Loading XML data without refresh - php

Question

I've script which get some values from XML record.
There's code:
<?php
//Data
$xml_data = '<image_process_call><image_url>https://i.pinimg.com/originals/e4/41/54/e44154308e3466d987665c6d50887f06.jpg</image_url><methods_list><method><name>collage</name><params>template_name=Nun Face in Hole;</params></method></methods_list><result_format>jpg</result_format><result_size>800</result_size><template_watermark>false</template_watermark></image_process_call>';
//Settings
$app_id = '';
$key = '';
$sign_data = hash_hmac('SHA1', $xml_data, $key);
//Send request
$request_url = 'http://opeapi.ws.pho.to/addtask?data='. $xml_data .'&sign_data='. $sign_data .'&app_id='. $app_id;
$request_xml = simplexml_load_file($request_url);
$request_id = strval($request_xml -> request_id);
if (isset($request_id)) {
$result_url = 'http://opeapi.ws.pho.to/getresult?request_id='. $request_id;
sleep(6);
$result_xml = simplexml_load_file($result_url);
$result_status = strval($result_xml -> status);
$result_img = strval($result_xml -> result_url);
if (isset($result_img)) {
echo $result_img;
} else {
echo 'Result image not found';
}
} else {
echo 'Request ID not found';
}
?>
The problem depends on time to generate the second XML file. $result_xml took few seconds so I have to use sleep(6) function.
If I remove this, I need to refresh the page (minimum three times) to get a link to generated image from second XML.
Do you have an idea how to do it more professionally? I can't be sure that every image will be generated in 6 seconds (sometimes shorter sometimes longer).
Is there any method for genereting the result only after receiving $result_img? Thanks in advance for your help!
I think it is worth writing.
In practice, it looks like this:
Script does $request_xml and XML from site return:
<image_process_response>
<request_id>2d8d4dec-4344-4df0-a1e1-0c8df304ad11</request_id>
<status>OK</status>
<description/>
<err_code>0</err_code>
</image_process_response>
Script gets request_id from this XML and do $result_xml. However, this is XML and script doesn't get image's url immediately. It needs to wait a few seconds.
After three times refreshing the page or using sleep(6) function finally we get:
<image_process_response>
<request_id>2d8d4dec-4344-4df0-a1e1-0c8df304ad11</request_id>
<status>OK</status>
<result_url>
http://worker-images.ws.pho.to/i1/9F1E2EAF-5B31-4407-8779-9A85F35862D3.jpg
</result_url>
<result_url_alt>
http://worker-images.ws.pho.to.s3.amazonaws.com/i1/9F1E2EAF-5B31-4407-8779-9A85F35862D3.jpg
</result_url_alt>
<limited_image_url>
http://worker-images.ws.pho.to/i1/3F797C83-2C2E-401C-B4AF-C4D36BBD442D.jpg
</limited_image_url>
<nowm_image_url>
http://worker-images.ws.pho.to/i1/9F1E2EAF-5B31-4407-8779-9A85F35862D3.jpg
</nowm_image_url>
<duration>2950.879097ms</duration>
<total_duration>2956.124067ms</total_duration>
</image_process_response>
Edit:
After trying to immediately generate the image I get such an XML:
<image_process_response>
<request_id>e615f0a1-ddee-4d81-94c4-a392f8f123e8</request_id>
<status>InProgress</status>
<description>The task is in progress, you need to wait for sometime.</description>
</image_process_response>
So this is reason why I see blank page...
Do someone have an idea how to force a script to reconnect with the second XML until it finds a result_url?

Answer 1

The problem depends on time to generate the second XML file.
$result_xml took few seconds so I have to use sleep(6) function. If I
remove this, I need to refresh the page (minimum three times) to get a
link to generated image from second XML.
Do you have an idea how to do it more professionally? I can't be sure
that every image will be generated in 6 seconds (sometimes shorter
sometimes longer). Is there any method for genereting the result only
after receiving $result_img? Thanks in advance for your help!
According to Pho.to API, An add task request is a queued POST request.
In my opinion, Send request in while-loop, but wait for smaller time instead of fixed 6 seconds, Check the status in image_process_response, Keep looping until it is not InProgress, After that, You can safely send second request to get processed image result.
You may encounter timeout issue due to low timeout configuration for DoS protection if you run this script on web server (via CGI/FastCGI), To resolve this situation, You need a queue for adding task in your HTTP request, and then process it offline (means without web environment).