如果PHP中的条件为true，如何自动显示按钮? [英] How to auto display button if condition in PHP is true?
问题描述
如果PHP中的IF条件为true，我想自动显示(不刷新页面)按钮.
I want to auto display (without refreshing the page) button if, IF condition in PHP is true.
我尝试过:
<?php if($diffex >= "90"){ ?>
<button class="btn btn-large btn-primary" type="submit" style="float:right;" name="btn-resend">
Resend OTP
</button>
<?php } ?>
但是上面的代码需要刷新页面，我希望不刷新页面.
But the above code needs the page to be refreshed and I want it without refreshing it.
我的$diffex的计算公式如下:
<?php
$eotd="";
$otd="";
if(isset($_GET['od'])){
$eotd = $_GET['od'];
$otd = base64_decode($eotd);
}
date_default_timezone_set('Asia/Calcutta');
$cdate = date('Y-m-d H:i:s ', time());
$scdate = strtotime($cdate);
$dscdate = base64_encode($cdate);
$deotd = strtotime($otd);
$diffex = $scdate - $deotd;
?>
实际上，如果the current time比URL中的时间大90s
Actually, I need this for displaying Resend Option if the current time is greater than the time in URL by 90s
推荐答案
正如您已经指出的那样，在PHP的服务器端无法做到这一点.每当需要显示或隐藏按钮时，您都需要在客户端运行JavaScript来更新DOM.
As you've already noted, there is no way to do this in server-side in PHP. You'll need JavaScript running on the client side to update the DOM whenever the button should be displayed or hidden.
在最简单的级别上，按照您的要求进行操作，您可能最终会将AJAX请求发送到PHP脚本，该脚本将响应JSON中的客户端JavaScript.有了这些数据后，您可以从那里更新视图.
At the simplest level, to do what you're asking, you'll probably end up sending AJAX requests to a PHP script that will respond to your client-side JavaScript in JSON. Once you have that data, you can update the view from there.
示例:
check_diffex.php
<?php
header('Content-Type: application/json');
// You would calculate a real value here
echo json_encode([
'diffex' => 101
]);
JavaScript
var checkState = function(){
jQuery.ajax({
url: '/check_diffex.php'
}).done(function(data){
var button = jQuery("#myButton");
if(data.diffex >= 90) {
button.show();
} else {
button.hide();
}
});
}
checkState();
setInterval(checkState, 10);
带有诸如本机JavaScript和jQuery之类的棘手部分是决定如何构建代码来检查diffex >= 90与您的应用程序的其余部分.即使是最简单的如果这样，那么那个"检查，很多快速而肮脏的实现都会迅速变得令人头疼.
The tricky part with something like native JavaScript and jQuery is deciding how to structure your code that checks that diffex >= 90 with the rest of your application. A lot of quick and dirty implementations will quickly turn into a headache, even for the simplest of "if this, then that" checks.
这些天来，您要执行的操作中最易于访问且可维护的方法是采用单页应用程序(SPA)框架，例如:
These days, the most accessible and maintainable way to do what you're asking is to adopt a Single Page Application (SPA) framework, such as:
- Vue.js
- Angular
- React
我强烈建议您看一下Vue，因为您可以将它集成到现有项目中，而不必重写整个前端.
I highly recommend you take a look at Vue, as you can integrate it into existing projects without having to rewrite the entire front-end.
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