Question about 'return' inside snippet

Hi everyone,

I have a question about ’return’ usage inside snippets.

function functionOne() {
return ’A String ’;
}
functionOne(); //Shouldn’t output anything to the page
echo functionOne(); //Should output ’A String ’
return ’String Two’; //Shouldn’t output anything to the page

The result of the above code is:
A String String Two

The return that is not inside the function is acting like an echo()...

In a standard php script the result from the same code is:
A String

Output from snippet in MODx should be always returned at the end of the snippet..

eg:



echo also works in snippets, but the output won’t necessarily come to the place where you expect it to be on the page. So get your snippet output in a variable and return it at the end, don’t use echo. See also this.

This is only valid for Evolution though, AFAIK in Revolution you can use echo just fine in a snippet.

What comes to your code above, these lines print that output from your snippet:

echo functionOne(); //Should output ’A String ’
return ’String Two’; //Shouldn’t output anything to the page

Your code acts just as expected in MODx.

MODx outputs whatever is returned from the snippet, as well as anything that’s echo’d in the snippet.



The first line doesn’t output anything.
The second line echos the return value of the function so it puts out "A String"
The third line, with a return outside a function, returns "String Two" from the snippet which MODx then outputs to the screen.

Hope this helps you understand how MODx works.

Thanks for the replies guys.

So when using ’return’ inside snippets, is this true?

1.) A ’return’ inside a function, and that function is called, nothing is echo’d/printed to the page
2.) A ’return’ outside a function works exactly the same as echo or print, since MODx echo’s whatever is returned from a snippet



Thanks,

Mark

You probably know this, but number 2 is only true if the return is executed.

return (’hello’);

return(’goodbye’);


Will result in only ’hello’ being output.

Return in a snippet ends the snippet immediately (as does exit() or die() ) and nothing more is executed within the snippet.

Look closely at Doze’s example above it provides an excellent way of doing things in a snippet. If you use $output and then contcatenate your desired output to it with .= and then just have one return($output) statement in your snippet (never using echo or print), it will make your life *way* easier in the long run.

If your snippet is at all complicated, you’ll also want to look into using $modx->setPlaceholder() and putting placeholders in a template chunk.

That way you can set your snippet’s output to various placeholders anywhere in the snippet with no concerns about order or formatting. Then you just "return" the contents of the template chunk.


and MODx does the rest for you by replacing the placeholders in the template with the values you’ve set before the page is sent to the browser.

In a MODx snippet whatever is returned by the snippet is echoed, but in a standard PHP script return echoes nothing, it just returns a value

The following lines of code at the end of a snippet do the exact same thing, i.e. print foo onto the page (the only exception being the return stops the parser executing the snippet)

$foo = $modx->getPlaceholder(’bar’);
echo $foo; //This line outputs to the screen
print $foo; //This line outputs to the screen
return $foo; //This line outputs to the screen and stops script execution. In a standard PHP script: return never outputs to the screen on its own

Why does MODx automatically echo everything ’returned’ from a snippet?

Why does MODx automatically echo everything ’returned’ from a snippet?

Because the standard function of a snippet is to insert something into your html document. Because snippets are such a powerful feature of modx people keep finding ways of utilizing them beyond that basic function. As long as you’re aware of it it’s easy to overcome this.

And you always have the option of returning nothing if you have a snippet that you don’t want to produce output in the browser.

I think that it is great that modx echos everything it returns. I find this to be very easy to work with. I just think of snippets being functions and will always use the return to generate the output, simple. The cool thing is that you can use either echo or return (although I recommend return).

Just curious, I have never run into a situation where this would be a problem, how is this causing a problem in your script?

Hi guys,

Thanks for the replies.

"Just curious, I have never run into a situation where this would be a problem, how is this causing a problem in your script?"

I never ran into any problems with this, I’m just trying to get a better understanding of how returns are handled by the MODx parser.

Basically, all of my posts were asking the same questions:

(a)Why does a return outside a function in a MODx snippet automaticallly echo the output to the screen?
(b)If the MODx parser automatically echos returned output from a snipppet, why does a call to the function that contains a return not echo the results as well?
(c)Why is there a disparity between the way a ’return’ is handled by a standard PHP script and a MODx snippet?

The cool thing is that you can use either echo or return (although I recommend return).

I know a return looks a bit fancier than the oul faithfull echo, but with the exception of script execution (return false;), a return outside a function in a MODx snippet does the exact same thing as an echo... (it echoes the output to the screen)