$needs_start = false;
$needs_end = false;
$c = count($raw_paragraphs);
if ($c == 1) {
// There were no double-newlines, abort quickly. In theory this
// should never happen.
$result[] = new HTMLPurifier_Token_Text($data);
return;
}
for ($i = 0; $i < $c; $i++) {
$par = $raw_paragraphs[$i];
if (trim($par) !== '') {
$paragraphs[] = $par;
} else {
if ($i == 0) {
// Double newline at the front
if (empty($result)) {
// The empty result indicates that the AutoParagraph
// injector did not add any start paragraph tokens.
// This means that we have been in a paragraph for
// a while, and the newline means we should start a new one.
$result[] = new HTMLPurifier_Token_End('p');
$result[] = new HTMLPurifier_Token_Text("\n\n");
// However, the start token should only be added if
// there is more processing to be done (i.e. there are
// real paragraphs in here). If there are none, the
// next start paragraph tag will be handled by the
// next call to the injector
$needs_start = true;
} else {
// We just started a new paragraph!
// Reinstate a double-newline for presentation's sake, since
// it was in the source code.
array_unshift($result, new HTMLPurifier_Token_Text("\n\n"));
}
} elseif ($i + 1 == $c) {
// Double newline at the end
// There should be a trailing </p> when we're finally done.
$needs_end = true;
}
}
}
// Check if this was just a giant blob of whitespace. Move this earlier,
// perhaps?
if (empty($paragraphs)) {
return;
}
// Add the start tag indicated by \n\n at the beginning of $data
if ($needs_start) {
$result[] = $this->_pStart();
}
// Append the paragraphs onto the result
foreach ($paragraphs as $par) {
$result[] = new HTMLPurifier_Token_Text($par);
$result[] = new HTMLPurifier_Token_End('p');
$result[] = new HTMLPurifier_Token_Text("\n\n");
$result[] = $this->_pStart();
}
// Remove trailing start token; Injector will handle this later if
// it was indeed needed. This prevents from needing to do a lookahead,
// at the cost of a lookbehind later.
array_pop($result);
// If there is no need for an end tag, remove all of it and let
// MakeWellFormed close it later.
if (!$needs_end) {
array_pop($result); // removes \n\n
array_pop($result); // removes </p>
}
}
/**
* Returns true if passed token is inline (and, ergo, allowed in
* paragraph tags)
*/
private function _isInline($token) {
return isset($this->htmlDefinition->info['p']->child->elements[$token->name]);
}
/**
* Looks ahead in the token list and determines whether or not we need
* to insert a <p> tag.
*/
private function _pLookAhead() {
$this->current($i, $current);
if ($current instanceof HTMLPurifier_Token_Start) $nesting = 1;
else $nesting = 0;
$ok = false;
while ($this->forwardUntilEndToken($i, $current, $nesting)) {
$result = $this->_checkNeedsP($current);
if ($result !== null) {
$ok = $result;
break;
}
}
return $ok;
}
/**
* Determines if a particular token requires an earlier inline token
* to get a paragraph. This should be used with _forwardUntilEndToken
*/
private function _checkNeedsP($current) {
if ($current instanceof HTMLPurifier_Token_Start){
if (!$this->_isInline($current)) {
// <div>PAR1<div>
// ----
// Terminate early, since we hit a block element
return false;
}
} elseif ($current instanceof HTMLPurifier_Token_Text) {
if (strpos($current->data, "\n\n") !== false) {
// <div>PAR1<b>PAR1\n\nPAR2
// ----
return true;
} else {
// <div>PAR1<b>PAR1...
// ----
}
}
return null;
}
}