How to give meaningful names to functions in PHP? - php

Question

This might seem like a stupid and trivial question. I am having problem naming functions in PHP. I have two functions that retrieves all the information of a student given its id or name and email.
Since PHP doesn't have function overloading in the same sense as JAVA, I am having difficulty naming the functions.
Here is what I have done. These are the names that I have given them.
get_students_with_id($id) and get_students_with_name_and_email($name, $email)
But the parameters are gonna increase. I need a better and simple solution to name these functions or methods. BTW, they all belong to the same class. So what am I gonna do? Thanks in advance.

Answer 1

In PHP there doesn't exist the concept of method overriding like in JAVA, for example, but you can send default parameters, for example:
get_students($id, $name = null, $email = null)
This means that you don't need to call the function with the three parameters. You can do it by calling it just with one and it will assume it is the id. For example, if you want to have a function working for your example above, you could do something like:
function get_students($id, $name = null, $email) {
if (!empty($id)) {
// Get students by their ids
} else if (!empty($name) && !empty($email)) {
// Get students by their names and emails
}
}
And you can call the function above:
get_students(1); //Will retrieve studen with id 1
get_students(null, "Name", "email#email.com"); //Will retrieve students with name "Name" and email "email#email.com"

Answer 2

A search method could look something like this:
class Student {
public static $columns = ['id', 'name', 'email', 'password', /* ... */];
// Imagine that this method is called with the following array:
// ['name' => 'Joe', 'password' => 'Pa55w0rD']
public static function search(array $queries) {
// We will be appending WHERE clauses to this SQL query
$sql = 'SELECT * FROM students WHERE ';
// Get the column names
$parameters = array_keys($queries);
// Create a parameterized WHERE clause for each column
foreach ($parameters as & $param) {
if ( ! in_array($param, self::$columns)) {
throw "Invalid column";
}
$param = "{$param} = :{$param}";
}
// Squish parameterized WHERE clauses into one
// and append it to the SQL query
$sql .= implode(' AND ', $parameters);
// The query will now look something like this:
// SELECT * FROM students WHERE name = :name AND password = :password
// Prepare the SQL query
$stmt = DB::instance()->prepare($sql);
// Go over the queries and bind the values to the columns
foreach ($queries as $col => $val) {
$stmt->bindValue(":" . $col, $val);
// Internally the query will look something like this:
// SELECT * FROM students WHERE name = 'Joe' AND password = 'Pa55w0rD'
}
// Execute
$result = $stmt->execute();
// ...
}
}
To use the method you would do something like this:
$student = Student::search([
'name' => 'Joe',
'password' => 'Pa55w0rD',
]);
You would want to handle the data in a safer way (making sure the password is hashed, for instance), but the general idea is there.

Answer 3

Why not use get_students($id=0, $name='', $email='') and so on for your other parameters, then have the function do whatever is necessary based on the passed parameters?
If that gets to be too much, pass an array check for keys. So if array('id' => 1) is passed then if (array_key_exists('id', $input)) {...} would catch it and proceed with actual function work, but if other keys/values are passed then a subsequent appropriate elseif would catch it.
Update: I think a format like this might be able to handle most of your use cases, based on some of the comments I read in the question. Not sure what your DB is, so this was done with MySQL in mind.
function get_students($input) {
$where = array();
$allowed_columns = array('id', 'name', 'email');
foreach ($allowed_columns as $key) {
if (!array_key_exists($key, $input)) continue;
$where[] = "`$key` = '" . mysqli_escape_string($input[$key]) . "'";
}
if ($where) {
$query = 'SELECT ... FROM `...` WHERE ' . join(' AND ', $where);
// etc...
} else {
return false;
}
}

Answer 4

I would use a class instead of multiple functions
class Student
{
public static function byName($name)
{
// ...
}
public static function byId($id)
{
// ...
}
}
$student = Student::byName('joe');
This would allow it to be much cleaner and more extendible, as you can put common logic in protected static methods in the class.
If you want to do multiples you can do some chaining which is a little more complicated.
I've mocked up a quick ideone which you can reverse engineer:
http://ideone.com/duafK4