Automatically add links to strings of keywords - php

Question

In my article, I want to automatically add links to keywords.
My keywords array:
$keywords = [
0=>['id'=>1,'slug'=>'getName','url'=>'https://example.com/1'],
1=>['id'=>2,'slug'=>'testName','url'=>'https://example.com/2'],
2=>['id'=>3,'slug'=>'ign','url'=>'https://example.com/3'],
];
This is my code:
private function keywords_replace(string $string, array $key_array)
{
$array_first = $key_array;
$array_last = [];
foreach ($array_first as $key=>$value)
{
$array_last[$key] = [$key, $value['slug'], '<a target="_blank" href="' . $value['url'] . '" title="' . $value['slug'] . '">' . $value['slug'] . '</a>'];
}
$count = count($array_last);
for ($i=0; $i<$count;$i++)
{
for ($j=$count-1;$j>$i;$j--)
{
if (strlen($array_last[$j][1]) > strlen($array_last[$j-1][1]))
{
$tmp = $array_last[$j];
$array_last[$j] = $array_last[$j-1];
$array_last[$j-1] = $tmp;
}
}
}
$keys = $array_last;
foreach ($keys as $key)
{
$string = str_ireplace($key[1],$key[0],$string);
}
foreach ($keys as $key)
{
$string = str_ireplace($key[0],$key[2],$string);
}
return $string;
}
result:
$str = "<p>Just a test: getName testName";
echo $this->keywords_replace($str,$keywords);
like this:Just a test: getName testName
very import: If the string has no spaces, it will not match.Because I will use other languages, sentences will not have spaces like English. Like Wordpress key words auto link
I think my code is not perfect，Is there a better algorithm to implement this function? Thanks!

Answer 1

You can use array_reduce and preg_replace to replace all occurrences of the slug words in your string with the corresponding url values:
$keywords = [
0=>['id'=>1,'slug'=>'getName','url'=>'https://www.getname.com'],
1=>['id'=>2,'slug'=>'testName','url'=>'https://www.testname.com'],
2=>['id'=>3,'slug'=>'ign','url'=>'https://www.ign.com'],
];
$str = "<p>Just a test: getName testName";
echo array_reduce($keywords, function ($c, $v) { return preg_replace('/\\b(' . $v['slug'] . ')\\b/', $v['url'], $c); }, $str);
Output:
<p>Just a test: https://www.getname.com https://www.testname.com
Demo on 3v4l.org
Update
To change the text into links, you need to use this:
echo array_reduce($keywords,
function ($c, $v) {
return preg_replace('/\\b(' . $v['slug'] . ')\\b/',
'$1', $c);
},
$str);
Output:
<p>Just a test: getName testName
Updated demo
Update 2
Because some of the links that are being substituted include words that are also values of slug, it's necessary to do all the replacements at once using the array format of strtr. We build an array of patterns and replacements using array_column, array_combine and array_map, then pass that to strtr:
$reps = array_combine(array_column($keywords, 'slug'),
array_map(function ($k) { return '' . $k['slug'] . ''; }, $keywords
));
$newstr = strtr($str, $reps);
New demo

Answer 2

First you need to change structure of array to key/value using loop that result stored in $newKeywords. Then using preg_replace_callback() select every word in string and check that it exist in key of array. If exist, wrap it in anchor tag.
$newKeywords = [];
foreach ($keywords as $keyword)
$newKeywords[$keyword['slug']] = $keyword['url'];
$newStr = preg_replace_callback("/(\w+)/", function($m) use($newKeywords){
return isset($newKeywords[$m[0]]) ? "<a href='{$newKeywords[$m[0]]}'>{$m[0]}</a>" : $m[0];
}, $str);
Output:
<p>Just a test: <a href='https://www.getname.com'>getName</a> <a href='https://www.testname.com'>testName</a></p>
Check result in demo

Answer 3

My answer uses preg_replace as does Nick's above.
It relies on the patterns and replacements being equally sized arrays, with corresponding patterns and replacements.
Word boundaries need to be respected, which I doubt you can do with a simple string replacement.
<?php
$keywords = [
0=>['id'=>1,'slug'=>'foo','url'=>'https://www.example.com/foo'],
1=>['id'=>2,'slug'=>'bar','url'=>'https://www.example.com/bar'],
2=>['id'=>3,'slug'=>'baz','url'=>'https://www.example.com/baz'],
];
foreach ($keywords as $item)
{
$patterns[] = '#\b(' . $item['slug'] . ')\b#i';
$replacements[] = '$1';
}
$html = "<p>I once knew a barbed man named <i>Foo</i>, he often visited the bar.</p>";
print preg_replace($patterns, $replacements, $html);
Output:
<p>I once knew a barbed man named <i>Foo</i>, he often visited the bar.</p>

Answer 4

This is my answer: thanks for #Nick
$content = array_reduce($keywords , function ($c, $v) {
return preg_replace('/(>[^<>]*?)(' . $v['slug'] . ')([^<>]*?<)/', '$1$2$3', $c);
}, $str);