Re: [PHP] Variable functions within an object
Curt Zirzow wrote:
or for the oneline purists :)
${ ${$this->fname} = $this->fname }();
wow.. ${} is more powerful than i had originally though.
Thank you Curt,
With your suggestion, I finally re-wrote the example, and here it is:
function foo() {
echo "In foo()\n";
}
class a {
var $fname;
function a() {
$this->fname = 'foo'; // the name of the function
}
function execute() { // method to execute the named function
${${$this->fname}=$this->fname}();
}
}
$w = new a;
$w->execute();
?>
And this outputs:
X-Powered-By: PHP/4.1.2
Content-type: text/html
In foo()
Thank you again,
Sergio.
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Re: [PHP] Variable functions within an object
* Thus wrote Julio Sergio Santana:
>
> Curt Zirzow wrote:
>
> > $this->{$this->fname}();
> >
> > or (what it actually is doing.. )
> >
> > $func = $this->fname;
> > $this->$func();
> >
> >Curt
>
> The point here is that the named function is outside the object. That
> is, $this->foo() doesn't exist, so $this->{$this->fname}(), does not
> work either.
> But if you look at your suggested construct, I wonder why
> $this->{$this->fname}() is sintactically correct while
> {$this->fname}() is not (since we just striped out the prefix '$this->'
> which means that the function is inside the object).
Sorry, i did misread what actual function you were trying to
access, the problem is that {} isn't really the thing that expands
the variable its the special cases:
->{}
${}
{} by itself simply defines a code block.
> ...
>
> Clearly, $this->fname() means "call the object's method 'fname'", but
> {$this->fname}(), would mean "call the function whose name is
> '$this->fname'".
> I think, for the sake of orthogonallity, this feature should be added to
> the language.
One way to solve this without adding a feature like that would be:
${$this->fname} = $this->fname;
${$this->fname}();
or for the oneline purists :)
${ ${$this->fname} = $this->fname }();
wow.. ${} is more powerful than i had originally though.
Curt
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Re: [PHP] Variable functions within an object
Curt Zirzow wrote:
$this->{$this->fname}();
or (what it actually is doing.. )
$func = $this->fname;
$this->$func();
Curt
The point here is that the named function is outside the object. That
is, $this->foo() doesn't exist, so $this->{$this->fname}(), does not
work either.
But if you look at your suggested construct, I wonder why
$this->{$this->fname}() is sintactically correct while
{$this->fname}() is not (since we just striped out the prefix '$this->'
which means that the function is inside the object).
Look for instance at a similar case when dealing with variable variables
in arrays, this is what the online documentation says in this case:
"In order to use variable variables with arrays, you have to resolve an
ambiguity problem. That is, if you write $$a[1] then the parser needs to
know if you meant to use $a[1] as a variable, or if you wanted $$a as
the variable and then the [1] index from that variable. The syntax for
resolving this ambiguity is: ${$a[1]} for the first case and ${$a}[1]
for the second."
So, I think the case is similar here
Clearly, $this->fname() means "call the object's method 'fname'", but
{$this->fname}(), would mean "call the function whose name is
'$this->fname'".
I think, for the sake of orthogonallity, this feature should be added to
the language.
Thank you.
Sergio.
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Re: [PHP] Variable functions within an object
http://ca3.php.net/manual/en/function.call-user-func.php ?
Jason
On Thu, 29 Jul 2004 17:11:50 -0500, Julio Sergio Santana
<[EMAIL PROTECTED]> wrote:
> I need to record the names of functions, and then use them later.
> Recently I found the following example within the on-line documentation:
> function foo() {
> echo "In foo()\n";
> }
>
> $func = 'foo';
> $func();// This calls foo()
>
> ?>
>
> then I supposed that it was easy to extend this concept to objects and
> wrote the following case:
>
>
> function foo() {
> echo "In foo()\n";
> }
>
> class a {
>var $fname;
>function a() {
> $this->fname = 'foo'; // the name of the function
>}
>
>function execute() { // method to execute the named function
> $this->fname();
> // I also tried here
> // {$this->fname}();
> // ${this->fname}();
> // "$this->fname"();
> // but none of these worked
>}
> }
>
> $w = new a;
> $w->execute();
>
> ?>
>
> And this was the error I got:
>
> X-Powered-By: PHP/4.1.2
> Content-type: text/html
>
>
> Fatal error: Call to undefined function: fname() in - on
> line 14
>
> I know that this can be solved easily with an intermediate variable:
>
> $temp = $this->fname;
> $temp();
>
> but I wonder if there is a more direct method.
>
> --
> PHP General Mailing List (http://www.php.net/)
> To unsubscribe, visit: http://www.php.net/unsub.php
>
>
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Re: [PHP] Variable functions within an object
* Thus wrote Julio Sergio Santana:
>
> class a {
> var $fname;
> function a() {
> $this->fname = 'foo'; // the name of the function
> }
>
> function execute() { // method to execute the named function
> $this->fname();
> // I also tried here
> // {$this->fname}();
> // ${this->fname}();
> // "$this->fname"();
$this->{$this->fname}();
or (what it actually is doing.. )
$func = $this->fname;
$this->$func();
Curt
--
First, let me assure you that this is not one of those shady pyramid schemes
you've been hearing about. No, sir. Our model is the trapezoid!
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[PHP] Variable functions within an object
I need to record the names of functions, and then use them later.
Recently I found the following example within the on-line documentation:
\n";
}
$func = 'foo';
$func();// This calls foo()
?>
then I supposed that it was easy to extend this concept to objects and
wrote the following case:
function foo() {
echo "In foo()\n";
}
class a {
var $fname;
function a() {
$this->fname = 'foo'; // the name of the function
}
function execute() { // method to execute the named function
$this->fname();
// I also tried here
// {$this->fname}();
// ${this->fname}();
// "$this->fname"();
// but none of these worked
}
}
$w = new a;
$w->execute();
?>
And this was the error I got:
X-Powered-By: PHP/4.1.2
Content-type: text/html
Fatal error: Call to undefined function: fname() in - on
line 14
I know that this can be solved easily with an intermediate variable:
$temp = $this->fname;
$temp();
but I wonder if there is a more direct method.
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