I am doing some PHP programming and have a question: How can I load a PHP function when the PHP script is first run, and only when it is first run?
thanks
You can use a Lock file
$lock = "run.lock" ;
if(!is_file($lock))
{
runOneTimeFuntion(); //
touch($lock);
}
Edit 1
One Time Function
runOneTimeFuntion ();
runOneTimeFuntion ();
runOneTimeFuntion ();
runOneTimeFuntion ();
runOneTimeFuntion ();
runOneTimeFuntion ();
runOneTimeFuntion ();
runOneTimeFuntion ();
function runOneTimeFuntion() {
if (counter () < 1) {
var_dump ( "test" );
}
}
function counter() {
static $count = 0;
return $count ++;
}
Output
string 'test' (length=4)
EACH time you start php script he starts as a new one, no matter how much times it was called befor.
And if you aware of re-declare functions, which is forbided in PHP, load functions from external fles useing:
<?php require_once(my_function_file.php); ?>
If you want scrpt remember if he was called befor, it's possible to do using some form of logging (data base\file) and cheacking it befor load... But I don't see any reason for this in case of function load...
Or use a plain boolean...
$bFirstRun = true;
if( $bFirstRun ) {
run_me();
$bFirstRun = false;
}
There is a PHP function called function_exists
You can define your own function within this function, and then you could see whether this exists or not.
if (!function_exists('myfunction')) {
function myfunction() {
// do something in the function
}
// call my function or do anything else that you like, from here on the function exists and thus this code will only run once.
}
Read more about function_exists here: http://www.php.net/function_exists
Related
I know I can use return to exit current script file, but what if we want to exit current script from inside a function?
For example, we define a exitScript() function that prints closing html tags and exits current script file, but if we use return it only exits from current function. Also exit() terminates whole script not only current file.
You can use Exceptions to do this, not particularly elegant, but this should do what your after, replace these methods.
public function fn1()
{
try {
$fn2 = $this->fn2();
}
catch ( Exception $e ) {
}
echo 'I want this to be displayed no matter what!';
}
public function fn4()
{
$random = rand(1, 100);
if ($random > 50)
{
return true;
}
else
{
// I want to exit/break the scirpt to continue running after
// the $fn2 = $this->fn2() call in the $this->fn1() function.
//exit();
throw new Exception();
echo "This shouldn't be displayed.";
}
}
You can return from an included file to the 'main file', skipping execution of the remaing part after the return.
So this will output: ABXend, skipping C
a.php
<?php
echo 'A';
include('b.php');
echo 'end';
?>
and b.php
<?php
echo 'B';
if(!x(6))return; //return here
echo 'C';
function x($num){
echo 'X';
if($num!==1)return false;
}
?>
I have one function call remove_certificate_packages($certificate_id, array_keys($package_id)) this will invoke the below function
function remove_certificate_packages($certificate_id, $package_id)
{
if (is_numeric($package_id)) // so this is list of package id:s
$package_id = array($package_id);
if (!$package_id) return true;
**notify_package_unlinked($certificate_id,array_keys($package_id));**//one more func call
return true;
}
in this function, I have one more function call "notify_package_unlinked" I need to pass the "$package_id". It will call the appropriate function but the problem is, in the "notify_package_unlinked" function the value is showing "Array". What is the problem? Could you please help
function notify_package_unlinked($certificate_id,$package_id)
{
$query="select id,filename,version from packages where id =$package_id";
$res = db_query($query);
$package= db_fetch_object($res);
$packid=$package->id;
$packname=$package->filename;
$packversion=$package->version;
print "$packid"; // here it is printing the value"Array"
}
I got my output using foreach loop .
foreach($package_id as $id){$pack=$id;}
I want a global array that I can access through controller functions, they can either add or delete any item with particular key. How do I do this? I have made my custom controller 'globals.php' and added it on autoload library.
<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
$notification_array = array();
$config['notification'] = $notification_array;
?>
following function on controller should add new item to my array
function add_data(){
array_unshift($this->config->item('notification'), "sample-data");
}
after add_data adds to the global array, whenever following function is called from client, it should give the updated array to the client.
function send_json()
{
header('content-type: application/json');
$target = $this->config->item('notification');
echo json_encode($target);
}
But my client always gets empty array. How can I make this happen? Please help.
Hi take advantage of OOP, like this
// put MY_Controller.php under core directory
class MY_Controller extends CI_Controller{
public $global_array = array('key1'=>'Value one','key2'=>'Value2'):
public function __construct() {
parent::__construct();
}
}
//page controller
class Page extends MY_Controller{
public function __construct() {
parent::__construct();
}
function send_json()
{
header('content-type: application/json');
$target = $this->global_array['key1'];
echo json_encode($target);
}
}
One solution I came up is to use session, its easy to use and its "fast" you need to do some benchmarking.
As I commented on both answers above/below there is no way you get same data in different controllers just because with each request everything is "reset", and to get to different controller you need to at least reload tha page. (note, even AJAX call makes new request)
Note that sessions are limited by size, you have a limit of 4kb (CodeIgniter stores session as Cookie) but wait, there is way around, store them in DB (to allow this go to config file and turn it on $config['sess_use_database'] = TRUE; + create table you will find more here)
Well lets get to the answer itself, as I understand you tried extending all your controllers if no do it and place some code in that core/MY_Controller.php file
as follows:
private function _initJSONSession() { //this function should be run in MY_Controller construct() after succesful login, $this->_initJSONSession(); //ignore return values
$json_session_data = $this->session->userdata('json');
if (empty($json_session_data )) {
$json_session_data['json'] = array(); //your default array if no session json exists,
//you can also have an array inside if you like
$this->session->set_userdata($ses_data);
return TRUE; //returns TRUE so you know session is created
}
return FALSE; //returns FALSE so you know session is already created
}
you also need these few functions they are self explainatory, all of them are public so you are free to use them in any controller that is extended by MY_Controller.php, like this
$this->_existsSession('json');
public function _existsSession( $session_name ) {
$ses_data = $this->session->userdata( $session_name );
if (empty( $ses_data )) return FALSE;
return TRUE;
}
public function _clearSession($session_name) {
$this->session->unset_userdata($session_name);
}
public function _loadSession($session_name) {
return (($this->_existsSession( $session_name )) ? $this->session->userdata($session_name) : FALSE );
}
the most interesting function is _loadSession(), its kind of self explainatory it took me a while to fully understand session itself, well in a few words you need to get (load) data that are in session already, do something with it ([CRUD] like add new data, or delete some) and than put back (REWRITE) all data in the same session.
Lets go to the example:
keep in mind that session is like 2d array (I work with 4+5d arrays myself)
$session['session_name'] = 'value';
$session['json'] = array('id' => '1', 'name' => 'asok', 'some_array' => array('array_in_array' => array()), 'etcetera' => '...');
so to write new (rewrite) thing in session you use
{
$session_name = 'json';
$session_data[$session_name] = $this->_loadSession($session_name);
//manipulate with array as you wish here, keep in mind that your variable is
$session_data[$session_name]['id'] = '2'; // also keep in mind all session variables are (string) type even (boolean) TRUE translates to '1'
//or create new index
$session_data[$session_name]['new_index'] = FALSE; // this retypes to (string) '0'
//now put session in place
$this->session->set_userdata($session_data);
}
if you like to use your own function add_data() you need to do this
well you need to pass some data to it first add_data($arr = array(), $data = ''){}
eg: array_unshift( $arr, $data );
{
//your default array that is set to _initJSONSession() is just pure empty array();
$session_name = 'json';
$session_data[$session_name] = $this->_loadSession( $session_name );
// to demonstrate I use native PHP function instead of yours add_data()
array_unshift( $session_data[$session_name], 'sample-data' );
$this->session->set_userdata( $session_data );
unset( $session_data );
}
That is it.
You can add a "global" array per controller.
At the top of your controller:
public $notification_array = array();
Then to access it inside of different functions you would use:
$this->notification_array;
So if you want to add items to it, you could do:
$this->notification_array['notification'] = "Something";
$this->notification_array['another'] = "Something Else";
I have a function that takes an input variable and outputs a template with the following call:
outputhtml($blue_widget);
outputhtml($red_widget);
outputhtml($green_widget);
And a simplified version of the function:
function outputhtml($type)
{
static $current;
if (isset($current))
{
$current++;
}
else
{
$current = 0;
}
//some logic here to determine template to output
return $widget_template;
}
Now here is my problem. If I call the function in a script three times or more, I want the output to be one way, but if I only call the function twice, then I have some html changes that need to be reflected in the templates that are returned.
So how can I modify this function to determine if there are only two calls for it. I can't go back after the fact and ask "hey function did you only run twice???"
Having trouble getting my head around how I tell a function that it is not going to be used after the second time and the necessary html modifications can be used. How would I go about accomplishing this?
function outputhtml($type)
{
static $current = 0;
$current++;
//some logic here to determine template to output
if ($current === 2) {
// called twice
}
if ($current > 2) {
// called more than twice
}
return $widget_template;
}
That would not be practical using a static $current inside the function; I would suggest using an object to maintain the state instead, like so:
class Something
{
private $current = 0;
function outputhtml($type)
{
// ... whatever
++$this->current;
return $template;
}
function didRunTwice()
{
return $this->current == 2;
}
}
The didRunTwice() method is asking "did you run twice?".
$s = new Something;
$tpl = $s->outputhtml(1);
// some other code here
$tpl2 = $s->outputhtml(2);
// some other code here
if ($s->didRunTwice()) {
// do stuff with $tpl and $tpl2
}
The only way you can find out if a function was only called twice is by putting the test at the end of your code; but perhaps by then the templates are no longer accessible? Can't tell much without seeing more code.
I'm gonna make this too complicated, just going to break it down to the main parts.
I have a form that changes the boolean of a variable when the form gets submitted, however it gets called by a function, the function has to change the variable.
class updates
{
var $yesno = false;
function updateBool()
{
$this->yesno = true;
}
}
So when the form gets submitted, it will call $up->updateBool() to change the boolean to true. When I do var_dump($up->yesno), it says false when it should be true. If I do this:
class updates
{
var $yesno = false;
function updateBool()
{
$this->yesno = true;
var_dump($this->yesno); // <-- outputs true
}
}
So how come I cannot get the variable to print out true in a seperate script?
EDIT:
$sql = "SELECT boolean
FROM config
WHERE boolean = 'true'";
$result = mysql_query($sql);
if(mysql_num_rows($result) > 0)
{
$up->updateBool();
}
else
{
header("Location: index.php?d=none");
}
This is part of the code where it gets called. I can confirm there are more than 1 record in the SQL statement.
So when the form gets submitted, it will call $up->updateBool() to change the boolean to true
You seem to be switching to a new page, where $up will be a new object. Objects do not persist across requests. PHP "loses its memory" when you call a new page, and all variables are started from scratch.
To persist values across page requests, you would need to use something like sessions.
class updates
{
public $yesno;
function __construct(){
$this->yesno = false;
}
function updateBool()
{
$this->yesno = true;
}
}