text;
}
public function characters( $text, $start, $length, $sourceStart, $sourceLength ) {
if ( !$this->insideNonVisibleTag ) {
$this->text .= substr( $text, $start, $length );
}
}
public function startTag( $name, Attributes $attrs, $selfClose, $sourceStart, $sourceLength ) {
if ( $this->isNonVisibleTag( $name ) ) {
$this->insideNonVisibleTag = true;
}
// Inject whitespace for typical block-level tags to
// prevent merging unrelated
words.
if ( $this->isBlockLevelTag( $name ) ) {
$this->text .= ' ';
}
}
public function endTag( $name, $sourceStart, $sourceLength ) {
if ( $this->isNonVisibleTag( $name ) ) {
$this->insideNonVisibleTag = false;
}
// Inject whitespace for typical block-level tags to
// prevent merging unrelated
words.
if ( $this->isBlockLevelTag( $name ) ) {
$this->text .= ' ';
}
}
// Per https://developer.mozilla.org/en-US/docs/Web/HTML/Block-level_elements
// retrieved on sept 12, 2018.
is not block level but was added anyways.
// The following is a complete list of all HTML block level elements
// (although "block-level" is not technically defined for elements that are
// new in HTML5).
// Structured as tag => true to allow O(1) membership test.
private const BLOCK_LEVEL_TAGS = [
'address' => true,
'article' => true,
'aside' => true,
'blockquote' => true,
'br' => true,
'canvas' => true,
'dd' => true,
'div' => true,
'dl' => true,
'dt' => true,
'fieldset' => true,
'figcaption' => true,
'figure' => true,
'footer' => true,
'form' => true,
'h1' => true,
'h2' => true,
'h3' => true,
'h4' => true,
'h5' => true,
'h6' => true,
'header' => true,
'hgroup' => true,
'hr' => true,
'li' => true,
'main' => true,
'nav' => true,
'noscript' => true,
'ol' => true,
'output' => true,
'p' => true,
'pre' => true,
'section' => true,
'table' => true,
'td' => true,
'tfoot' => true,
'th' => true,
'tr' => true,
'ul' => true,
'video' => true,
];
/**
* Detect block level tags. Of course css can make anything a block
* level tag, but this is still better than nothing.
*
* @param string $tagName HTML tag name
* @return bool True when tag is an html block level element
*/
private function isBlockLevelTag( $tagName ) {
$key = strtolower( trim( $tagName ) );
return isset( self::BLOCK_LEVEL_TAGS[$key] );
}
private const NON_VISIBLE_TAGS = [
'style' => true,
'script' => true,
];
/**
* Detect block tags which by default are non-visible items.
* Of course css can make anything non-visible,
* but this is still better than nothing.
*
* We use this primarily to hide TemplateStyles
* from output in notifications/emails etc.
*
* @param string $tagName HTML tag name
* @return bool True when tag is a html element which should be filtered out
*/
private function isNonVisibleTag( $tagName ) {
$key = strtolower( trim( $tagName ) );
return isset( self::NON_VISIBLE_TAGS[$key] );
}
}