如何在Phalcon中创建新的注射服务

Question

I'm trying to build a basic "JSON getter" for my Phalcon-based webapp, something like that:

function getJson($url, $assoc=false)
{
$curl = curl_init($url);
$json = curl_exec($curl);
curl_close($curl);
return json_decode($json, $assoc);
}

And of course I would like to make that stuff globally available, possibly as an injectable service. What could be the best way to do that? Should I implement a Phalcon\DI\Injectable? And then, how can I include the new class and feed it to the DI?

Thanks!

Answer 1

You could extend Phalcon\DI\Injectable but don't have to. A service can be represented by any class. The docs pretty well explain how to work with the dependency injection in general and specifically with Phalcon.

class JsonService 
{
    public function getJson($url, $assoc=false)
    {
        $curl = curl_init($url);
        $json = curl_exec($curl);
        curl_close($curl);
        return json_decode($json, $assoc);
    }
}

$di = new Phalcon\DI();

//Register a "db" service in the container
$di->setShared('db', function() {
    return new Connection(array(
        "host" => "localhost",
        "username" => "root",
        "password" => "secret",
        "dbname" => "invo"
    ));
});

//Register a "filter" service in the container
$di->setShared('filter', function() {
    return new Filter();
});

// Your json service...
$di->setShared('jsonService', function() {
    return new JsonService();
});

// Then later in the app...
DI::getDefault()->getShared('jsonService')->getJson(…);

// Or if the class where you're accessing the DI extends `Phalcon\DI\Injectable`
$this->di->getShared('jsonService')->getJson(…);

Just pay attention to get / set vs. getShared / setShared, there are services that may cause problems if created multiple times over and over again (not shared), e.g., take a lot of resources when instantiated. Setting service as shared ensures it's created only once and the instance is reused there after.