JString/valid
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< API16:JString
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Description[edit]
Tests a string as to whether it's valid UTF-8 and supported by the Unicode standard Note: this function has been modified to simple return true or false <hsivonen@iki.fi>
Template:Description:JString/valid
Syntax[edit]
static valid($str)| Parameter Name | Default Value | Description |
|---|---|---|
| $str | UTF-8 encoded string |
Returns[edit]
boolean true if valid
Defined in[edit]
libraries/joomla/utilities/string.php
Importing[edit]
jimport( 'joomla.utilities.string' );Source Body[edit]
public static function valid($str)
{
$mState = 0; // cached expected number of octets after the current octet
// until the beginning of the next UTF8 character sequence
$mUcs4 = 0; // cached Unicode character
$mBytes = 1; // cached expected number of octets in the current sequence
$len = strlen($str);
for ($i = 0; $i < $len; $i++)
{
$in = ord($str{$i});
if ($mState == 0)
{
// When mState is zero we expect either a US-ASCII character or a
// multi-octet sequence.
if (0 == (0x80 & ($in))) {
// US-ASCII, pass straight through.
$mBytes = 1;
} else if (0xC0 == (0xE0 & ($in))) {
// First octet of 2 octet sequence
$mUcs4 = ($in);
$mUcs4 = ($mUcs4 & 0x1F) << 6;
$mState = 1;
$mBytes = 2;
} else if (0xE0 == (0xF0 & ($in))) {
// First octet of 3 octet sequence
$mUcs4 = ($in);
$mUcs4 = ($mUcs4 & 0x0F) << 12;
$mState = 2;
$mBytes = 3;
} else if (0xF0 == (0xF8 & ($in))) {
// First octet of 4 octet sequence
$mUcs4 = ($in);
$mUcs4 = ($mUcs4 & 0x07) << 18;
$mState = 3;
$mBytes = 4;
} else if (0xF8 == (0xFC & ($in))) {
/* First octet of 5 octet sequence.
*
* This is illegal because the encoded codepoint must be either
* (a) not the shortest form or
* (b) outside the Unicode range of 0-0x10FFFF.
* Rather than trying to resynchronize, we will carry on until the end
* of the sequence and let the later error handling code catch it.
*/
$mUcs4 = ($in);
$mUcs4 = ($mUcs4 & 0x03) << 24;
$mState = 4;
$mBytes = 5;
} else if (0xFC == (0xFE & ($in))) {
// First octet of 6 octet sequence, see comments for 5 octet sequence.
$mUcs4 = ($in);
$mUcs4 = ($mUcs4 & 1) << 30;
$mState = 5;
$mBytes = 6;
} else {
/* Current octet is neither in the US-ASCII range nor a legal first
* octet of a multi-octet sequence.
*/
return FALSE;
}
}
else
{
// When mState is non-zero, we expect a continuation of the multi-octet
// sequence
if (0x80 == (0xC0 & ($in)))
{
// Legal continuation.
$shift = ($mState - 1) * 6;
$tmp = $in;
$tmp = ($tmp & 0x0000003F) << $shift;
$mUcs4 |= $tmp;
if (0 == --$mState)
{
/*
* Check for illegal sequences and codepoints.
*/
// From Unicode 3.1, non-shortest form is illegal
if (((2 == $mBytes) && ($mUcs4 < 0x0080)) ||
((3 == $mBytes) && ($mUcs4 < 0x0800)) ||
((4 == $mBytes) && ($mUcs4 < 0x10000)) ||
(4 < $mBytes) ||
// From Unicode 3.2, surrogate characters are illegal
(($mUcs4 & 0xFFFFF800) == 0xD800) ||
// Codepoints outside the Unicode range are illegal
($mUcs4 > 0x10FFFF)) {
return FALSE;
}
// Initialize UTF8 cache.
$mState = 0;
$mUcs4 = 0;
$mBytes = 1;
}
}
else
{
return FALSE;
}
}
}
return TRUE;
}[Edit See Also] Template:SeeAlso:JString/valid
Examples[edit]
<CodeExamplesForm />