Page loading

NZ_Kiwis

I have a page which is going to display photos - a lot of photos. Each photo is a PHP script using GD lib to read a large picture on my server.

In preparation of this page I'm expecting loading performance to be slow.

Is there a way I can oard my page then load one image at a time and maybe display a loading gif until each image has been loaded and resized by my GD script.

There could be 200+ pictures per page (thumbnails)

NogDog

Sounds like a job for JavaScript. You could have the page populate a JavaScript array or JSON object with the relevant image URLs and related info, then have on onload event fire off a function that would change the image source for each relevant object.

Weedpacket

It may be better to generate the resized images in advance, so that they can be served immediately, rather than genearting and regenerating them every time they're needed.

Note that if you're using file-based sessions, only one image will be resized and served at a time, even if the browser makes several requests concurrently (because the session file gets locked by each script in turn), so if there are a lot then some of the requests make have to wait too long for their chance at the session file and hence to be run and the browser may give up on them and report the image as broken.

kredpl

This can do the trick:

function load(url) {
    // display loading image
    document.getElementById('loadingImg').visible = true;
    // request your data
    var req = new XMLHttpRequest();
    req.open("POST", url, true);

req.onreadystatechange = function () {
    if (req.readyState == 4 && req.status == 200) {
        // content is loaded. Hide the gif and display the content...
        if (req.responseText) {
            document.getElementById('content').innerHTML = req.responseText;
            document.getElementById('loadingImg').visible = false;
        }
    }
};
request.send(vars);
}

But much more important is to speed up your website. Lazy-loading webpage, even with the "Please wait while loading" GIF, won't be appreciated by potential users. Use gtmetrix.com website to fix the problems with website speed.