Re: [PHP] new $foo->className(); Class name must be a valid object or a string

On May 3, 2008, at 4:46 PM, Jack Bates <[email protected]> wrote:

> I am trying to load PHP objects stored in a database, where the class
> name is stored in a column:
>
> $object = new $resultSet->getString(1);
>
> This fails for the same reason that the following fails:
>
> <?php
>
> class Foo
> {
>  public function className()
>  {
>    return 'Foo';
>  }
> }
>
> $foo = new Foo;
> $bar = new $foo->className();
>
> Fatal error: Class name must be a valid object or a string in test.php
> on line 12
>
> I guess this error is due to the confusion of parsing "()" as the
> argument list for the "className" function, or the "Foo"  
> constructor...
>
> I work around this error by using a temp variable:
>
> $tmp = $foo->className(); $bar = new $tmp;
>
> - however the above reads like hacky code : (
>
> When calling dynamically named functions, I generally use
> call_user_func() to avoid awkwardness with $object->$tmp($arg1, ...)
>
> In other words, I prefer:
>
> call_user_func(array($object, 'get'.$someName), $arg1, ...);
>
> - to:
>
> $tmp = 'get'.$someName; $object->$tmp($arg1, ...);
>
> However there does not appear to be an analog of call_user_func() for
> constructing new instances of dynamically named classes?
>
> If I recall correctly, there was also a way to work around calling
> dynamically named functions (e.g. $object->$tmp($arg1, ...);) using
> curly braces:
>
> $object->{'get'.$someName}($arg1, ...);
>
> - however I cannot recall the exact syntax.
>
> Can anyone confirm that there is a curly brace syntax for calling
> dynamically named functions? Could it be applied to instantiating
> dynamically named classes?
>
> Can anyone recommend a cleaner alternative to:
>
> $tmp = $foo->className(); $bar = new $tmp;
>
> Thanks and best wishes, Jack
>
Does...
<?php
  $bar = new $foo->className()();
?>
...work?

Otherwise, I'd just do...
<?php
  $className = $foo->className();
  $bar = new $className;
?>
...instead of $tmp.
>
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