[SOLVED] Overloading with arays?

[OldWolf]

Hey folks,

 

I hope this isn't too obscure of a question, but below is the __set bit from my class.  Following that is how I'm attempting to make use of the object.  Is there any reason why "key" with a value of "value" wouldn't be set into $data['menu_blocks'][0]["key"]["value"]?  $data has been created, and the object ($tpl) is actually an object.

 

Thanks!

 

public function __set($key, $value)
{
	$this->data[$key] = $value;
}

 

$tpl->menu_blocks[] = array('key' => 'value');

[OldWolf]

And yes, I do realize array is spelled with two r's... lol.  Darn typos 

[aschk]

Err i think you're mistaking what the $key=>$value syntax means.

I would expect $data['menu_blocks'][0]["key"] to hold the string "value"...

 

i.e.

$data['menu_blocks'][0]["key"] = "value"

[OldWolf]

Yes, that's what I meant... I have no idea why I wrote $data['menu_blocks'][0]["key"]["value"]... I was very tired.  I meant to say $data['menu_blocks'][0]["key"] = "value"

 

The original problem still exists, I just mistyped my explanation.  Is there any reason my code wouldn't store that value?  Because it's not for some reason.  :/

[corbin]

That would be like trying to do:

 

$array1 = array();
$array2 = array();
$array1[$array2[]] = array('key',' value');

 

 

Would you expect that to work?

[OldWolf]

Ohhhh, so what it's trying to do is $this->data[menu_blocks[0]]['key'] instead of $this->data[menu_blocks][0]['key']. 

 

Well duh, shoot I feel stupid. :X

 

Thanks for clearing that up, dumb mistake on my part.

 

To be clear, what my goal there was was to allow something like this:

$tpl->menu_blocks[] = array('key' => 'value');

$tpl->menu_blocks[] = array('key2' => 'value2');

$tpl->menu_blocks[] = array('key3' => 'value3');

 

So that the $tpl->data['menu_blocks'] would end up being an array of those values.  Is there any way to go about doing that without setting them into an array on the same line (I'd like to be able to add menu blocks as I go basically), or without accessing the actual $tpl->data array (so it's changeable later)?

[corbin]

I don't think it's possible to do it like that .

 

void __set ( string $name , mixed $value )

 

 

So if name is a string, and you're assigning it like

 

$var[$name] = $value

 

Then you're setting it like:

 

$var['name[]'] = 'value';

 

(assuming $name is name[] and $value is value)

 

 

Three things could be done here.

-PHP could know that it can't be handled correctly and never call __set() (which is what I think happens)

-The literal key of name[] could be assigned value

-It could just error

 

 

 

So, there are a few ways around this I guess.

 

You could check the variable name in __set (terribly ineffecient), or you could make a method for setting the values of menu_blocks.  For example:

 

class RandomClass {
    private $data = array();
    
    public function __set($k, $v) {
        $this->data[$k] = $v;
    }

    public function AddToMenuBlocks($vals) {
        if(!isset($this->data['menu_blocks'])) $this->data['menu_blocks'] = array();
        $this->data['menu_blocks'][] = $vals;
    }

    public function __get($key) {
        if(isset($this->data[$key])) return $this->data[$key];
    }

}

$rc = new RandomClass;

$rc->AddToMenuBlocks(array('1', '2'));
$rc->AddToMenuBlocks(array('3', '4'));

print_r($rc->menu_blocks);

/*
Output:

Array
(
    [0] => Array
        (
            [0] => 1
            [1] => 2
        )

    [1] => Array
        (
            [0] => 3
            [1] => 4
        )

)
*/

[keeB]

What you're looking for is this.

 

public function __set($key, $value)
{
	$this->data[$key][] = $value;
}

 

Or am I missing sometthing?

[corbin]

Yeah I thought of that too, but what if he wants to set variables not like that?

 

When I said, "You could check the variable name in __set (terribly ineffecient)" I was meaning that he could do that, but I was thinking it would be better to handle just the menu_blocks that way.  Guess if that's the only variable that he's setting, what ever works.

[OldWolf]

Yeah I thought of that too, but what if he wants to set variables not like that?

 

This is correct.  The point of the class is to be the translation between my code and whatever template system I happen to be using.  The idea is that no matter which system I use or switch to later, all I'll have to do is change the class a bit, instead of running through all the code messing with things.  For the most part, the template will need individual variables set, like "username" where no array will be involved passed the data array.

 

I thought of making a separate method for the menu block, but the problem I run into there is that I'll then need to create a separate method for each item that needs an array to be built as I go.  I'm thinking I might find a decent compromise in creating a method called something like build, which would basically be the suggested $this->data[$key][] = $value; method, so that I have both options.  Not efficient, but at least portable.

 

Thanks for your help,

James

[keeB]

It sounds like you need to go back to the drawing board to understand the desires behavior of your template engine. If you have the existing (which work) cases in mind, and take this one in to consideration, you may come out with something much more simple and efficient.

 

At least, it makes much more sense going back to the beginning than to try to impose a bandage in to a system that isn't conducive to it. We generally call those 'hacks' for good reason.

[OldWolf]

You may be right, but I'm rather tired of working on this piece.  I'm also running short on ideas.  :/

[aschk]

I have fashioned a solution for you, it involves returning a reference to the interal object that you're setting. It also relies on the fact that you set the variable to a particular type to begin with :

 

<?php

class my_class {

private $data;

public function __construct(){
	$this->data = array();
}

public function __set($key, $val){
	$this->data[$key] = $val;
}

public function &__get($key){
	return $this->data[$key];
}

}


$test = new my_class();
$test->menu_blocks = array();
$test->menu_blocks[] = array("key"=>"val");

print_r($test);

?>

 

This will achieve what you're after, but bear in mind you need to set the format of the offending item to begin with, i.e. $test->menu_blocks = array();

[corbin]

Ahhh, so because of the reference return from __get, it will return the var as a ref then you can add to it....  Nice!

[OldWolf]

Thank you for the idea!  Just today I had a great realization that seems to be working perfectly:

 

public function __set($key, $value)
{
	$this->data = array_merge_recursive($this->data, array($key => $value));
}

 

This achieves what I want with the following example code:

$m['lang'] = 'Navigate!';
$m['type'] = 'header';
$m['order'] = -100;
$tpl->menu_blocks = array($m);

$m['lang'] = 'Navigate2!';
$m['type'] = 'header';
$m['order'] = 5;
$tpl->menu_blocks = array($m);

This puts the blocks into a numerical array under $this->data['menu_blocks'] = array(0 => 'menu block array', 1 => 'menu block array2');

 

It also lets me set single value entries by just doing the $tpl->key = 'value'; which will be set into $this->data['key'] = 'value';

 

Thanks for everyone's help!

[corbin]

Hrmmm that's pretty clever.

 

 

I would go with aschk's way personally though for 2 reasons:

 

1.  It allows you to set stuff not as arrays (well overlapping arrays, i.e. you can set the same value twice).

 

2.  It is probably faster.

[OldWolf]

I suppose my method does have the disadvantage of not being able to overwrite a set value, so I'll have to unset and set values each time.  That could pose a problem down the road.

 

If I do use his approach, I'd probably want to universally use a similar system with all of my objects (so I end up coding in a uniform way).  Other than having to be very careful what the returned value gets set into (so that I'm not accidentally making changes to the object value on what I wanted to be a temporary value), could you foresee any problems with this?

 

Thanks again!

[aschk]

As nice as using magic methods is, i believe it's probably better to provide a comphrehensive suite of functionality. As such I have provided a sample class that you may use if you wish.

 

<?php

class Template implements ArrayAccess {

private $data;

public function __construct(){
	$this->data = array();
}

public function set($key, $val, $overwrite = false){
	if($this->offsetExists($key) && !$overwrite){
		throw new Exception("Offset '{$key}' exists.",1);
		return;
	}
	$this->data[$key] = $val;
}

public function get($key){
	if($this->offsetExists($key)){
		return $this->offsetGet($key);
	}
	return null;
}

public function merge($key, $val, $idx=0){
	if(!is_array($val)){
		if($idx > 0){
			$tmp = $this->get($key);
			$tmp[$idx]= $val;
			$this->set($key,$tmp,true);	
			return;
		}
		$this->merge($key, array($idx=>$val));
		//throw new Exception("Value '{$val}' is not a valid array.");
		return;
	}
	$this->set($key, array_merge($this->get($key), $val), true);
}

public function __set($key, $val){
	$this->set($key, $val, false);
}

public function __get($key){
	return $this->get($key);
}

public function offsetExists($offset){
	if(array_key_exists($offset, $this->data)){
		return true;
	}
	return false;
}

public function offsetGet($offset){
	return $this->data[$offset];
}

public function offsetSet($offset, $value){
	if($this->offsetExists($offset)){
		throw new Exception("Offset '{$offset}' exists. Use the merge() method.");
		return;
	}
	$this->data[$offset] = $value;
}

public function offsetUnset($offset){
	unset($this->data[$offset]);
}

}
?>

 

To use it you can do the following:

<?php
// Create class.
$test = new Template();

// See what's in it now.
$test['menu_blocks'] = "aeraerg";
print_r($test);

// Set menu_blocks to an array (we must overwrite it because it exists already otherwise we'll get an exception.
$test->set('menu_blocks',array("zero"=>"intial value"), true);

// Merge more values into menu_blocks
$test->merge('menu_blocks',"value");
$test->merge('menu_blocks',"value",5);
$test->merge('menu_blocks',array("zero"=>"overwritten value","one"=>"1st value"));

// Have a look at the resulting class.
print_r($test);
?>

[OldWolf]

Thanks!  I'm not sure I'm going to use exactly that class, but I will work with my class based on it.

 

OldWolf