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PHP - Global Variables. Yay Or Nay? Alternatives Maybe?
If I want to load some user information from the database into an object/array and share it throughout my application, what's the best approach for this? Here is what I thought of doing:
- I can call a function (e.g user_info() ) that will return the user information whenever I need it , but It'll have to run a DB query each time I call it. - Load user information once from the DB, assign it into a global array/object, then call that object whenever I need it. A lot of people recommended against using global variables, but I think performance wise it's better than running a query each time. Are there any better alternatives than the above approaches? Similar TutorialsI use $db object to handle database function like $db->get_row for example. Is there any way that I don't need to put into every function global $db or do I actually need to repeat in every function global $db? Code: [Select] function example(){ global $db //Do I need to repeat this in each function? } $errors=0; //NEW USER NAME HAS BEEN SUBMITTED, CHECK IT OUT AND THEN ADD IF OKAY $newuser=$_REQUEST['newuser']; function TryAgain(){ global $errors; $errors++; echo '<br/><br/>Please try again <a href="index.php?locate=admin&sub=add_admin">here</a>'; echo "<br/>errors=[$errors]"; } echo "<br/>Trying to add user: $newuser<br/><br/>"; if ($newuser){ }else{ // field was left blank, report this to user and give them option to try again echo '<br/>Field was left empty, you must pick a username.';TryAgain(); } if (strlen($newuser)<5){echo 'Username should be at least 5 characters.';TryAgain();} if (!$errors){echo "continue to SQL [errors=$errors]";} what is wrong with this code? For some reason if I increment $errors with $errors++ within the function it doesn't increment outside the function's scope. even though I declare it as a global at the start of the function. I know I'm doing something stupid here but can somebody please tell me what it is? Thanks I need the following three variables to be available globally, that is to every page. (An common header.html uses them at every page). Please teach me how to initialize them. (inside the header.html maybe?) 'U_M_CODE' => append_sid("{$phpbb_root_path}faq.$phpEx", 'mode=bbcode'), 'U_M_TERMS' => append_sid("{$phpbb_root_path}ucp.$phpEx", 'mode=terms'), 'U_M_PRV' => append_sid("{$phpbb_root_path}ucp.$phpEx", 'mode=privacy'), Thank you. Hi there, I am a highly concerned about ever using global variables (as many guides I have seen on security issues with PHP say you should avoid them, kind of understand why though to be fair), but I was wanting to really understand custom based session handlers in PHP and this first one he http://uk.php.net/manual/en/function.session-set-save-handler.php on the example: 'Example #1 session_set_save_handler() example' uses them. Now would it be better to take the global variable in function: ''open()' and then return the variable $sess_save_path then pass it up to the next function that may need it perhaps? I just don't want to use globals if I can avoid it, been working out a system that work use for some old solution we use and it uses globals and it really bugs the living life out of me, why people are so lazy they can't avoid them at all costs grrr. Any advice generally speaking is of great appreciation, Jeremy. Hi, In all my classes, I need to declare globals for everything else, from site variables even to objects (other classes). I obviously don't want to as globals are horrible and I need to have functions clean without globals. I have included a list of all the global vars in the construct and it still doesn't work. Example: start.php <?php $vars = array(some values); $some = more; $variables = foo; $helper = new Helper(); $home = new Home(); This is a little bit simplistic, but for some reason, the variables just don't want to go in the main class without a global. Functions will not run if they require any of these variables. Hello I've have read that global variables should not be used. so if i have 2 .php files: index.php - main content php file sitefunctions.php - php functions site file on my index.php page i have the following (an example of my problem): <?php displayError($errorID); ?> and in the sitefunctions.php file i have the following (an example of my problem): <?php function displayError($errorID) { if($errorID == 1) { echo "Password Failure"; } else { echo "Other Failure"; } } ?> now that works but since when first accesing that page the $errorID is not set then i get an error. How can i achieve this without first setting a blank $errorID global variable? Thanks Hello, my global variable is getting whacked (defined null or being undefined) after a function call. I'm not sure if it's happening when leaving the function that assigns it or when the form is "posted", or something else. Code: [Select] <? //global variables $globalVarString = ""; //function definitions function displayResults() { global $globalVarString; if ($globalVarString == "") {displayForm("please enter your search string again");} else {displayForm("you typed: $globalVarString");} } function getResults($searchInput) { global $globalVarString; $globalVarString = $searchInput; //give status ?> <html><head><title>Search</title></head><body> <form action="<?=$_SERVER['PHP_SELF']?>" method="post"> Thanks for entering your data (<? echo "$globalVarString" ?>).<br><br>Please press the submit button to process your data    <input type="Submit" value="Submit" name="processQuery"> </form></body></html> <? } function displayForm($message) { //prompt for input ?> <html><head><title>Search</title></head><body> <form action=" <? $_SERVER['PHP_SELF'] ?>" method="post"> <h3>Please enter your search <input type="text" name="searchString">    <script type="text/javascript">document.forms[0].searchString.focus();</script> <input type="Submit" value="Submit Query" name="searchQuery"></h3> </form> <? if (!$message == ""){echo "<br>    <h4>" . $message . "</h4><br>";} ?> </body></html> <? } //main() if(array_key_exists('searchQuery', $_POST)) {getResults($_POST['searchString']);} elseif (array_key_exists('processQuery', $_POST)) {displayResults();} else {displayForm("");} ?> This topic has been moved to Third Party PHP Scripts. http://www.phpfreaks.com/forums/index.php?topic=350034.0 I created had created a website between me and a couple friends. On the website I made an Ajax\Javascript\Php Instant Messenger. It works fine for something small. Each user has a contact list and currently I am saving each individual conversation between each user into an Sql table { senderId, RecieverId, Message } and reading it back. Now I know its no problem for something small but obviously it leaves security risks and sends too many requests to the server. Any of you guys have any alternative Idea's for this messenger? I don't necessary need to save the conversations, I'm simply using that method to send and receive them. I have a buddy who does his messenger through J.S sockets but I would like to keep to php if possible. Any comments or suggestions would be much appreciated. Uploaded with ImageShack.us Sometimes I have various data which I wish to be available to all scripts. Typically, they are constants which are related, and using PHP's constants makes them difficult to group.
As such, my solution has been to create a single global variable such as $GLOBALS['myGlobalVariable'], and dump them all in it.
Are there better ways to implement this? For instance, using a singleton? Please provide rational why one solution is better than the other.
Thank you
<?php
class mySinglton {
private static $instance = NULL;
private function __construct() {}
private function __clone(){}
public static function mySinglton($values=null)
{
if (!self::$instance)
{
self::$instance = new stdClass();
foreach ($values as $key=>$value) {
self::$instance->$key=$value;
}
}
return self::$instance;
}
}
class someClass
{
public $a=1,$b=2,$c=3;
}
$globals=array(
'foo'=>'bar',
'daysOfWeek'=>array('Sunday','Monday','Tuesday','Wednesday','Thursday','Friday','Saturday'),
'someClass'=>new someClass
);
$GLOBALS['myGlobalVariable']=$globals;
mySinglton::mySinglton($globals);
testIt();
function testIt()
{
echo('<pre>'.print_r($GLOBALS['myGlobalVariable'],1).'</pre>');
echo('<pre>'.print_r($GLOBALS['myGlobalVariable']['foo'],1).'</pre>');
echo('<pre>'.print_r(mySinglton::mySinglton(),1).'</pre>');
echo('<pre>'.print_r(mySinglton::mySinglton()->foo,1).'</pre>');
}
?>
I'm wondering if there's any alternatives to redirecting. For example, after the registration process, I have a fully loaded User object with all of the information I need to load the user's profile (the place that logging in/registering takes you to). I can call the profile action of the user controller and pass in the User object and it will display just fine. The problem is that since the URL is still pointing to the register action if the user refreshes their page its going to try sending the previous form again. Alternatively I could redirect to the profile and have it load that way, but then I'm fetching data from the database seemingly unnecessarily since I had all of the data I needed already fetched prior to redirecting. Is there anyway that I could do the first process but change the url and forget the previous form data so that if they refresh its just refreshing the profile and not resending the previous request? Thanks in advance for any help. I am using API-Platform, Doctrine, and Symfony with entities that utilize class type inheritance to extend an abstract entity. I've been running into one issue after another primarily related to the serialization process (serialization groups, parent annotations not propagated to the child, etc), and while I am sure user error on my part is part of the culprit, it appears that API-Platform and potentially Symfony and Doctrine don't fully support entity inheritance. My reason for thinking so is the incredibly sparse amount of documentation on the subject and remarks on quite a few github issues posts and other blogs how it is "bad practice". For instance, say I have Mouse, Cat, and Dog which all extend AbstractAnimal, and each has a bunch of common properties such as birthday, weight, etc, and methods such as eats(), sleeps(), etc. Sorry in advance for using hypothetical entities but I don't think doing so distracts. I like how inheritance allows me to keep all common properties in a single table, but can let that go. More importantly, the subset mouse, cat, and dog table shares an ID from the animal table allowing me to associate all animals to some other table (i.e. many-to-one to person whether they are their pet or many-to-many to country whether they are native to a country), and to retrieve a list of animals and filter by some property or type as needed without a bunch of unions. To me, this sounds like inheritance, but if the products I am using don't support it very well, it doesn't matter. First question. Is entity inheritance considered bad practice? And even if not, is it common for frameworks to limit their level of support for them? If so, what can I do about it? Maybe favor composition over inheritance? Okay, great, I now have a single animal table which makes all my SQL concerns issues go away and I am pretty confident that my serialization issues will also go away. All I need to do is inject each animal with some "thing" to make them a mouse, cat, or dog. But what do I call this thing? I've struggled with this topic for a while and asked the same question regarding how to deal with BarCharts, PieCharts, GaugeCharts, LineCharts, etc all being charts but all acting slightly differently, and never really came to any conclusion. For a non-hypothetical scenario, I have BacnetGateway and ModbusGateway which extend AbstractGateway. Okay, this one is easy and I change to just having a Gateway and inject either BacnetProtocol or ModbusProtocol. For another non-hypothetical scenario, I have PhysicalPoint which represents some real environmental parameter, VirtualPoint which represents combining one or more PhysicalPoints or VirtualPoints, and TransformedPoint (feel free to provide a better name) which represents performing some time function such as integrating over a given time. Currently, they all extend AbstractPoint, but if I was trying to do so with composition, I could inject PointType but don't think doing so makes sense. For my hypothetical scenario, do I make a DNA interface and inject an Animal with DogDNA to get a dog? I really need to get my head around this once and for all. Thanks Hello again, So, after messing around with gettext, and having found the solution to my previous post (https://forums.phpfreaks.com/topic/310383-gettext-for-multilangual-not-working-for-me/), I've come to the conclusion that I need to use something else than gettext in order to make my site multilingual.
Problem I have with gettext is that I absolutely need to have my desired languages (i.e. fr_FR, nl_NL, etc) installed on my server's system (in my case, a NAS for now). I can see which locales I have on my server with 'locale -a'. I am in no way able to install new locales on my NAS. It's too limited... too much locked down. So, I'm looking for an alternative to gettext. Any suggestions for me perhaps ? Thanks for any advice. Pat
Now i use a very complex normal for, how i can use a foreach? I am trying to do the following. Except I know that 'return' is not the right method to use, as it stops the script, so what ends up happening is only one row is returned, instead of the three that are there. With return, the data is being passed without being immediately printed, and I end up with the data (but not all of it, because the script stops) in correct place in the page. If I replace return () with echo(), it works fine, in terms of returning the correct data. However, with the way things are setup, if I use echo, the results print at the head of my page. I am using function CreateSideMenu to establish the values for content, and then another function, later on the index.php page, actually creates the page. So what I need is to have something, similar to return (), that passes the information on, but does not immediately print it. Do I make sense? see code below: function CreateSideMenu () { // open CreateSideMenu function include ('/Users/max/Sites/rdbase-llc/hidden/defin/kinnect01.php'); $query = "SELECT content_element_title, content_element_short_text FROM content_main"; $result = mysql_query ($query, $dbc); while ($row = mysql_fetch_array ($result, MYSQL_ASSOC)) { return ("<p>" . $row[content_element_title] . "</h2>\n<p>" . $row[content_element_short_text] . "</p>"); } Thanks ahead of time. This topic has been moved to Ajax Help. http://www.phpfreaks.com/forums/index.php?topic=326703.0 This question may sound very lame... ... But I have never able to know how to define a variable that I can use in different functions in a same file. There is no class structure just a PHP file with some functions. Is it possible to use some type of variable that can be share by all functions and that variable should not be a session variable . Something like: <?php $my_global_var; function A() { // use $my_global_var here } function B() { // use $my_global_var here and should retain the last value } ?> Something like in VB6.... Thanks hello, ok if i set a Global on index.php (wwwroot/admin/index.php) it works Code: [Select] $page1='hello from page1 on index'; global $page1; echo $page1; i can echo $page1 on other pages like (wwwroot/admin/pages/home.php) and it will echo out "hello from page1 on index". GREAT but if i write a Global on (wwwroot/admin/pages/home.php) it does not work. i also can not echo it out on any other page Code: [Select] $page2='hello from page2 on home'; global $page2; echo $page2; why is this ??? I have some variables that I have set with the global command but they don't seem to be working correctly. It's probably my order of operation but not sure. Here's the stripped down version of whats going on: locator() //functions function geoip() global $zip, $city, $areacode, $metrocode, $state, $country, $latitude, $longitude; function locator() geoip() use globals from geoip pass to- ad_display() function ad_display() does some work stat_tracking() function stat_tracking() access global $zip, $city, $areacode, $metrocode, $state, $country, $latitude, $longitude; The problem is once I call stat_tracking() and try to access the global variables, they are all empty. Just to clarify the chain of events is: page loads, calls locator(), locator() calls function geoip() fine then passes work to ad_display(), ad_display() calls stat_tracking(), stat_tracking() now tries to access the globals I made but all variables are blank if I echo them. Any ideas? |
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