I am trying to use a require to place a table inside a define
define('ITEM1','text '.require('../../targetfile.php').' More text';
The idea is to pull in a table thats need on each define without having to copy and paste it each time.
I've tried various things but nothing has worked, I'm hoping you can, thanks in advance.
The targetfile.php would contain a large table
require() includes and evaluates the specified file. It stops execution on failure. On success it returns 1.
What you could do this this:
file1.php:
$myTable = '.....';
file2.php:
require('file1.php');
define('ITEM1','text '.$myTable.' More text');
define() can use variables because it creates the constant at run time.
Related
I am trying to include 2 php file in two separate <td> tags in the same table.
<td><?php include 'login.php';?> </td>
<td><?php include 'register.php';?> </td>
Both the php files include another php file for connecting to a database (eg. <?php include 'database.php';?>
Now, the problem is, the second file doesn't show up in the table. First file works.
Php files work independently. No problem with the code.
I removed the include in 1.php and everything worked fine - ie. both the files show up in table.
My conclusion is, it goes on including indefinitely. Now, how do I solve this?
regards
Ganesh Kumar
You can use include-once
The include_once statement includes and evaluates the specified file
during the execution of the script. This is a behavior similar to the
include statement, with the only difference being that if the code
from a file has already been included, it will not be included again.
As the name suggests, it will be included just once.
i.e.:
include_once('database.php');
include_once('login.php');
include_once('register.php');
You actually have several options, now that I think about it.
Require_once:
require_once('database.php')
This is the most accepted method for files such as this one that you describe, as it will hard-fail if the file cannot be included. For files that do program instantiation (I.e. database connection) this method is preferred.
Include_once:
include_once('login.php')
I've never found a reason to use this statement over require_once; however, that said, it doesn't mean there isn't one. If you have a file that does some instantiation of something related to your programme that isn't mission-critical, then you could suppose to use this directive over the other.
Define Include Constants:
This method requires a bit more explanation: instead of starting your included file (database.php in our example) off with the code for it, start it off in a manner similar to C/C99/C++.
<?php
if (!defined("INCLUDED_DATABASE"))
{
define("INCLUDED_DATABASE", true);
// add main body of file here
}
?>
This method basically accomplishes the same thing as the include_once and require_once, except that in no circumstances will it ever actually process the body twice in one request, even if you forget to use _once as a suffice to your include/require method. This goes back to the old days of C/C99/C++
where including a file twice would hard-fail the compiler, as duplicate definitions would take place.
Personally, I have always preferred the last option: it's the most strict. Yes, require_once and include_once when used diligently will have the same effect, but suppose someone (not even you necessarily) is modifying the application and accidentally does an include or require without the _once suffix, they will be having a bad day. This method prevents that.
That said, I still use a require_once when necessary, and a require if it can be included multiple times. (Files with that designation are not designed with the define construct.)
i am very new to php, i am used to writing .net, and i am finding the includes hard to understand and was hoping someone could help me understand how to correctly use an include once in a file, rather than inside each function..
take the following as an example
<?php
include 'test.php';
function test($a)
{
echo $value_from_test_php;
}
?>
the above code does not seem to work... however the below does
<?php
function test($a)
{
include 'test.php'
echo $value_from_test_php;
}
?>
i am having a hard time figuring out how to make an include work for all functions inside a file, rather then including it inside each function, any advice is greatly appreciated!
It's the scope of variable which is troubling you rather than includes, in PHP generally includes are used where there's a common page/markup to be included on each page, such as footer, header, etc
There are 4 types
include
include_once
require
require_once
The only difference is include will throw you an error if something goes wrong and will continue to execute the script where require will halt the further execution
You'll get everything here on includes - PHP Documentation
It all depends what is inside the file that you are include-ing! I would never, ever, suggest using include inside a function (or loop, or pretty much anything with brackets). Remember, the contents of the file being included are literally just "plopped in" place, right where the include statement is. So whatever scope (global, class, function, etc.) you're in when you include, is the scope that its contents will be declared in.
Put full class and function definitions in files, and include them at the top of the files where they are going to be used.
Your issue is not related to includes, but rather variable scope. By default a variable defined outside a function is not available within the function.
It's difficult to suggest the best solution without knowing exactly what it is you're trying to do, but the documentation (linked above) should get you started.
First example is not working because you use variable from global scope, if you want to use it then replace $value_from_test_php to $GLOBALS['my_var_name']
From what I understand using something like require_once will essentially copy and paste the code from one file into another, as if it was in the first file originally.
Meaning if I was to do something like this it would be valid
foo.php
<?php
require_once("bar.php");
?>
bar.php
<?php
print "Hello World!"
?>
running php foo.php will just output "Hello World!"
Now my question is, if I include require_once inside a method, will the file that is included be loaded when the script is loaded, or only when the method is called?.
And if it is only when the method is called, is there any benefit performance wise. Or would it be the same as if I had kept all the code into one big file.
I'm mainly asking as I've created an API file, which handles a large amount of calls, and I wan't to simplify the file. (I know I can do this just be creating separate classes, but I thought this would be good to know)
(Sorry if this has already been asked, I wasn't sure what to search for)
It will only include when the method is called, but have you looked at autoloading?
1) Only when the method is called.
2) I would imagine there's an intangible benefit to loading on the fly so the PHP interpreter doesn't have to parse extra code if it's not being used.
I usually use the include('bar.php'); i use it for when i use databvase information, i have a file called database.php with login info and when the file loads it calls it right up. I don't need to call up the function. It may not be the most effective and efficient but it works for me. You can also use include_once... include basically does what you want it to, it copies the code essencially..
As others have mentioned, yes, it's included just-in-time.
However, watch out for variable definitions (require()ing from a method will only allow access to local variables in that method's scope).
Keep in mind you can also return values (i.e. strings) from the included file, as well as buffer output with ob_start() etc.
I'm trying to include my AdSense code inside a variable like this:
$ad = include_once('../adsense/ad.php');
echo $ad;
In ad.php I'm doing this:
<?php
return '<script>...</script>';
?>
It's showing my AsSense ad but only once. After that, it's outputting 1. Am I missing something here?
You called include_once(), so the file will only be included one time. After that, it will return TRUE because the call succeeded, but no new content was included. Use plain include() instead if you need to use it multiple times.
$ad = include('../adsense/ad.php');
use include instead of include_once. That, or only call include_once once ;)
I think you may be better off using a function for this. You can get the same result, in a much more 'conventional' manner.
Using return in an include will work with include instead of include_once, as mentionned in other answers, but keep in mind include used in this manner makes for non-conventional code structures, harder to re-use, won`t show up in function list definition, among other inconveniances.
So I'm working on a PHP app and trying to make everything moduler. I have an index.php file that includes other php files. The first file included is settings.php which has my postgres credentials defined so they can be accessed elsewhere. The second file is connect.php that has a function you can pass sql to and it will return $result. The third file has functions that call the sql function and receive $result and parse it. In the third file, I can read the results of the $result however if I try if($result) it breaks and isset/empty have no effect.
Anyone have any ideas on a way to make this work, or is my structure just terrible?
Thanks so much!
Mike
let's say you have the following three files:
inc1.php
<?php
$foo = 'hello';
?>
inc2.php
<?php
echo $foo;
?>
main.php
include('inc1.php');
include('inc2.php');
it should echo "hello". however, passing variables around among files is a bad idea, and can lead to a lot of confusing, hard-to-follow code. If you need to pass variables around, use functions and/or objects so that you can at least see where they are coming from.
beyond that though, it's difficult to tell exactly what your problem is without seeing the code in question.
I would really try to switch to OOP. This makes things a lot of easier. If you just have to deal with classes, their methods and attributes you only have to include the classes and not this choas of functions. So I would recommend, give it a go ...