我可以告诉我的 php 函数在“file_get_contents”使用 php 代码中的 javascript 加载页面之前不执行吗？

Question

This is my php function:

$result = file_get_contents('https://www.example.com/index.php'); 
$regex = '/<img class="pic" src="(.*?)">/';   
preg_match($regex, $result, $matches);
 return($matches[1]);

it's a function to get a picture from that link, sometimes it return the picture, sometimes not, because the image in the site sometimes take seconde to load sometimes not. I want to prevent that from happening in my function, I want to delay the return until the image is loaded, i know this is not possible with php, sleep() didn't help, so I know that I must do it with javascript, but I don't know how to do it, please help ty!

Answer 1

If you'd like to load something asynchronously, I guess the simplest solution would be to launch another request from the client side, eg:

1. Load the page without the desired picture
2. Create a new script, that would be fetching that image URL on the server. Let's call in fetch-image.php for example.
3. Make sure your script will render the image and return correct Content-Type header. Samplescan be found here . For that your code will need modification, please see below.
4. Move your code, mentioned above to the new script
5. Replace the image src="/fetch-image.php" attribute with the path to the fetch script

Modified script:

$result = file_get_contents('https://www.example.com/index.php'); 
$regex = '/<img class="pic" src="(.*?)">/';   
preg_match($regex, $result, $matches);
echo file_get_contents($matches[1]);

Hope that helps.