Ok... so I have a game I'm developing and I'm running into a scope problem I think...
It starts in my js file fired by a click on the card the player wants to play:
It starts in my js file:
function playCard(playerId, card){
$.post("support_files/Blades_functions.php", {
method:'playCardFromHand',
playerID:playerId,
cardName:card
},function(data){
var attr = new Array();
attr = data.split("/");
alert(data);
$("#playerAttackPower").html(attr[0]);
$("#playerDefensePower").html(attr[1]);
$("#playerHealth").html(attr[2]);
$("#playerAttackMod").html(attr[3]);
$("#playerChargeCounters").html(attr[4]);
$("#playerSpecialAttackCounters").html(attr[5]);
});
}
Then into my php file
function playCardFromHand(){
$weapons = new WeaponCards(); // this is basically a class with variables(card objects) (my answer to php not having enums really)
$player = $theGame->gamePlayers[$_POST['playerID']]; // this is the variable ($theGame) that I declare in my main php file with all the markup on it. I'm including my functions file in my main file so the variable should be visible... I've tried using "global" keyword as well and that didn't do anything different...
$cardName = $_POST['cardName'];
$card = $weapons->$cardName;
$card->applyCard($player);
echo $player->getAttack()."/".$player->getDefense()."/".$player->getLife()."/".$player->getAttackMultiplier()."/".$player->getChargeCounters()."/".$player->getSpecAttackCounters();
}
So my problem is that the $player variable is null so nothing is displayed. Basically, as you can see in the callback on the js function, I'm just parsing out the string and updating the player's stats on the main php page. So is this a scope thing? Is there some way to make PHP persist that $theGame variable, which is an object itself, so that I can access/modify it in my functions file?
Any ideas would be most helpful... I've tried using the global keyword, as I said... tried making the variables in the $theGame object public, tried making them private and using getters and setters... I've had a separate problem with that actually, can't seem to get my functions to work on my objects in general, have just been making my variables public and accessing them directly instead of using the getters and setters. Anyway. Please help! I'm so frustrated!!! lol
Thanks,
Jon
Make sure that you declare your PHP variable as global, otherwise you have to get the POST variable inside of your function.
Related
/* I cant change this part (plugin core files) */
function test123(){
$secret = "hoho"; //i want to get this variable
do_action('custom'); //developer didnt pass any variable here
}
/* I cant change this part (plugin core files) */
add_action('custom',function() use ( $secret ) {
echo $secret; //didn't work
});
test123();
How to get $secret value? because the developer didnt pass any variable when using do_action
You can use like this:
function test123() {
$secret = 'hoho';
do_action( 'custom', $secret );
}
add_action('custom',function( $secret ) {
echo $secret;
});
test123();
Hope this works!
Your variable is out of scope
function test123(){
$secret = "hoho"; //i want to get this variable
do_action('custom'); //developer didnt pass any variable here
} //end of function scoope
add_action('custom',function() use ( $secret ) { //<-- $secret is undefined
echo $secret; //didn't work
});
There are several ways to fix this, but I cant really say how with so little context.
You could move add_action into the function
You could make $secret global etc.
modify the do action call to send it
make it a constant
make it global (keyword)
make it a property of class that maintains it's state (static etc.)
And so on, it depends how dynamic that value needs to be. Maybe that value is a static string, maybe it only exists in your function etc.
How many times you call that function may affect defining it inside, (add/remove action).
You can test this easly:
ini_set('display_errors', 1);
error_reporting(E_ALL);
add_action('custom',function() use ( $secret ) {
echo gettype($secret); //didn't work
});
Expected output
<br />
<b>Notice</b>: Undefined variable: secret in <b>...</b> on line <b>...</b><br />
NULL
UPDATE
I can't change test123()
I sort of figured that, which is why I only gave general solutions. In any case if it's just a plain old local variable within that function, there is no way to "get" its value outside of it short of editing the function in some way. This is a PHP thing (a language thing), not a WordPress thing. It has to do with how scope is handled within the function.
It may be possible to get that data some other way, that depends what it is. For example is it stored in the DB? You may be able to access that way etc... I can't say how to do that without knowing more about what it is.
It's not impossible to edit the original right. Obviously this is not ideal, but it's possible. Some tips are never edit the original. If it's part of a theme try to do it though a child theme. If it's plugin, or child theme doesn't work for it then you can duplicate it and change it's name.
I should mention depending how it's licensed this may be against that license.
You never want to edit the original because if you update the "plugin/theme" you may completely lose your changes. If it's in a copy you can comment around you changes like this:
/* START CUSTOM CODE */
And when you update the original "plugin/theme" you can easily find where your changes where (by searching for that comment text) and work them into the new version of the "plugin/theme". Which may be as simple as coping all the files but the one you changed (if nothing changed in it) etc.
As I said this isn't ideal, but it will work. It just depends how badly you want to implement it and how willing you are to maintain it.
Please see also
https://www.php.net/manual/en/language.variables.scope.php
within user-defined functions a local function scope is introduced. Any variable used inside a function is by default limited to the local function scope
I've been using procedural php for a long time but am still learning OOP. I was able to find a bit of code online that is in the form of a class and I am able to call a new instance of the class and use var_dump on a string to have it print JSON data to a web page. I can look at the results of the var_dump and see that it's returning exactly what I want. I'm then able to use json_decode on the same string to turn it into and associative array and then I can echo the values from within the class. The problem is, I need to use the array values in more code - it's great that I can confirm it by printing it to a web page but I need to use it... but I'm getting errors that state the array is undefined once I try to access it outside of the class.
I'm using this line to convert the data into an array:
$response_array = json_decode($body, true);
I've already confirmed that this works within the class by using this code to print some of the data:
echo $response_array['amount'];
and it works - I see it on the web page.
I've been using this code to create the new instance of the class:
$fdata = new FData();
$fdata->request($order_total, $cc_exp, $cc_number, $cc_name, $order_id, $customer_id);
(the function named 'request' is defined as a public function inside the class)
After that, I want to grab the $response_array so that I can store the returned data into a transactions table, i.e something like this:
$r = mysqli_query($dbc, "CALL add_transaction($order_id, $response_array['transaction_type'], $response_array['amount'], $response_array['exact_resp_code'], $response_array['exact_message'], $response_array['bank_resp_code'], $response_array['bank_message'], $response_array['sequence_no'], $response_array['retrieval_ref_no'], $response_array['transaction_tag'], $response_array['authorization_num'])");
but I keep getting an error saying that the array values are undefined.
Things I have already tried (and which failed) include:
Defining the variables as public inside the class, setting their value in the class, and then calling them outside the class...
public $amount = $response_array['amount'];
then using $amount in my procedure CALL --- I still get the error saying that $amount is undefined.
Using 'return', as in
return $response_array;
and still the error saying the values are undefined.
I tried embedding the entire rest of my code within the class, just copy/paste it in right after the json_decode... but for some reason it can't seem to then make the database calls and other things it needs to do.
I've been reading about __construct but I'm not sure if it applies or how to use it in this case...
I want to stress that I AM able to see the results I want when I use var_dump and echo from within the class.. I need to access the array created by json_decode OUTSIDE of the instance of the class.
Any advice would be greatly appreciated. Thanks.
Assuming your FData::request method ends with something like this...
$response_array = json_decode($body, true);
return $response_array;
and you call it like this...
$response_array = $fdata->request(...);
You should then be able to use $response_array in the calling scope.
Extra note; you should be using prepared statements with parameter binding instead of injecting values directly into your SQL statements.
I have a page named ChangeApprovalInfo.php - It has a function called Row_Rendered as follows;
function Row_Rendered() {
// To view properties of field class, use:
//var_dump($this-><FieldName>);
$RecordOwner = $this->RequestUser->CurrentValue;
echo $RecordOwner;
}
Echoing $RecordOwner gets me the data I will need for a sql query on another page....
I have another page called ChangeApprovalEdit.php - This page has
<?php include_once "ChangeApprovalinfo.php" ?>
at the top of the file.
ChangeApprovalEdit.php has a function where I need the $RecordOwner variable as defined in ChangedApprovalInfo.php
If I add "echo $RecordOwner" on the ChangeApprovalEdit.php page, I get an error saying it's an unknown variable. My understanding is that I need to "make it global" or some such business. I know very little about PHP and the pages I am editing are long and complex. (to me, at least)
What do I need to do? I know that the information I have provided might not be enough to answer the question. I don't know enough to even know exactly what I need to ask. If more information is needed, I will edit and follow up.
pastebin of the files
ChangeApprovalInfo.php = http://pastebin.com/bSRM1wwN
ChangeApprovalEdit.php = http://pastebin.com/AStG9pqb
EDIT:
Changing Row_Rendered to this seems to be more effective. I'm having trouble seeing WHERE I can later echo this variable... but I'm getting somewhere with this...
function Row_Rendered() {
// To view properties of field class, use:
//var_dump($this-><FieldName>);
$GLOBALS['RecordOwner'] = $this->RequestUser->CurrentValue;
}
Don't echo variables from functions, which just outputs them to the standard output. return them from the function so you can use the value elsewhere as well.
function Row_Rendered() {
$RecordOwner = $this->RequestUser->CurrentValue;
return $RecordOwner;
}
Then instead of
$obj->Row_Rendered();
use
echo $obj->Row_Rendered();
and if you want to use the value elsewhere, use
$value = $obj->Row_Rendered();
You can do a couple of things:
First, you can return $RecordOwner from the function, and store its value in a variable. This method is usually preferred.
function Row_Rendered() {
// To view properties of field class, use:
//var_dump($this-><FieldName>);
$RecordOwner = $this->RequestUser->CurrentValue;
echo $RecordOwner;
return $RecordOwner;
}
// Store it in a variable when calling the function.
$RecordOwner = Row_Rendered();
Or, you can make it global inside the function:
function Row_Rendered() {
// To view properties of field class, use:
//var_dump($this-><FieldName>);
$GLOBALS['RecordOwner'] = $this->RequestUser->CurrentValue;
echo $GLOBALS['RecordOwner'];
}
You can use the $GLOBALS superglobals array, like this:
function Row_Rendered() {
$GLOBALS['RecordOwner'] = $this->RequestUser->CurrentValue;
}
However, you should not do that. Instead, refactor your application so that the view in ChangeApprovalinfo.php just contains a function, which is then called with the appropriate parameters.
EDIT: Chaning Row_Rendered to this seems to be more effective. I'm having trouble seeing WHERE I can later echo this variable... but I'm getting somewhere with this...
function Row_Rendered() {
// To view properties of field class, use:
//var_dump($this-><FieldName>);
$GLOBALS['RecordOwner'] = $this->RequestUser->CurrentValue;
}
I feel compelled to write another answer to this update. Let me demonstrate the use of globals as seen from outside that function:
$obj->Row_Rendered();
$obj->foobar();
echo $GLOBALS['RecordOwner'];
Quick, what will be echoed and where does that value come from? Well, it depends on what $obj-foobar() does. Maybe it changes the global variable. Maybe it doesn't. Who knows if the variable has been set at all? How would you trace back what happened exactly without adding a debug line after every single function call?
And that's just three lines of code. Imagine that in an application of any complexity.
Now, the same thing if I return the value from Row_Rendered:
$owner = $obj->Row_Rendered();
$obj->foobar();
echo $owner;
If the Row_Rendered method is behaving as it should (returning the owner), this code is very predictable. If you do not follow this pattern, you'll have a hell of a time getting anything done when the application grows to any halfway complex size.
Set the variable as global from within the function
$my_global_var = "old value";
function doing_stuff(){
global $my_global_var; //this will use the global variable instead of creating a local one
$my_global_var = "new value";
}
echo $my_global_var;//returns "new value"
I'm using this code in a views field template (in this case views-view-field--all-members--uid.tpl.php):
<?php
$users_friends = flag_friend_get_friends($user->uid);
$users_friends_ids = array();
foreach ($users_friends as $id => $value) {
$users_friends_ids[] = $id;
}
?>
It basically gets the user ids of friends and puts them in an array so I can check if the field matches any of the user ids.
So my problem is that I don't want to have this within this template (for a few reasons), but if I don't I can't access the array. How can I make this array globally accessible?
Without knowing your "few reasons", I can't say if this is the answer for sure. My own reasons would probably be that I don't want the same code executing a bunch of times, and I'd rather not have the same exact code in multiple places.
I would then create a function with a static variable to hold the friends array.
function mymodule_get_friends_ids() {
// pull in the current global user variable
global $user;
// call up the static variable
static $users_friends_ids;
// return if this static var has already been set
if (is_array($users_friends_ids)) {
return $users_friends_ids;
}
// if we hit here, then this function has not been
// run yet for this page load.
// init array
$users_friends_ids = array();
// if user is anon, no need to go on
if (user_is_anonymous()) {
return $users_friends_ids;
}
// get friends array
$users_friends = flag_friend_get_friends($user->uid);
// build ids array
foreach ($users_friends as $id => $value) {
$users_friends_ids[] = $id;
}
return $users_friends_ids;
}
Now in your templates, you can call mymodule_get_friends_ids() in as many places as you want, and the working code below the first return will only get executed the first time it is called.
Coder1's advice is very good - it keeps you from populating your global variable namespace with a lot of junk. It's probably the most "elegant." It might not be the easiest to use if you are rather new to PHP (which I'm guessing might be the case if it's hard to get your head around returning arrays, but that's ok).
However, if this is really a priority, you probably don't care about having one extra global variable.
I suppose I may be stating the obvious here - but you can, at pretty much any point in execution (provided the information you need has already been generated - e.g., the $user variable has been populated), do this:
$GLOBALS['users_friends_ids'] = /* your code goes here */
Then in your template, you access this by ...
$friendsArray = $GLOBALS['users_friends_ids'];
Or you can simply use the construct
global $user_friends_ids;
when you want to initialize the variable, or access it inside a function or class (which is the case for your template files - they are called inside functions, so you need to globalize or use the $GLOBALS array, which is "automagically" all of the variables active in the global namespace).
The most "logical" place to do this would be inside a module using one of the many hooks available, to execute this code only once. hook_init() might do it for you, if the user object is already loaded at this point (not sure, you'll have to test). But you might not want to figure out making Drupal modules (it's not that difficult).
If you are doing this inside a template (and though it's not good practice, many Drupal site owners with a beginning knowledge of PHP put everything in templates), you'll want to know which template code is being executed when. Node template code tends to be executed before page template code - which is logical, since otherwise the variables for node content in the page template wouldn't be populated.
If you have listings of nodes, they'll be calling this code multiple times, so you'll end up doing something similar to what Coder1 is describing. If you don't want to create your own small module, you could put the function declaration he's written in your theme's template.php file, since it's called only once. You don't want to put function declarations in the tpl.php files, since they are sometimes called more than once (and you aren't allowed to declare functions more than once).
If you have a hard time understanding the function and the return, you can always do something like this in your code (which is very, very inelegant - but it's better to have inelegant code that you do understand, than elegant code that's you don't).
if(!isset($GLOBALS['users_friends_ids'])) {
$GLOBALS['users_friends_ids'] = /* your code here */
}
I have instantiated a class in my index.php file. But then I use jQuery Ajax to call some PHP files, but they can't use my object that I created in the index.php file.
How can I make it work? Because I don´t want to create new objects, because the one I created holds all the property values I want to use.
Use the session to save the object for the next page load.
// Create a new object
$object = new stdClass();
$object->value = 'something';
$object->other_value = 'something else';
// Start the session
session_start();
// Save the object in the user's session
$_SESSION['object'] = $object;
Then in the next page that loads from AJAX
// Start the session saved from last time
session_start();
// Get the object out
$object = $_SESSION['object'];
// Prints "something"
print $object->value;
By using the PHP sessions you can save data across many pages for a certain user. For example, maybe each user has a shopping cart object that contains a list of items they want to buy. Since you are storing that data in THAT USERS session only - each user can have their own shopping cart object that is saved on each page!
Another option if you dont want to use sessions is to serialize your object and send it through a $_POST value in your AJAX call. Not the most elegant way to do it, but a good alternative if you don't want to use sessions.
See Object Serialization in the documentation for more informations.
mm, you should store in session, $_SESSION["someobj"] = $myobj;, and ensure that when you call the Ajax PHP file this includes the class necessary files which defines the class of $myobj and any contained object in it.
Could you be more specific? I can try.
This is how I create an object then assign it to a session variable:
include(whateverfilethathastheclassorincludeit.php)
$theObject = new TheObjectClass();
//do something with the object or not
$_SESSION['myobject'] = $theObject;
This is how I access the object's members in my Ajax call PHP file:
include(whateverfilethathastheclassorincludeit.php)
$theObject = $_SESSION['myobject'];
//do something with the object
If you don't want to move your object that is in your index.php, have your ajax make a request to index.php but add some extra parameters (post/get) that let your index.php know to process it as an ajax request and not return your normal web page html output.
You have not provided code, but what I guess is that you need to make your instantiated object global for other scripts to see it, example:
$myobject = new myobject();
Now I want to use this object elsewhere, probably under some function or class, or any place where it is not getting recognized, so I will make this global with the global keyword and it will be available there as well:
global $myobject;
Once you have the object, you can put it into the session and then utilize it in the Ajax script file.
As others have suggested, $_SESSION is the standard way to do it, in fact, that was one of the reasons, that sessions where invented to solve. Other options, i.e. serializing the object rely on the client side to hold the object and then return it untampered. Depending on the data in the object, it is not a good solution, as a) the object may include information that should not be available on the client side for security reasons and b) you will have to verify the object after receiving it.
That said, and if you still want to use the object on the client side, then JSON is an option for serializing object data, see JSON functions in PHP.
Based on most of the answers here, referring to storing the object in $_SESSION, is it more efficient to store only the individual properties that need to be accessed in AJAX as opposed to the whole object, or does it not matter?
E.g.
$_SESSION['object'] = $object;
vs
$_SESSION['property1'] = $object->property1;
$_SESSION['property2'] = $object->property2;
I know the OP is asking about accessing the entire object, but I guess my question pertains to if it's just a matter of only accessing certain properties of an object, and not needing to access methods of a class to alter the object once it's in AJAX.