Running JavaScript in PHP file
I made a simple login using JavaScript, but record the username in a PHP session.It's a simple web chat, so I want when the chat page is loaded the user to be forced to pick an username, but after that I want to store that info ina a PHP session and if the page is reloaded for some reason to do a check if $_SESSION['UserName'] is empty and if it's not to stop the script from executing again.I put my login JS in <body onload..> and the code looks like this:
<body onload = "showUser(), showChat(), <?php if ($_SESSION['UserName']==""){
{
Login();
}?>">
I'm just learning now, so I gues I have some newb mistakes, like I'm almost sure that I'm not calling the Login() function right (it's JS function), but that's my strating point.Could anyone explain to me, how should I do the check properly and add the JS function in my PHP code?
P.S And I don't know if this really matter but if I remove the PHP code and leave liek this:
<body onload = "showUser(), showChat(),Login()">
My script is executed properly and I get everything that should be shown when the page is loaded, but when I add the PHP script and try to load the page I get blank page.I really wonder what's开发者_如何学C the reason for this too?
You cant call a js function from php. instead we have to print the js function as string in php so it will be executed as js along the html.
<body onload = "showUser(); showChat(); <?php if ($_SESSION['UserName']==""){ echo 'Login();'; }?>">
To Write efficient php code:
<body onload = "showUser(); showChat(); <?php echo (($_SESSION['UserName']=='')?'Login();':''); ?>">
You get blank page because of fatal error. which is occurred due to the javascript function you called in php (ERROR: Undefined function login() ).
You must echo the text Login(); from PHP - PHP does not execute Javascript, but you can use it to control which Javascript functions are called.
<body onload="showUser(), showChat(), <?php
if(isset(!$_SESSION['UserName']) || $_SESSION['UserName'] == ""){
echo 'Login();';
}?>">
You are effectively using PHP to create two different body tags - one for logged in users, and one for others.
Side note: it's good practice to check that an array item exists before attempting to access it: isset($_SESSION['UserName']) || $_SESSION['UserName'] checks first if $_SESSION['UserName'] has been set, then checks if it has been set to something other than an empty string.
You can simply call this as:
<?php
if($_SESSION['UserName'] == ""){
?>
<body onload="showUser(), showChat()">
<?php
}
else
{
?>
<body onload="showUser(), showChat(), Login();">
<?php
}
?>
加载中,请稍侯......
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