Building a small microframework with PHP (Part 2). Command line interface


In my last post we spoke about building a small microframework with PHP. The main goal of this kind of framework was to be able to map urls to plain PHP classes and become those classes easily testeable with PHPUnit. Now we’re going to take a step forward. Sometimes we need to execute the script from command line, for example if we need to use them in a crontab file. OK. We can use curl and perform a simple http call to the webserver. But it’s pretty straightforward to create a command line interface (CLI) for our microframework. Zend Framework and Symfony has a great console tools. I’ve used Zend_Console_Getopt in a project and is really easy to use and well documented. But now we’re going to build a command line interface from scratch.

We are going to reuse a lot of code from the earlier post, because of that we are going to encapsulate the code in a class (DRY).

We will use the getopt function from PHP’s function set.

$sortOptions = "";
$sortOptions .= "c:";
$sortOptions .= "f:";
$sortOptions .= "v::";
$sortOptions .= "h::";

$options = getopt($sortOptions);

Then we need to take the paramaters from $GLOBALS[‘argv’] superglobal according with the options. I use the following hack to prepare $GLOBALS[‘argv’]:

foreach( $options_array as $o => $a ) {
    while($k=array_search("-". $o. $a, $GLOBALS['argv'])) {
        if($k) {
            unset($GLOBALS['argv'][$k]);
        }
    }
    while($k=array_search("-" . $o, $GLOBALS['argv'])) {
        if($k) {
            unset($GLOBALS['argv'][$k]);
            unset($GLOBALS['argv'][$k+1]);
        }
    }
}
$GLOBALS['argv'] = array_merge($GLOBALS['argv']);

And now we get the params into $param_arr array.

$param_arr = array();
$lenght = count((array)$GLOBALS['argv']);
if ($lenght > 0) {
    for ($i = 1; $i < $lenght; $i++) {
        if (isset($GLOBALS['argv'][$i])) {
            list($paramName, $paramValue) = explode("=", $GLOBALS['argv'][$i], 2);
            $param_arr[$paramName] = $paramValue;
        }
    }
}

Now we can get className and functionName:

$className    = !array_key_exists('c', $options) ?: $options['c'];
$functionName = !array_key_exists('f', $options) ?: $options['f'];

We add a “usage” parameter:

if (array_key_exists('h', $options)) {
     $usage = <<<USAGE
Usage: cli [options] [-c] <class> [-f] <function> [args...]

Options:
-h Print this help
-v verbose mode
\n
USAGE;
    echo $usage;
    exit;
}

Now we can invoke the function with call_user_func_array

return call_user_func_array(array($className, $functionName), $this->realParams);

As you can see, instead of using $param_arr as parameters array, We need to create an extra $realParams array. The aim of this realParams arrays is to use call_user_func_array with named parameters. In getRealParams function we use reflection to see what are the real parameters of our function and use only those parameters form in the correct order instead. With this trick we will allow to the user to use the parameters in the his desired order, and without forcing to use the real order of our function.

    private function getRealParams($params)
    {
        $realParams = array();
        $class = new ReflectionClass(new $this->className);
        $reflect = $class->getMethod($this->functionName);

        foreach ($reflect->getParameters() as $i => $param) {
            $pname = $param->getName();
            if ($param->isPassedByReference()) {
                /// @todo shall we raise some warning?
            }
            if (array_key_exists($pname, $params)) {
                $realParams[] = $params[$pname];
            } else if ($param->isDefaultValueAvailable()) {
                $realParams[] = $param->getDefaultValue();
            } else {
                throw new Exception("{$this->className}::{$this->functionName}() param: missing param: {$pname}");
            }
        }
        return $realParams;
    }

And now we can use our microframework from the command line:

./cli -c 'Demo\Foo' -f hello
Hello

./cli -c Demo\\Foo -f getUsers
["Gonzalo","Peter"]

./cli -c Demo\\Foo -f helloName name=Gonzalo surname=Ayuso
Hello Gonzalo Ayuso

Full code on github

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About Gonzalo Ayuso

Web Architect specialized in Open Source technologies. PHP, Python, JQuery, Dojo, PostgreSQL, CouchDB and node.js but always learning.

Posted on August 29, 2011, in php, Technology and tagged , , . Bookmark the permalink. 2 Comments.

  1. Hey Gonzalo! Nice work. Have a look at line 10 of your second snippet – there is a wired github-thing :-)

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