file1:
<?php
function done() {
require_once '/home/vendor/autoload.php';
use Qiniu\Auth;
use Qiniu\Storage\UploadManager;
#omitted
}
?>
file2
<?php
require_once '/home/vendor/autoload.php';
use Qiniu\Auth;
use Qiniu\Storage\UploadManager;
function done() {
#omitted
}
?>
Why file1 can't work?
It should be rewritten as file2, why require and use can be written in the function body?
because from php doc
When a file is included, the code it contains inherits the variable scope of the line on which the include occurs. Any variables available at that line in the calling file will be available within the called file, from that point forward. However, all functions and classes defined in the included file have the global scope.
for use keyword the same rules apply
In Your case declaring isìnside the function limit the visibilty scope of the vars and code declaread in the included file
Related
Maybe I'm just tired or just am simply confused, but I'm having a strange issue dealing with some require_once() calls and ob_start().
Basic Structure:
Top of Main.php:
require_once 'config.php'; // includes variable $A = "bar", and Function "foo"
function getPage(){
ob_start();
include 'some_file.php';
$html = ob_get_clean();
echo $html;
die();
}
getPage();
some_file.php
require_once 'config.php'; // includes same config file
var_dump($A); // NULL
foo(); // runs, returns correct value
Config.php
$A = 'bar';
function foo(){
return "FOO";
}
So, what is wrong here? I'm including a file while buffering output. The required file config.php holds a variable and function. When including some_file.php during the buffer, the variable $A is apparently NOT set/accessible. The function foo CAN execute.
The documentation says:
When a file is included, the code it contains inherits the variable
scope of the line on which the include occurs. Any variables available
at that line in the calling file will be available within the called
file, from that point forward. However, all functions and classes
defined in the included file have the global scope.
Your provided code does not illustrate the problem that you're describing. When I run it as-is, it correctly shows that the variable is defined.
That being said, the thing to remember is that what looks like a global variable in an included file actually ends up in the scope of the function that's calling it. So if the first time require_once() is called is from a function, the $A variable is scoped to the function - and disappears when the function returns, just like any other variable defined inside the function.
If you absolutely must define a global variable inside an included file (are you sure? really?), make sure you only include that file from the global scope - not from within a function. If you need to access the variable from within a function, include the file outside the function, and then use the global keyword to access the variable from within the function.
In my code, I use a public load_snippet function of a class when I need to include HTML or PHP snippets. (I do this instead of a direct include_once because the directory structure varies depending on certain variables).
I had some issues with variable scopes, so I've narrowed down the problem to this: let's say I define a variable within my page:
$variable = 'Hello World!";
Then, I need load in a snippet:
$APP->load_snippet("slider");
The snippet renders perfectly, except that PHP gives an undefined variable error if I try to reference $variable in the slider code. If I directly include the php file, it works as expected, so I don't understand why I'm having this problem, since this is the load_snippet function:
public function load_snippet($snippet){
if(file_exists("app/".$this->APP_TYPE."/snippets/".$snippet.".php")){
include "app/".$this->APP_TYPE."/snippets/".$snippet.".php";
}
else{
include 'common/txt/404.txt';
}
}
Any help you can give me is much appreciated.
The file is being included within the context of the load_snippet() function, and therefore has only those variables which exist within that function. One way to modify this is to make your function accept two variables: the filename and an array of values.
public function load_snippet($snippet, $content) {
if (is_array($content)) extract($content);
if (file_exists("app/".$this->APP_TYPE."/snippets/".$snippet.".php")) {
include "app/".$this->APP_TYPE."/snippets/".$snippet.".php";
} else {
include 'common/txt/404.txt';
}
}
Then
$arr = array('variable' => 'Hello world!');
load_snippet('slider', $arr);
I think include inside a function makes no sense to me... I think that you should put in function
global $variable;
Note that include will put the code inside the function(include will be replaced by code) as i know..
The way you are doing it is an ugly one, but you can use global $variable inside the snipped to refer to the variable. However if you include the snipped inside a function or a method, you'll have to make the variables in that function/method global as well
If you need $variable inside of the App::load_snippet() method, it would probably be best to pass it in:
public function load_snippet($snippet, $var='Hello world'){
if(file_exists("app/".$this->APP_TYPE."/snippets/".$snippet.".php")){
include "app/".$this->APP_TYPE."/snippets/".$snippet.".php";
}else{
include 'common/txt/404.txt';
}
}
//do something with $var
}
You can set a default for when $variable hasn't been set. No globals, no out of scope variables.
Instead you can use the constants like define('VARIALABLE','value'). which will be available to you anywhere in your file
You are including inside a class. Which means that the included file has the same variable scope as the line of code which includes it has. TO fix this all you need to do is put
global $variable;
Above the include.
I am having an unexpected issue with scope. The include documentation (also applies to require_once) says the required file should have access to all variable at the line it was required.
For some reason I am not able to access a class instantiated with global scope inside a function that was required in.
Would anyone know why? I am obviously missing something.
I got it working through a reference to $GLOBALS[], but I still want to know why it is not working.
UPDATE:
The error I am getting is:
Fatal error: Call to a member function isAdmin() on a non-object in <path>.php on <line>
Code:
$newClass = new myClass();
require_once("path to my file");
----- inside required file -----
function someFunction() {
$newClass->someMethod(); // gives fatal error. (see above).
}
Functions define a new scope, so inside a function you cannot access variables in the global scope.
Variable Scope
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
About included files, the manual states:
When a file is included, the code it
contains inherits the variable scope
of the line on which the include
occurs.
So if you include something in a function, the included file's scope will be that of the function's.
UPDATE: Looking at your code example edited into the question, global $newClass; as the first line of the function should make it working.
$newClass = new myClass();
require_once("path to my file");
----- inside required file -----
function someFunction() {
global $newClass;
$newClass->someMethod();
}
Be aware though that using global can quickly make your code more difficult to maintain. Don't rely on the global scope, you can pass the object to the function as a parameter, or use a Singleton/Registry class (some tend to argue against the latter, but depending on the case it can be a cleaner solution).
The included code doesn't have a scope different than the code surrounding it. For example:
function a() {
echo $b;
}
This will fail even if echo $b is in an included file. If you replace the above with:
function a() {
include 'file.php';
}
... and file.php contains:
echo $b;
... then it's the same thing as if you wrote:
function a() {
echo $b;
}
Think of it this way: whenever you use include / require, the contents of the included file is going to replace the include / require statement, just as if you removed the statement and pasted the contents of the file in its place.
It doesn't do anything else as far as scope is concerned.
hello i want to know how to call a function defined in one php file from some other function defined in some other php page.
do like this, in the file where you need to call the function
require_once("file_having_function_that_you_need_to_call.php");
function_name($arguments); // this function is defined in 'file_having_function_that_you_need_to_call.php' file
First you need to include that file either using
require_once or require
or
include_once or include
if the function is not in class, you will call directly.
require("file.php");
echo getUserName("1")
otherwise you have to first create object and than call method
require("file.php");
$obj = new User();
echo $obj->getUserName("1");
Use include(), require(), etc. on the other PHP file, then just put the function name followed by its arguments in parentheses.
I have use
include ('base.php')
script in my other scripts ( more.php). Now base.php should receive one variable from more.php. How to pass a variable from more.php into base.php?
If you include a script file A into a script file B, then A has the same global variable scope as B has:
When a file is included, the code it contains inherits the variable scope of the line on which the include occurs. Any variables available at that line in the calling file will be available within the called file, from that point forward. However, all functions and classes defined in the included file have the global scope. — include manual page
So if you define a variable in A, then you have access to that variable in B:
// A.php
$varInA = 'foobar';
include 'B.php';
// B.php
echo $varInA;
Create a function within base.php, like so:
function setup($config) {
// Do something with config
}
and call it from more.php..
setup($somevar);
Or, you could try using classes and member variables and constructors.