Processing multiple lines of data from a textarea; more efficient way? - php

Question

In my app I have a textarea, which my users are meant to enter data in the format:
Forename, Surname, YYYY-MM-DD, Company
Forename, Surname, YYYY-MM-DD, Company
on each line. My intention is to then loop through each row, exploding at the comma and trimming any white space.
I then need to pass the exploded array in to an associative array. I'm doing this manually at the moment, on the assumption that the user has entered the data in the correct order and format; which does work, but does rely on the user not messing things up.
What would you suggest as being a better way of doing this? I think the way I'm checking each index to see if it's empty or not seems rather clunky, as well as error prone.
Any suggestions or things to consider?
/************************************
* sample data from textarea:
* Name, Surname, 1980-02-22, Company
* Foo, Bar, 1970-05-12, Baz
************************************/
$data = preg_split('/\r\n|\n/', $_POST['data'],
-1, PREG_SPLIT_NO_EMPTY);
$item = array();
// loop through the data
foreach($data as $row) :
// trim and explode each line in to an array
$item[] = array_map('trim', explode(',', $row));
endforeach;
$k=0;
foreach($item as $user) :
$processed_data[$k]['first_name'] = !empty($user[0]) ? $user[0] : NULL;
$processed_data[$k]['last_name'] = !empty($user[1]) ? $user[1] : NULL;
if(!empty($user[2])) :
$dob = strtotime($user[2]);
if($dob) {
$processed_data[$k]['dob'] = $user[2];
} else {
$processed_data[$k]['dob'] = NULL;
}
else:
$processed_data[$k]['dob'] = NULL;
endif;
$processed_data[$k]['company'] = !empty($user[3]) ? $user[3] : NULL;
$k++;
endforeach;
// print_r($processed_data);

Answer 1

you are from the old school :)
Well, as you say above you expect the user to enter the data correctly in the text area. Well if your app is working currently in a robust system don't touch it, but otherwise you should consider to add different parameters in your post request (one for each filed you want to explode)...
you can do like this to solve the problem you have now:
// The algorithm below believe user send data correctly
// Forename, Surname, YYYY-MM-DD, Company
$names = array('first_name', 'last_name', 'dob', 'company_name');
$lines = explode("\n", $_POST['data']);
$result = array();
foreach ($lines as $ line)
{
$exploded_line = explode(",", $line);
$row = array();
foreach ($exploded_line as $key=>$item) { $row[$names[$key]]= trim($item); }
$result[]=$row;
}
// Now in result there is an array like this
// result[0][first_name]
// result[0][last_name]
// result[0][dob]
// result[0][company_name]
// result[1][first_name]
// [ ... ]

Answer 2

You can encapsulate the parsing and the validation into classes of it's own. Additionally you could do the same for the datastructure holding the tabular data.
class TableParser
{
private $string;
public function __construct($string)
{
$this->string = (string) $string;
}
public function parse()
{
$buffer = $this->string;
$rows = explode("\n", $buffer);
$rows = array_map('trim', $rows);
return $this->parseRows($rows);
}
private function parseRows(array $rows)
{
foreach($rows as &$row)
{
$row = $this->parseRow($row);
}
return $rows;
}
private function parseRow($row)
{
$keys = array('forename', 'surname', 'date', 'company');
$keyCount = count($keys)
$row = explode(',', $row, $keyCount);
if (count($row) != $keyCount)
{
throw new InvalidArgumentException('A row must have 4 columns.');
}
$row = array_map('trim', $row);
$row = array_combine($keys, $row);
return $row;
}
}
This parser is still quite rough. You can improve it over time, e.g. providing better error handling, given information which line failed and such. Such a component can then be easier integrated into your normal application flow as you can return that information back to the user so to enable her to make changes to the input.
Additionally you can put apart the validation into a second class and only do the exploding / trimming in the parser, but validation against count, specifying the array keys as well as validating the date format / value in the second class to keep things more apart.