how to highlight search results - php

Question

hello i have a search function in that i will search a db for keywords. i would like to highlight the keywords and found a second function that i would like to implement into my search function.
so i have this code for the search:
<?php
function searchText($keywords){
global $db;
$returned_results = array();
$where2 = "";
$keywords = preg_split('/[\s]+/', $keywords);
$total_keywords = count($keywords);
foreach ($keywords as $key=>$keyword){
$where2 .= "`column` LIKE '%$keyword%'";
if ($key != ($total_keywords - 1)){
$where2 .= " OR ";
}
}
$results_text = "SELECT `a`, `b`, LEFT(`c`, 150) as `c` FROM `table` WHERE $where2";
$results_num_text = ($query2 = mysqli_query($db, $results_text)) ? mysqli_num_rows($query2) : 0;
if ($results_num_text === 0){
return false;
} else {
while ($row = mysqli_fetch_assoc($query2)){
$returned_results[] = array(
'ab' => $row['ab'],
'cd' => $row['cd'],
);
}
return $returned_results;
}
}
?>
and would like to implement a second function into it:
<?php
function mark_words ($text, $words, $colors = false)
{
if (!$colors || !is_array($colors) ) {
$colors = array('#ff9999', '#ffff99', '#ff99ff', '#99ffff','#99ff99');
}
$c = 0;
foreach ($words as $w) {
$w = preg_quote(trim($w));
if($w=='') {
continue;
}
$regexp = "/($w)(?![^<]+>)/i";
$replacement = '<b style="background-color:'.$colors[$c].'">\\1</b>';
$text = preg_replace ($regexp,$replacement ,$text);
$c++;
if ($c >= count($colors)) {
$c=0;
}
}
return $text;
}
$example = <<< EOT
some text is here inside
EOT;
$search = array('some','is', 'inside');
echo mark_words($example, $search);
?>
so i have this code that doesnt work:
<?php
function searchText($keywords, $colors = false){
global $db;
if (!$colors || !is_array($colors) ) {
$colors = array('#ff9999', '#ffff99', '#ff99ff', '#99ffff','#99ff99');
}
$c = 0;
$returned_results = array();
$where2 = "";
$keywords = preg_split('/[\s]+/', $keywords);
$total_keywords = count($keywords);
foreach ($keywords as $key=>$keyword){
$regexp = "/($w)(?![^<]+>)/i";
$replacement = '<b style="background-color:'.$colors[$c].'">\\1</b>';
$text = preg_replace($regexp,$replacement ,$keywords);
$c++;
if ($c >= count($colors)) {
$c=0;
}
$where2 .= "`b` LIKE '%$keyword%'";
if ($key != ($total_keywords - 1)){
$where2 .= " OR ";
}
}
$results_text = "SELECT `a`, LEFT(`b`, 150) as `b`, `c` FROM `table` WHERE $where2";
$results_num_text = ($query2 = mysqli_query($db, $results_text)) ? mysqli_num_rows($query2) : 0;
if ($results_num_text === 0){
return false;
} else {
while ($row = mysqli_fetch_assoc($query2)){
$returned_results[] = array(
'ab' => $row['a'],
'cd' => $row['b'],
);
}
return $returned_results;
$highlight = array($keywords);
echo mark_words($highlight);
}
}
?>
as i looked for it how to do so i found two possibilities. the first would be a function the second would be directly to highlight it from the select query:
SELECT
REPLACE(`col`, 'foobar', '<span class="highlight">foobar</span>') AS `formated_foobar`
FROM
…
WHERE
`col` LIKE "%foobar%"
so my question is how can i implement the second function into the search function or would it be better to use the second method?
if there is someone who could help me i really would appreciate. thanks a lot.

Answer 1

You shouldn't make it too hard for yourself. All you need it to replace every occurrence of a word with the word wrapped in the span with the required style applied. This should work for you:
function highlight_word( $content, $word, $color ) {
$replace = '<span style="background-color: ' . $color . ';">' . $word . '</span>'; // create replacement
$content = str_replace( $word, $replace, $content ); // replace content
return $content; // return highlighted data
}
function highlight_words( $content, $words, $colors ) {
$color_index = 0; // index of color (assuming it's an array)
// loop through words
foreach( $words as $word ) {
$content = highlight_word( $content, $word, $colors[$color_index] ); // highlight word
$color_index = ( $color_index + 1 ) % count( $colors ); // get next color index
}
return $content; // return highlighted data
}
// words to find
$words = array(
'normal',
'text'
);
// colors to use
$colors = array(
'#88ccff',
'#cc88ff'
);
// faking your results_text
$results_text = array(
array(
'ab' => 'AB #1',
'cd' => 'Some normal text with normal words isn\'t abnormal at all'
), array(
'ab' => 'AB #2',
'cd' => 'This is another text containing very normal content'
)
);
// loop through results (assuming $output1 is true)
foreach( $results_text as $result ) {
$result['cd'] = highlight_words( $result['cd'], $words, $colors );
echo '<fieldset><p>ab: ' . $result['ab'] . '<br />cd: ' . $result['cd'] . '</p></fieldset>';
}
Using Regular Expressions to replace content would do as well, though using str_replace() is a bit faster.
The functions accepts these arguments:
highlight_word( string, string, string );
highlight_words( string, array, array );
The above example results in:

Answer 2

By using str_ireplace instead of str_replace, the function will work case insensitive

Answer 3

I would not use the SQL method. As time goes on, and you have more and more highlighting rules, that will become unmanageable. Also trickier to handle the cases where you need to highlight foo differently to foobar, but one contains the other.
Separate your data handling from your formatting.