mirror/php-htmlpurifier
1
0
Fork 0
mirror of https://github.com/ezyang/htmlpurifier.git synced 2025-08-04 21:28:06 +02:00
Code Issues Releases Wiki Activity

Finally stabilize the unit converter.

Browse Source 
git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@1750 48356398-32a2-884e-a903-53898d9a118a
This commit is contained in:
Edward Z. Yang
2008-05-20 21:23:38 +00:00
parent fda310f1e7
commit d8da5ff406
6 changed files with 160 additions and 41 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
library/HTMLPurifier/AttrDef/CSS/Number.php
View File

@@ -18,6 +18,10 @@ class HTMLPurifier_AttrDef_CSS_Number extends HTMLPurifier_AttrDef
$this->non_negative = $non_negative;
}
/**
* @warning Some contexts do not pass $config, $context. These
* variables should not be used without checking HTMLPurifier_Length
*/
public function validate($number, $config, $context) {
$number = $this->parseCDATA($number);

40
library/HTMLPurifier/Length.php
View File

@@ -2,7 +2,7 @@
/**
* Represents a measurable length, with a string numeric magnitude
* and a unit.
* and a unit. This object is immutable.
*/
class HTMLPurifier_Length
{
@@ -10,12 +10,17 @@ class HTMLPurifier_Length
/**
* String numeric magnitude.
*/
public $n;
protected $n;
/**
* String unit. False is permitted if $n = 0.
*/
public $unit;
protected $unit;
/**
* Whether or not this length is valid. Null if not calculated yet.
*/
protected $isValid;
/**
* Lookup array of units recognized by CSS 2.1
@@ -30,8 +35,8 @@ class HTMLPurifier_Length
* @param string $u Unit
*/
public function __construct($n = '0', $u = false) {
$this->n = $n;
$this->unit = $u;
$this->n = (string) $n;
$this->unit = $u !== false ? (string) $u : false;
}
/**
@@ -51,13 +56,15 @@ class HTMLPurifier_Length
* @param bool $non_negative Whether or not to disable negative values.
* @note Maybe should be put in another class.
*/
public function validate($non_negative = false, $config, $context) {
protected function validate($non_negative = false) {
// Special case:
if ($this->n === '+0' || $this->n === '-0') $this->n = '0';
if ($this->n === '0' && $this->unit === false) return true;
if (!ctype_lower($this->unit)) $this->unit = strtolower($this->unit);
if (!isset(HTMLPurifier_Length::$allowedUnits[$this->unit])) return false;
// Hack:
$def = new HTMLPurifier_AttrDef_CSS_Number($non_negative);
$result = $def->validate($this->n, $config, $context);
$result = $def->validate($this->n, false, false);
if ($result === false) return false;
$this->n = $result;
return true;
@@ -67,7 +74,26 @@ class HTMLPurifier_Length
* Returns string representation of number.
*/
public function toString() {
if (!$this->isValid()) return false;
return $this->n . $this->unit;
}
/**
* Retrieves string numeric magnitude.
*/
public function getN() {return $this->n;}
/**
* Retrieves string unit.
*/
public function getUnit() {return $this->unit;}
/**
* Returns true if this length unit is valid.
*/
public function isValid($non_negative = false) {
if ($this->isValid === null) $this->isValid = $this->validate($non_negative);
return $this->isValid;
}
}

68
library/HTMLPurifier/UnitConverter.php
View File

@@ -50,6 +50,11 @@ class HTMLPurifier_UnitConverter
/**
* Converts a length object of one unit into another unit.
* @param HTMLPurifier_Length $length
* Instance of HTMLPurifier_Length to convert. You must validate()
* it before passing it here!
* @param string $to_unit
* Unit to convert to.
* @note
* About precision: This conversion function pays very special
* attention to the incoming precision of values and attempts
@@ -60,39 +65,35 @@ class HTMLPurifier_UnitConverter
* - If a number contains less than four sigfigs ($outputPrecision)
* and this causes some decimals to be excluded, those
* decimals will be added on.
* - Significant digits will be ignored for quantities greater
* than one. This is a limitation of BCMath and I don't
* feel like coding around it.
*/
public function convert($length, $to_unit) {
if ($length->n === '0' || $length->unit === false) {
return new HTMLPurifier_Length('0', $unit);
if (!$length->isValid()) return false;
$n = $length->getN();
$unit = $length->getUnit();
if ($n === '0' || $unit === false) {
return new HTMLPurifier_Length('0', false);
}
$state = $dest = false;
$state = $dest_state = false;
foreach (self::$units as $k => $x) {
if (isset($x[$length->unit])) $state = $k;
if (isset($x[$unit])) $state = $k;
if (isset($x[$to_unit])) $dest_state = $k;
}
if (!$state || !$dest_state) return false;
$n = $length->n;
$unit = $length->unit;
// Some calculations about the initial precision of the number;
// this will be useful when we need to do final rounding.
$log = (int) floor(log($n, 10));
if (strpos($n, '.') === false) {
$sigfigs = strlen(trim($n, '0+-'));
} else {
$sigfigs = strlen(ltrim($n, '0+-')) - 1; // eliminate extra decimal character
}
$sigfigs = $this->getSigFigs($n);
if ($sigfigs < $this->outputPrecision) $sigfigs = $this->outputPrecision;
// BCMath's internal precision deals only with decimals. Use
// our default if the initial number has no decimals, or increase
// it by how ever many decimals, thus, the number of guard digits
// will always be greater than or equal to internalPrecision.
$log = (int) floor(log(abs($n), 10));
$cp = ($log < 0) ? $this->internalPrecision - $log : $this->internalPrecision; // internal precision
for ($i = 0; $i < 2; $i++) {
@@ -113,7 +114,7 @@ class HTMLPurifier_UnitConverter
$unit = $dest_unit;
}
// Output was zero, so bail out early
// Output was zero, so bail out early. Shouldn't ever happen.
if ($n === '') {
$n = '0';
$unit = $to_unit;
@@ -148,17 +149,21 @@ class HTMLPurifier_UnitConverter
// Calculate how many decimals we need ($rp)
// Calculations will always be carried to the decimal; this is
// a limitation with BC (we can't set the scale to be negative)
$new_log = (int) floor(log($n, 10));
$new_log = (int) floor(log(abs($n), 10));
$rp = $sigfigs - $new_log - 1;
//echo "----\n";
//echo "$n\nsigfigs = $sigfigs\nnew_log = $new_log\nlog = $log\nrp = $rp\n";
$neg = $n < 0 ? '-' : '';
// Useful for debugging:
//echo "<pre>n";
//echo "$n\nsigfigs = $sigfigs\nnew_log = $new_log\nlog = $log\nrp = $rp\n</pre>\n";
if ($rp >= 0) {
$n = bcadd($n, '0.' . str_repeat('0', $rp) . '5', $rp + 1);
$n = bcadd($n, $neg . '0.' . str_repeat('0', $rp) . '5', $rp + 1);
$n = bcdiv($n, '1', $rp);
} else {
if ($new_log + 1 >= $sigfigs) {
$n = bcadd($n, '5' . str_repeat('0', $new_log - $sigfigs));
$n = substr($n, 0, $sigfigs) . str_repeat('0', $new_log + 1 - $sigfigs);
$n = bcadd($n, $neg . '5' . str_repeat('0', $new_log - $sigfigs));
$n = substr($n, 0, $sigfigs + strlen($neg)) . str_repeat('0', $new_log + 1 - $sigfigs);
}
}
if (strpos($n, '.') !== false) $n = rtrim($n, '0');
@@ -167,4 +172,21 @@ class HTMLPurifier_UnitConverter
return new HTMLPurifier_Length($n, $unit);
}
/**
* Returns the number of significant figures in a string number.
* @param string $n Decimal number
* @return int number of sigfigs
*/
public function getSigFigs($n) {
$n = ltrim($n, '0+-');
$dp = strpos($n, '.'); // decimal position
if ($dp === false) {
$sigfigs = strlen(rtrim($n, '0'));
} else {
$sigfigs = strlen(ltrim($n, '0.')); // eliminate extra decimal character
if ($dp !== 0) $sigfigs--;
}
return $sigfigs;
}
}