Creating a function that sanitizes the custom metabox excerpt

Question

I'm still getting to grips with functions and experimenting with different php functions.

I've created a function what I want to use in sync with my custom metabox excerpt. It will basically sanitize the data and make sure its 150 characters long and the first word starts with a capital letter.

My code is very loose at the minute as I'm testing the functionality out, But am kind of lost as to how I should go about this, Sorry for any simple mistakes.

the $test_excerpt was just to test it, but at the moment it outputs nothing.

Code is below.

<?php

//Function that trims any access spaces either side of the excerpt incase it fails the validation run

$text_excerpt = "test";

function vs_trim_excerpt($text_excerpt) {
    if(isset($text_excerpt)) {
    trim($text_excerpt);
    ucfirst($text_excerpt);
    wordwrap($text_excerpt, 150);
    return $test_excerpt();
    } 
}

vs_trim_excerpt();
?>

add_action('init', 'vs_trim_excerpt');

Answer 1

I am not sure this a WordPress question. It is really more just bad PHP but since that is a filter, in the spirit of fostering good will...

Your function is returning a variable-name function that doesn't exist, and none of your operations are saved at all. You are processing the string but you aren't keeping the changes. You need to assign the results to a variable. And, you aren't feeding the function any information to start with.

$text_excerpt = "test";
function vs_trim_excerpt($text_excerpt) {
    $text_excerpt = trim($text_excerpt);
    $text_excerpt = ucfirst($text_excerpt);
    $text_excerpt = wordwrap($text_excerpt, 150);
    return $text_excerpt;
} 
echo vs_trim_excerpt($text_excerpt);

That should work better.

Answer 2

You are missing some basic concepts of programming.

• variable scoping
• return values

Just because you define a variable in your first line it is not available in the scope of your function (it only exists in the global namespace). Also the functions you call actually return values. You need to assign the return values to a variable to use it. For example have a look at the PHP manual for trim():

Return Values: The trimmed string.

You always should read the manual pages for the functions you use, so you'll see if they return anything and in what form it is returned.

function vs_trim_excerpt($text_excerpt) {
    $text_excerpt = trim($text_excerpt);
    $text_excerpt = ucfirst($text_excerpt);
    $text_excerpt = wordwrap($text_excerpt, 150);
    return $text_excerpt;
} 

$text_excerpt = "test";
$new_excerpt = vs_trim_excerpt($text_excerpt);
var_dump($new_excerpt);