PHP Form Validation Issue - Validate Large Set of Input Fields - php

Question

I have 20 "sets" of input fields in my HTML Form.
Here is a taster:
<input id="a1height" />
<input id="a1width" />
<input id="a1length" />
<input id="a1weight" />
<input id="a2height" />
<input id="a2width" />
<input id="a2length" />
<input id="a2weight" />
...and so on
Now, I need a way of:
a) storing all the values in one variable with pipes(|) between the height, width, length & weight and \n between each set
b) if one or more of the fields in a set is incomplete my variable $errors is set to true.
I'm at a little bit of a loss on how I can achieve this. Never really good with loops :'(
Can someone explain how to do this?
Many thanks!!

Answer 1

Here is a solution using an $errors array that stores all errors and an $all string that contains your desired output. To check, put var_dump( $all); at the end of the script.
$errors = array();
$all = '';
// Loop over the values 1 through 20
foreach( range( 1, 20) as $i)
{
// Create an array that stores all of the values for the current number
$values = array(
'a' . $i . 'height' => $_POST['a' . $i . 'height'],
'a' . $i . 'width' => $_POST['a' . $i . 'width'],
'a' . $i . 'length' => $_POST['a' . $i . 'length'],
'a' . $i . 'weight' => $_POST['a' . $i . 'weight']
);
// Make sure at least one submitted value is valid, if not, skip these entirely
if( count( array_filter( array_map( 'is_numeric', $values))))
{
// This basically checks if there's at least one numeric entry for the current $i
continue; // Skip
}
// Validate every value
foreach( $values as $key => $value)
{
if( empty( $value))
{
$errors[] = "Value $key is not set";
}
// You can add more validation in here, such as:
if( !is_numeric( $value))
{
$errors[] = "Value $key contains an invalid value '$value'";
}
}
// Join all of the values together to produce the desired output
$all .= implode( '|', $values) . "\n";
}
To nicely format the errors, try something like this:
// If there are errors
if( count( $errors) > 0)
{
echo '<div class="errors">';
// If there is only one, just print the only message
if( count( $errors) == 1)
{
echo $errors[0];
}
// Otherwise format them into an unordered list
else
{
echo '<ul>';
echo '<li>' . implode( '</li><li>', $errors) . '</li>';
echo '</ul>';
}
echo '</div>';
}

Answer 2

First should create NAME properties for your inputs, as these will be used in the _POST array to specify your values.
<input id="a1height" name="a1height" />
<input id="a1width" name="a1width" />
<input id="a1length" name="a1length" />
<input id="a1weight" name="a1weight" />
<input id="a2height" name="a2height" />
<input id="a2width" name="a2width" />
<input id="a2length" name="a2length" />
<input id="a2weight" name="a2weight" />
Then, after you submit, loop through the post array creating your pipe-joined varibles
$errors = false;
$string = "";
$current_prefix = '';
foreach($_POST as $key=>$posted_value){
if(trim($posted_value)==""){ //if the value is empty or just spaces
$errors = TRUE;
}
//find out if we need to add a new line
$number = preg_replace ('/[^\d]/', '', $key) //get the numbers of the name only
if ($current_prefix != $number){
$string .= "\n";
} else {
$string .= '|';
}
$string .= $posted_value;
}

Answer 3

Create an array to store your values.
Loop through your input fields, parsing the prefix (ie 'a1') from the field type (ie 'height')
Insert the values into the array like this:
$your_array['a1']['height'] = $_POST['a1height'];
Remember to validate and sanitize your input.

Answer 4

You can change your html so the posted fields come in a nicely formatted array:
<input name="a1[height]" />
<input name="a1[width]" />
<input name="a1[length]" />
<input name="a1[weight]" />
<input name="a2[height]" />
<input name="a2[width]" />
<input name="a2[length]" />
<input name="a2[weight]" />
That way you get an array that's easy to use. You could access $_POST['a1']['height'] or $_POST['a1']['length'] or $_POST['a2']['height'].