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mirror of https://github.com/ezyang/htmlpurifier.git synced 2024-11-09 15:28:40 +00:00

Finally stabilize the unit converter.

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

2
TODO
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@ -17,6 +17,8 @@ afraid to cast your vote for the next feature to be implemented!
- Maintain old attribute data in tokens (configurable?)
- Allow URIFilters to run early?
- Lazy update of token when validating attributes?
- Investigate how early internal structures can be accessed; this would
prevent structures from being parsed and serialized multiple times.
FUTURE VERSIONS
---------------

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@ -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);

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;
}
}

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@ -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;
}
}

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@ -5,14 +5,14 @@ class HTMLPurifier_LengthTest extends HTMLPurifier_Harness
function testConstruct() {
$l = new HTMLPurifier_Length('23', 'in');
$this->assertIdentical($l->n, '23');
$this->assertIdentical($l->unit, 'in');
$this->assertIdentical($l->getN(), '23');
$this->assertIdentical($l->getUnit(), 'in');
}
function testMake() {
$l = HTMLPurifier_Length::make('+23.4in');
$this->assertIdentical($l->n, '+23.4');
$this->assertIdentical($l->unit, 'in');
$this->assertIdentical($l->getN(), '+23.4');
$this->assertIdentical($l->getUnit(), 'in');
}
function testToString() {
@ -23,13 +23,15 @@ class HTMLPurifier_LengthTest extends HTMLPurifier_Harness
protected function assertValidate($string, $expect = true, $disable_negative = false) {
if ($expect === true) $expect = $string;
$l = HTMLPurifier_Length::make($string);
$result = $l->validate($disable_negative, $this->config, $this->context);
$result = $l->isValid($disable_negative);
if ($result === false) $this->assertIdentical($expect, false);
else $this->assertIdentical($l->toString(), $expect);
}
function testValidate() {
$this->assertValidate('0');
$this->assertValidate('+0', '0');
$this->assertValidate('-0', '0');
$this->assertValidate('0px');
$this->assertValidate('4.5px');
$this->assertValidate('-4.5px');

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@ -3,12 +3,35 @@
class HTMLPurifier_UnitConverterTest extends HTMLPurifier_Harness
{
protected function assertConversion($input, $expect) {
$input = HTMLPurifier_Length::make($input);
$expect = HTMLPurifier_Length::make($expect);
protected function assertConversion($input, $expect, $unit = null, $test_negative = true) {
$length = HTMLPurifier_Length::make($input);
if ($expect !== false) $expectl = HTMLPurifier_Length::make($expect);
else $expectl = false;
$converter = new HTMLPurifier_UnitConverter();
$result = $converter->convert($input, $expect->unit);
$this->assertIdentical($result, $expect);
$result = $converter->convert($length, $unit !== null ? $unit : $expectl->getUnit());
$this->assertIdentical($result, $expectl);
if ($test_negative) {
$this->assertConversion(
"-$input",
$expect === false ? false : "-$expect",
$unit,
false
);
}
}
function testFail() {
$this->assertConversion('1in', false, 'foo');
$this->assertConversion('1foo', false, 'in');
}
function testZero() {
$this->assertConversion('0', '0', 'in', false);
$this->assertConversion('-0', '0', 'in', false);
$this->assertConversion('0in', '0', 'in', false);
$this->assertConversion('-0in', '0', 'in', false);
$this->assertConversion('0in', '0', 'pt', false);
$this->assertConversion('-0in', '0', 'pt', false);
}
function testEnglish() {
@ -39,7 +62,8 @@ class HTMLPurifier_UnitConverterTest extends HTMLPurifier_Harness
$this->assertConversion('0.3937in', '1cm');
}
function testRounding() {
function testRoundingMinPrecision() {
// One sig-fig, modified to be four, conversion rounds up
$this->assertConversion('100pt', '1.389in');
$this->assertConversion('1000pt', '13.89in');
$this->assertConversion('10000pt', '138.9in');
@ -47,4 +71,43 @@ class HTMLPurifier_UnitConverterTest extends HTMLPurifier_Harness
$this->assertConversion('1000000pt', '13890in');
}
function testRoundingUserPrecision() {
// Five sig-figs, conversion rounds down
$this->assertConversion('11112000pt', '154330in');
$this->assertConversion('1111200pt', '15433in');
$this->assertConversion('111120pt', '1543.3in');
$this->assertConversion('11112pt', '154.33in');
$this->assertConversion('1111.2pt', '15.433in');
$this->assertConversion('111.12pt', '1.5433in');
$this->assertConversion('11.112pt', '0.15433in');
}
protected function assertSigFig($n, $sigfigs) {
$converter = new HTMLPurifier_UnitConverter();
$result = $converter->getSigFigs($n);
$this->assertIdentical($result, $sigfigs);
}
function test_getSigFigs() {
$this->assertSigFig('0', 0);
$this->assertSigFig('1', 1);
$this->assertSigFig('-1', 1);
$this->assertSigFig('+1', 1);
$this->assertSigFig('01', 1);
$this->assertSigFig('001', 1);
$this->assertSigFig('12', 2);
$this->assertSigFig('012', 2);
$this->assertSigFig('10', 1);
$this->assertSigFig('10.', 2);
$this->assertSigFig('100.', 3);
$this->assertSigFig('103', 3);
$this->assertSigFig('130', 2);
$this->assertSigFig('.1', 1);
$this->assertSigFig('0.1', 1);
$this->assertSigFig('00.1', 1);
$this->assertSigFig('0.01', 1);
$this->assertSigFig('0.010', 2);
$this->assertSigFig('0.012', 2);
}
}