在PHP中收集多个复选框的值（2以相同的形式提交？）

Question

I have two submits in the same form. One to filter the mySQL db and generate a list of checkboxes (works fine) and the other to display the values of the selected items using PHP (no go). Later on, I'll store these values to built a sql query. Please visit https://wintoweb.com/sandbox/question.php

I've tried everything you can imagine. Going nuts...

PHP function called from the [Show selected] button :

<?php      
function getNames() {
    //echo 'GOT IT !';              
    if(isset($_GET['choices[]'])){
        if(!empty($_GET['choices'])){
            foreach($_GET['choices'] as $selected){
                echo $selected."</br>";
            }
        }
    }
}
?>

Code for the [Show selected] button :

EXPECTED : the list of selected values below the ACTUAL OUTPUT : no list of selected values. The PHP function getNames() is never traversed.

Answer 1

I simplified your form.

<form name="dig" action="#" method="get">
<input type="search" name="l_name" value="Author's name (whole or part)" style="width:200px;" onfocus="this.value=''" onblur="(this.value=='')? this.value='Author's name (whole or part)':this.value;" />
<input type="submit" name="search" value="Search"> 
<input type="submit" name="display_all" value="Show selected">
<br /><br />
<table style="width:400px">
    <tr>
        <td width="100%"><input type="checkbox" name="choices[]" value="ABÉLARD, Pierre et HÉLOÏSE" onclick="">ABÉLARD, Pierre et HÉLOÏSE</td>  
    </tr>
    <tr>
        <td width="100%"><input type="checkbox" name="choices[]" value="ABOUT, Edmond" onclick="">ABOUT, Edmond</td>  
    </tr>
    <tr>
        <td width="100%"><input type="checkbox" name="choices[]" value="ABRANTÈS, Laure Junot" onclick="">ABRANTÈS, Laure Junot</td>  
    </tr>
</table>
</form>

<?php
error_reporting(E_ALL);
ini_set('display_errors', true);

if(isset($_GET['search'])){
    echo 'Search</br>';
} elseif(isset($_GET['display_all'])) {
    echo getNames();
}

function getNames() {
    $rets = '';
    if(isset($_GET['choices']) and !empty($_GET['choices'])){
      foreach($_GET['choices'] as $selected){
        $rets .= $selected.'</br>';
      }
    }
    return $rets;
}