Here's a different approach to search result keyword highlighting that will match all keyword sub strings in a case insensitive manner and preserve case in the returned text. This solution first grabs all matches within $haystack in a case insensitive manner, and the secondly loops through each of those matched sub strings and applies a case sensitive replace in $haystack. This way each unique (in terms of case) instance of $needle is operated on individually allowing a case sensitive replace to be done in order to preserve the original case of each unique instance of $needle.
<?php
function highlightStr($haystack, $needle, $highlightColorValue) {
// return $haystack if there is no highlight color or strings given, nothing to do.
if (strlen($highlightColorValue) < 1 || strlen($haystack) < 1 || strlen($needle) < 1) {
return $haystack;
}
preg_match_all("/$needle+/i", $haystack, $matches);
if (is_array($matches[0]) && count($matches[0]) >= 1) {
foreach ($matches[0] as $match) {
$haystack = str_replace($match, '<span style="background-color:'.$highlightColorValue.';">'.$match.'</span>', $haystack);
}
}
return $haystack;
}
?>
Description
str_ireplace(
array|string
array|string
string|array
int
): string|array
array|string
$search,array|string
$replace,string|array
$subject,int
&$count = null): string|array
This function returns a string or an array with all occurrences of
search in subject
(ignoring case) replaced with the given replace
value.
To replace text based on a pattern rather than a fixed string,
use preg_replace() with the i
pattern modifier.
Parameters
If search and replace are
arrays, then str_ireplace() takes a value from each
array and uses them to search and replace on
subject. If replace has fewer
values than search, then an empty string is used for
the rest of replacement values. If search is an
array and replace is a string, then this replacement
string is used for every value of search. The
converse would not make sense, though.
If search or replace
are arrays, their elements are processed first to last.
-
search -
The value being searched for, otherwise known as the needle. An array may be used to designate multiple needles.
-
replace -
The replacement value that replaces found
searchvalues. An array may be used to designate multiple replacements. -
subject -
The string or array being searched and replaced on, otherwise known as the haystack.
If
subjectis an array, then the search and replace is performed with every entry ofsubject, and the return value is an array as well. -
count -
If passed, this will be set to the number of replacements performed.
Return Values
Returns a string or an array of replacements.
Changelog
| Version | Description |
|---|---|
| 8.2.0 | Case folding no longer depends on the locale set with setlocale(). Only ASCII case folding will be done. Non-ASCII bytes will be compared by their byte value. |
Examples
Example #1 str_ireplace() example
<?php
$bodytag = str_ireplace("%body%", "black", "<body text=%BODY%>");
echo $bodytag; // <body text=black>
?>Notes
Note: This function is binary-safe.
Caution
Replacement order gotcha
Because str_ireplace() replaces left to right, it might replace a previously inserted value when doing multiple replacements. Example #2 in the str_replace() documentation demonstrates how this may affect you in practice.
See Also
- str_replace() - Replace all occurrences of the search string with the replacement string
- preg_replace() - Perform a regular expression search and replace
- strtr() - Translate characters or replace substrings
add a note
User Contributed Notes 11 notes
sawdust ¶
16 years ago
daevid at daevid dot com ¶
19 years ago
here's a neat little function I whipped up to do HTML color coding of SQL strings.
<?php
/**
* Output the HTML debugging string in color coded glory for a sql query
* This is very nice for being able to see many SQL queries
* @access public
* @return void. prints HTML color coded string of the input $query.
* @param string $query The SQL query to be executed.
* @author Daevid Vincent [daevid@LockdownNetworks.com]
* @version 1.0
* @date 04/05/05
* @todo highlight SQL functions.
*/
function SQL_DEBUG( $query )
{
if( $query == '' ) return 0;
global $SQL_INT;
if( !isset($SQL_INT) ) $SQL_INT = 0;
//[dv] this has to come first or you will have goofy results later.
$query = preg_replace("/['\"]([^'\"]*)['\"]/i", "'<FONT COLOR='#FF6600'>$1</FONT>'", $query, -1);
$query = str_ireplace(
array (
'*',
'SELECT ',
'UPDATE ',
'DELETE ',
'INSERT ',
'INTO',
'VALUES',
'FROM',
'LEFT',
'JOIN',
'WHERE',
'LIMIT',
'ORDER BY',
'AND',
'OR ', //[dv] note the space. otherwise you match to 'COLOR' ;-)
'DESC',
'ASC',
'ON '
),
array (
"<FONT COLOR='#FF6600'><B>*</B></FONT>",
"<FONT COLOR='#00AA00'><B>SELECT</B> </FONT>",
"<FONT COLOR='#00AA00'><B>UPDATE</B> </FONT>",
"<FONT COLOR='#00AA00'><B>DELETE</B> </FONT>",
"<FONT COLOR='#00AA00'><B>INSERT</B> </FONT>",
"<FONT COLOR='#00AA00'><B>INTO</B></FONT>",
"<FONT COLOR='#00AA00'><B>VALUES</B></FONT>",
"<FONT COLOR='#00AA00'><B>FROM</B></FONT>",
"<FONT COLOR='#00CC00'><B>LEFT</B></FONT>",
"<FONT COLOR='#00CC00'><B>JOIN</B></FONT>",
"<FONT COLOR='#00AA00'><B>WHERE</B></FONT>",
"<FONT COLOR='#AA0000'><B>LIMIT</B></FONT>",
"<FONT COLOR='#00AA00'><B>ORDER BY</B></FONT>",
"<FONT COLOR='#0000AA'><B>AND</B></FONT>",
"<FONT COLOR='#0000AA'><B>OR</B> </FONT>",
"<FONT COLOR='#0000AA'><B>DESC</B></FONT>",
"<FONT COLOR='#0000AA'><B>ASC</B></FONT>",
"<FONT COLOR='#00DD00'><B>ON</B> </FONT>"
),
$query
);
echo "<FONT COLOR='#0000FF'><B>SQL[".$SQL_INT."]:</B> ".$query."<FONT COLOR='#FF0000'>;</FONT></FONT><BR>\n";
$SQL_INT++;
} //SQL_DEBUG
?>
Anteaus ¶
9 years ago
If you follow the instructions given here you will end up with code which works in php5.3 but which bugs-out in php5.4. Reason is that '&$count' (explicit pass by reference) is now an illegal construct.
Nasty, especially it leads to unreliable code which may work on test but not in production. Manual needs corrected!
aidan at php dot net ¶
20 years ago
This functionality is now implemented in the PEAR package PHP_Compat.
More information about using this function without upgrading your version of PHP can be found on the below link:
http://pear.php.net/package/PHP_Compat
stepanic dot matija at gmail dot com ¶
14 years ago
FIX-ed problem with highlighting second 'o' OR 'a', in this string
<?php
function highlight_string ($haystack, $needle, $highlight_class) {
// return $haystack if there is no highlight color or strings given, nothing to do.
$first_encode='XXXXXXXXXXXXXXX'; //ENCODE string
$second_encode='YYYYYYYYYYYYYYY';
preg_match_all("/$needle+/i", $haystack, $matches);
if (is_array($matches[0]) && count($matches[0]) >= 1) {
foreach ($matches[0] as $match) {
$haystack = str_replace($match, $first_encode.$match.$second_encode, $haystack);
}
}
$haystack=str_replace(array($first_encode,$second_encode),
array('<font class="'.$highlight_class.'" >','</font>'),$haystack);
return $haystack;
}
?>
Psudo - thepsudo at gmail dot com ¶
13 years ago
For highlighting without the overhead of regex and without destroying capitalization, try this:
<?php
function highlight($needle, $haystack){
$ind = stripos($haystack, $needle);
$len = strlen($needle);
if($ind !== false){
return substr($haystack, 0, $ind) . "<b>" . substr($haystack, $ind, $len) . "</b>" .
highlight($needle, substr($haystack, $ind + $len));
} else return $haystack;
}
?>
This example uses HTML bold tags, but you can easily change the highlighting method.
Michael dot Bond at mail dot wvu dot edu ¶
16 years ago
This function will highlight search terms (Key Words in Context).
The difference between this one and the ones below is that it will preserve the original case of the search term as well. So, if you search for "american" but in the original string it is "American" it will retain the capital "A" as well as the correct case for the rest of the string.
<?php
function kwic($str1,$str2) {
$kwicLen = strlen($str1);
$kwicArray = array();
$pos = 0;
$count = 0;
while($pos !== FALSE) {
$pos = stripos($str2,$str1,$pos);
if($pos !== FALSE) {
$kwicArray[$count]['kwic'] = substr($str2,$pos,$kwicLen);
$kwicArray[$count++]['pos'] = $pos;
$pos++;
}
}
for($I=count($kwicArray)-1;$I>=0;$I--) {
$kwic = '<span class="kwic">'.$kwicArray[$I]['kwic'].'</span>';
$str2 = substr_replace($str2,$kwic,$kwicArray[$I]['pos'],$kwicLen);
}
return($str2);
}
?>
hfuecks at nospam dot org ¶
19 years ago
Note that character case is being defined by your server's locale setting, which effects strings containing non-ASCII characters.
See strtolower() - http://www.php.net/strtolower and comments - internally str_ireplace converts $search and $replace to lowercase to find matches.
holblin at holblin dot com ¶
13 years ago
Warning with highlighting ...
I used :
<?php
$text = preg_replace('/('.$q.')/i','<span class=highlighting "">$1</span>' , $text);
?>
Because this line do not allow to highlight uppercase and lowercase correctly (transform uppercase to lowercase for exemple)
<?php
$text = str_ireplace( $q , '<span class=highlighting "">'.$q.'</span>', $text);
?>
But when $q contain some regex you have some problems ... for exemple :
<?php $q = '('; ?>
So you must use preg_replace to highlight correctly the text and you must create a function for escape bad regex caracters !
I think that a better function can be found but this works I guess :
<?php
function regex_escape( $q )
{
return preg_replace('/([\[\]\(\)\{\}\-\.\*\?\|\^\$])/', '\$1', $q);
}
?>
triplepoint at gmail dot com ¶
14 years ago
Regarding maintaining the case of the find/replace for search-highlighting purposes:
if the performance hit of a regular expression isn't a big problem, there's something like:
<?php
function highlight_matches($find_text, $text) {
return preg_replace("/($find_text)/i", '<span class="search_item">$1</span>', $text);
}
?>
