CODEWITHSUNDEEP
phpregex
Javacadabra
Javacadabra

Reputation: 5758

Regular Expression preg_match() for hreflang

I'm working on php script to output a number of hreflang tags based on the page the user is on. Currently I am using preg_match() to match the URL being requested again a specific pattern. If it matches output the relevant tags...

So I've got something like this:

<?php if (preg_match("/^\/en-gb\/company/i", $url)): ?>
    <link rel="alternate" href="https://www.mydomain1.com/en-gb/company/" hreflang="en-gb" />
    <link rel="alternate" href="https://www.mydomain1.com/company/" hreflang="en" />
    <link rel="alternate" href="https://www.mydomain1.com/company/" hreflang="x-default" />
<?php endif; ?>

when I visit the page www.mydomain1.com/en-gb/company it outputs the above tags. I also have another URL www.mydomain1.com/en-gb/company/stats. So I wrote another block for this URL:

   <?php if (preg_match("/^\/en-gb\/company\/stats/i", $url)): ?>
        <link rel="alternate" href="https://www.mydomain1.com/en-gb/company/stats" hreflang="en-gb" />
        <link rel="alternate" href="https://www.mydomain1.com/company/stats" hreflang="en" />
        <link rel="alternate" href="https://www.mydomain1.com/company/stats" hreflang="x-default" />
    <?php endif; ?>

However this page will output all of the hreflangtagsfrom the first if statement and never enters the second. I know my regular Expression is wrong but I can't pinpoint exactly where. I'd appreciate any help in order to resolve.

Upvotes: 1

Views: 335

Answers (2)

Wiktor Stribiżew
Wiktor Stribiżew

Reputation: 626952

You may restrict the first regex to avoid matching en-gb/company when followed with /stats using a negative lookahead:

preg_match("/^\/en-gb\/company(?!\/stats(?:\/|$))/i", $url)
                              ^^^^^^^^^^^^^^^^^^^

See the regex demo

The (?!\/stats(?:\/|$)) negative lookahead will fail all matches of /en-gb/company that are followed with /stats/ or /stats at the end of the input.

Note that in case you just want to check an entire path with the first regex, you may use Paladin76 approach by adding the $ end-of-string anchor, but I'd also add an optional / at the end:

preg_match("/^\/en-gb\/company\/?$/i", $url)
                              ^^^^

See this regex demo

Now, this pattern will only match inputs that are only equal to /en-gb/company or /en-gb/company/.

Upvotes: 1

Paladin
Paladin

Reputation: 1637

Try it with the end operator $ like this:

<?php if (preg_match("/^\/en-gb\/company\/$i", $url)): ?>

So, in your code, everytime, your url starts with en-gb/company it will hit your first code. Your second url also starts with en-gb/company, so you need to tell the matching, that it ends after company to go into your code.

Upvotes: 2

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