index_ajax.php

<?php
session_start();
require_once 'functions/functions.php';
require_once 'functions/database.php';

function search_get($data) {
    $logged_in_user = user\get_logged_in_user();
    $user_id = NULL;
    if ($logged_in_user) $user_id = $logged_in_user['id'];
    $trips = database\get_trips_near_on(
        $data['route'],
        $data['departure'],
        $user_id);
    if ($trips == NULL) $trips = array();
    $trips_found = array("trips" => $trips);
    functions\json_respond('OK', 'Searched!', $trips_found);
}

function request_post($data) {
    $logged_in_user = user\get_logged_in_user();
    if (!$logged_in_user)
        return functions\json_respond('ERROR', 'Login Required!');

    $request_data = array(
        "user_id" => $logged_in_user['id'],
        "trip_id" => $data['trip_id'],
        "message" => $data['message']);

    if (database\request_ride($request_data))
        return functions\json_respond('OK', 'Request Sent!');
    else
        return functions\json_respond('ERROR', 'Unable to request ride');
}

if ($_GET) {
    search_get(json_decode($_GET['data'], true));
} elseif ($_POST) {
    request_post(json_decode($_POST['data'], true));
}