Is sanitize_title enough to generate post slugs?

4 comments

1. You are almost there. The function you need is sanitize_title_with_dashes( $title )

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2. sanitize_title() seems to be the only one you need.

   In wp-includes/default-filters.php line 211 you will find:

   add_filter( 'sanitize_title', 'sanitize_title_with_dashes', 10, 3);
   

   This means that calling sanitize_title() will first remove all the special characters, then apply the sanitize_title filter, thus calling sanitize_title_with_dashes()

   As @JHoffmann pointed out, simply calling sanitize_title_with_dashes() will not remove special characters.

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3. Well, there is already an answer, but I wanted to expand it a bit, so here are my findings:

   If we have a look in wp_insert_post() we see, the $post_name is sanitized using wp_sanitize_title() ( see wp-includes/post.php)

   In the function sanitize_title() we have a filter sanitize_title. This is interesting, since in the default filters sanitize_title_with_dashes() is hooked into this filter (see wp-includes/default-filters.php).

   <?php
   echo sanitize_title( 'Â+ÄÖßáèäç' ) // aaeoessaeaec
   ?>
   

   I tried sanitize_title() but it leaves %c2 %a0 in result.

   This sounds strange. It would be great to know the input value, but following wp_insert_post() sanitize_title() seems to be enough.

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4. In addition to websupporter’s great answer I found the below:

   Depending on your usage it will depend what you need.

   sanitize_title() as it says:

   accents are removed (accented characters are replaced with non-accented equivalents)

   …and sanitize_title_with_dashes says:

   Note that it does not replace special accented characters

   So, with this example string: Â+Ä Ö %%% ßá %20 oo %pp + -_^^#@!**()=[]|/'"<>?``~ èäç

   sanitize_title() result:

   aa-o-sa-%20-oo-pp-_-eac

   As you can see it has replaced accented characters with their non-accented equivalents and it has removed all other non-alphanumeric characters apart from the % which is followed by a number, but you will see it was removed when it was followed by a letter; perhaps this is because it perceives it as already encoded. This is enforced when you try inserting %c3 into your string, it doesn’t strip it as %c3 is a valid encoding sequence.

   sanitize_title_with_dashes result:

   %c3%a2%c3%a4-%c3%b6-%c3%9f%c3%a1-%20-oo-pp-_-%c3%a8%c3%a4%c3%a7

   So as you can see it hasn’t removed the accented characters, but encoded them.

   Now let’s look at a string with no accented characters to see how they both behave…

   Example String: %%% building %20 oo %pp + -_^^#@!**()=[]|/'"<>?``~'

   sanitize_title() result:

   building-%20-oo-pp-_

   sanitize_title_with_dashes result:

   building-%20-oo-pp-_

   So as you can see they are exactly the same. So it appears the only difference in them is that one encodes accented charters whilst the other replaces them.

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