基于重量的PHP重定向URL

Question

So I have an application that allows my client to enter in different url's and assign as many as he wants to a specific rotator as long as the weight always totals 100.

There is a link we give out to clients that when clicked on should fire a script that pulls the url and weight of that specific rotator and then redirect the end user to one of the url's assigned based on what weight it has.

I'm struggling because the url's and weights are dynamic and can change at anytime. I've seen a lot of examples but am still having an issue. If someone can please assist with this specific issue that would be fantastic.

Thanks.

Answer 1

Here is my fast implementation:

<?php

$urls = array(
    array('url' => 'http://google.com', 'weight' => 50),
    array('url' => 'http://microsoft.com', 'weight' => 13),
    array('url' => 'http://apple.com', 'weight' => 42),
);

$total_weight = 0;
foreach ($urls as $url) {
    $total_weight += $url['weight'];
}

$rand = mt_rand(1, $total_weight);
var_dump($rand);

$selected_url = '';
foreach ($urls as $url) {
    $rand -= $url['weight'];

    if ($rand <= 0) {
        $selected_url = $url['url'];
        break;
    }
}

var_dump($selected_url);

Another one, a little more ellegant:

<?php

$urls = array(
    array('url' => 'http://google.com', 'weight' => 50),
    array('url' => 'http://microsoft.com', 'weight' => 13),
    array('url' => 'http://apple.com', 'weight' => 42),
);

$probs = array();
foreach ($urls as $i => $url) {
    $probs = array_merge($probs, array_fill(1, $url['weight'], $i));
}

$rand = array_rand($probs);
var_dump($rand);
var_dump($urls[$probs[$rand]]['url']);