Member Avatar for Member #564028

Is there a way to send a large amount of data through AJAX to a PHP script?

Almost all tutorials say to modify the URL to equal whatever variable your trying to look up. I am wondering if it is possible to pass infomation to the server through an XML or HTML document? Because having a whole array of information in the address bar can be kind of cumbersome.

  • 4 Contributors
  • 3 Replies
  • 2K Views
  • 2 Days Discussion Span
  • Latest Post Latest Post by digital-ether

Dani AI

Generated

@ragnarok511 You do not need to cram arrays into the query string. and are on the right track: send a request body and keep the URL clean. There is no single fixed URL-size limit across browsers or servers, so large payloads belong in the body. For really big data, @diafol’s pattern of sending a file or a server-side reference (an ID) and letting PHP do the heavy lifting is often more reliable.

A simple, modern approach is JSON over the Fetch API. Keep the URL minimal and put your array/object in the body:

const payload = { items: bigArray, note: "whatever else you need" };

const res = await fetch("/page.php", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify(payload)
});
if (!res.ok) throw new Error("HTTP " + res.status);

Fetch is widely supported and designed for request bodies like this. See the Fetch guide on MDN: Using the Fetch API.

When the payload is large, check server limits to avoid mysterious 413/empty $_POST issues:

  • PHP: raise post_max_size (and upload_max_filesize for files). If you submit thousands of form fields, watch max_input_vars. JSON you decode yourself is not counted toward max_input_vars.
  • Web server: increase the request-body cap (for example NGINX client_max_body_size; on Apache, LimitRequestBody).

If you are sending binary or very large data, prefer a file input and multipart/form-data via FormData, or chunk the payload and reassemble server-side. MDN’s FormData doc shows how to build these requests.

Recommended Answers

All 3 Replies

Member Avatar for jomanlk

You can send a POST request. That doesn't involve sending data through the URL so the 256KB limit won't apply. If you want to upload a file or something like that, it would be better to just post to and iframe so that the page doesn't refresh.

Member Avatar for Member #120589

It depends what you're trying to pass. You can pass any variable via POST (as mentioned), but I would suggest that you pass the filename of a text file (or XML or anything similar). Let the php script do the hard work of parsing / modifying the text.

Using a library like prototype or jquery may help with "messing with" the ajax object.

Member Avatar for digital-ether

You can POST raw data to the server if you needed.

This would be done by setting the correct HTTP headers:

http://www.w3.org/TR/2009/WD-XMLHttpRequest-20091119/#the-setrequestheader-method

Example: send XML data

var client = new XMLHttpRequest();
client.onreadystatechange = function() {
  // do your stuff
  if (this.readyState == 4) alert('sent');
};
client.open('POST', 'page.php', true);
// this controls the content type of the post
client. setRequestHeader('Content-Type', 'text/xml');
// we can send XML since we set content-type to xml
client.send('<user><name>joe</name><age>100</age></user>');

PHP can read the raw content using

$post_data = file_get_contents('php://input');

see: http://www.fijiwebdesign.com/fiji-web-design-blog/acess-the-http-request-headers-and-body-via-php.html

Note my XMLHttpRequest example will only work on W3C compliant implementations. To get an actually working example see:
http://code.google.com/p/xhr/
or
http://code.google.com/p/xmlhttprequest/

Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.