I have a dashboard set up to automatically refresh the page and data. I want to move away from that and only refresh divs. The only issue is that the data i am calling is from the back end and not a separate file. I have the following code:
<script> var auto_refresh =setInterval(function({$('#test_refresh').fadeOut('slow').fadeIn("slow");}, 10000);
Year to Date Sales<span id="test_refresh"> $<?=$this->YTDsales?></span>
Obviously the data is not refreshing, it's more or less of an effect. Is there a way to just refresh single php data? Thanks for any help.
I wouldn't recomend to do a refresh via javascript, I would rather go through a simpler and cleaner solution try to do a polling or use websockets and update/get the information almost in real time.
look at this answer and you may get a clearer concept of what I'm suggesting and this is a practical example of a long polling in php
I hope that helps,
cheers!
I have a very large site and it takes pretty long time to load. It takes around 120 seconds. What I'm trying to do is loads 1st half of the site loads 1st. Then user can surf while others parts are being loaded.
What I'm trying to do is below.
1st of all is this possible ?
According to my knowledge Yes since Google PageSpeed does that. But the problem is if I use PageSpeed I would have to change my DNS server settings and etc. I would like to do this myself.
How can I get it done ?
What type of technology should I use ?
Given that pages have the .php extension and written in PHP language.
You can use the concept of lazy loading.
You can load only content that is necessary during the load then using jquery and ajax you can load the remaining content.
In this way user can surf and interact easily with the the part already loaded while the other part will be loading asynchronously.
jQuery ajax or post method can help you on this.
A simple example could be,
If There are 5 parts of contents in your page, 2 needs to be loaded immediately
The page will be loaded with 2 parts loaded, so it will take quite less time than 5 parts loading
After document is loaded you will use ajax to load the remaining 3 parts.
Ajax will send request to the specific page of your website(can be possibly named AjaxRequestHandler.php) with some parameters, and this page will process your request and generate html for this and will send it back to your main page which will just show this returned html and this all be happening asynchronously, so the user will be able to communicate with the initially loaded 2 parts
And even if you are new to web technologies, I suppose you have to have the knowledge of atleast ajax and asynchronous calls etc. to achieve lazy loading.
Edit :
For your this question
Except AJAX Is there way around for this?
I think you can try iframes if they can help.
Loading the main content in the page load without iframe while loading other contents in the iframes after pages is loaded.
This jsFiddle
jsfiddle.net/cGDuV/
can help you understand lazy loading with iframe, mentioned in this post of stackoverflow.
You can use javascript for the same if you want to avoid jquery.
You can manipulate the output buffer such that it flushes early thus achieving what your after in the screenshot you posted in your question.
http://www.stevesouders.com/blog/2013/01/31/http-archive-adding-flush/
You can lazyload all your images. Here's a jquery plugin that does it easily
http://www.appelsiini.net/projects/lazyload
You can combine all your js in one file. Same with your css files. This will help the speed.
You can incorporate caching, expires headers and gzip/deflate compression
https://github.com/h5bp/html5-boilerplate/blob/master/dist/.htaccess
I would suggest you load your 3rd party javascript widget garbage (Google+ buttons, fabebook like buttons, social, twitter stuff) in a non blocking asynchronous way so it does not slow down the page in the beginning.
http://css-tricks.com/thinking-async/
Optimize your images as much as possible.
http://kraken.io/
Use a CDN
http://www.maxcdn.com/
Finally test your site and see where is the big bottleneck and where you can improve the site for speed optimization. Use the waterfall chart feature
http://www.webpagetest.org/
One of the things you can do is to load all the essential (top half) of the page normally, then use javascript/ajax to load the second half of the page. This is a very common technique (and is often used to load images).
Here is an excellent tutorial from jQuery for Designers, walking through how to use jQuery to load images asynchronously after the page loads. http://jqueryfordesigners.com/image-loading/
Having said that, a two minute load time seems very excessive. Maybe you should check if there is anything that could be slowing down your server.
You need to determine why the site is loading slow. What is the size of the data you are sending? Google and Firefox have web developer tools to help you determine which elements are taking the longest too load. Once you've determined the culprit, try to load the worst offenders asynchronously.
Check out this article on aync requests: https://segment.io/blog/how-to-make-async-requests-in-php/
in my opinion you need an endless scrolling solution. That is, have a fixed amount of content per "page" (could be an estimated 1500px worth of height). Use jQuery to load another "page" when user scrolls down by a set amount.
If you really want to unconditionally load all the content, just use the same approach, and on document ready trigger the next page to load. The loop the page loader until the whole thing is loaded. That way, you load the first "page", and defer the content "below the fold" to subsequent requests.
What you want is what Facebook does Bigpipe and here is a relevant SO post: Facebook Bigpipe Technique Algorithm
There are other solutions involving all sorts of Javascript but since you want PHP and Facebook uses PHP you should read up on Bigpipe. Juho even has an example written in PHP so that should meet your PHP requirements (but yes it still requires js but not AJAX).
Prefetching Resources the web page require large files for loading can often benefited from changing the order that those files are requested from the server. Sometimes, it makes sense to download files before they are necessary, so that they are instantly available once requested. When the resources required for a page can be loaded in advance, the user-perceived network latency for that page can be significantly reduced or even eliminated. When you run Google pagespeed insights and see the result, you will see how the fix the problems in your website.
Some tips to load site faster:
Make fewer HTTP requests
Add a far-future expires header
Gzip your page's components
Minify your JavaScript, CSS and HTML
One more thing when loading a webpage and if you are using php with smarty you can use this plugin which reduces the number of http requests to you server and makes the site load faster by combining all the js and css resource's request into one single HTTP request.
Alternatively you might be looking for these plugins.
http://masonry.desandro.com/
http://isotope.metafizzy.co/
http://www.wookmark.com/jquery-plugin
Does all this stuff have to be on the same page? Does it make sense to split the content over multiple pages? Can some of it be delayed until the person requests it? Can it be grouped into tabs? Hidden tabs could be lazy loaded for instance.
Give serious thought to restructuring the content in other ways. You might be able to come up with an alternate arrangement that simplifies the problem.
Having in mind all that was mentioned above you may think of caching parts of your data/html code with memcache or in any other way possible so you skip its generation every time. Of course this depends pretty much on how often the data changes.
Don't browsers render the document as it comes in? Whatever you put at the top of the file will be received by the client first, and therefore will be displayed first. For example, when you try to view a very large image file online, it loads from top to bottom. The same is true for web pages. Just put the content you want to load first at the top of the page!
Answer to question one: yes
Answer to question two: above
Answer to question three: Nothing, just put the page in the correct order.
Well the idea is more or less the same as described by Pawan Nogariya above. You will need to fetch views and data asynchronously and then display these. But this means that you will never redirect or post back to any other page rather will get every view via ajaz. This will make you application SPA (Single Page Application) like Gmail. And, this will also mean you need to keep track of what has been renedered and what not, leaving you in a mess. So, instead of doing everything your way there are already developed and popular frameworks available that let you do that but they also make it SPA. Which means that your application doesnt "posts" to the server as in redirection but everything is doen using Ajax.
You can use Backbone (Backbone.js), Knockout (Knockout.js) and may others to achieve this. These are javascript based frameworks that help achieving what you have just asked and may expample and tutorials are also easily available. You can use it with any language as we are using it with C# (MVC) for a relatively large applicaiton.
this is going to be ugly! You should definitely consider using ajax calls to load page fragments AFTER a first content stage is loaded!
This is going to break almost all known web standards, but it might render the website in parts....
this being said: here's the ugly stuff
First: get rid of the <html> tag of your website, start with the <head> DO NOT use a <body> tag either.
Now send your html-code in the order you want it to be loaded (top first) using echo ...
after each closing tag of a group (say </table> or </div>) use flush(); ob_flush(); this will send all known content to the browser immediately.
The browser now decides if it can render the known content or not and if it will (based on the browser specifics and user settings) but with few exceptions it will.
some browsers like to wait for the closing body-tag that's why we dropped it, others even wait for the closing html tag (safari afair) that's why we dropped that too.
If you use the echo-flush scenario wisely you should be able to split the page into renderable parts which most browsers will display without an error.
Again... don't do it this way.. it's bad, ugly and not even near any web standards
But you asked for it.
For your this question
Except AJAX Is there way around for this?
I think you can try iframes if they can help.
Loading the main content in the page load without iframe while loading other contents in the iframes after pages is loaded.
This jsFiddle
jsfiddle.net/cGDuV/
can help you understand lazy loading with iframe, mentioned in this post of stackoverflow.
You can use javascript for the same if you want to avoid jquery.
With pure PHP? Not smart.
$(function() {
$('#body').delay(1).fadeOut();
});
Fiddle example: http://jsfiddle.net/r7MgY/
I have a little bit of a conundrum. Basically I'm developing a WYSIWYG Editor plugin for jQuery specifically for my web application. One of the features will be inserting an inline image tooltip based on the images a user has uploaded. For example:
Hello there my name is [i="profile_pic.png"]A. Username[/i]
The part that I'm having an issue with is, when defining which images are available to a user, whether I should insert the PHP array directly into the Javascript like so:
var available_images = "<?=json_encode($User->Profile->images)?>";
or to go for an Ajax GET that returns an encoded array of the image sources? I think the inline php makes more sense since it removes the need for an unnecessary ajax call but I didn't think that inserting inline php into javascript is terribly good form?
Any suggestions?
There's nothing wrong with inserting data collected by PHP into JS, how else would JS get the data? The only reason you should consider the AJAX call would be, if users could upload new images while they are editing. This would mean the information needs to be updated, which would make the AJAX call more appealing than the static JSON on page load.
Unless the array changes in any way over the life time of the page, then I'd spit out the array exactly as you suggest in your code snippet. There isn't any real benefit to having an extra ajax call because the size of the array I'm guessing won't be so huge as to impact the initial page load time.
If you look around the Stack Overflow pages and do view-source, they do this sort of thing all the time.
If the amount of data is huge and maybe adds a seven or more seconds to the page load time then I'd consider an ajax call. At least the page is rendered and the user has something to look at, meanwhile you can have a throbber image with a status message saying loading or whatever.
I'd also say that I see a lot of unnecessary ajax goings on just for the sake of it. It's like premature optimisation, people adding complexity to solve a problem they don't have. Start off simple as you're doing, if you're having response time issues down the road with the said page, then consider what benefits ajax will bring to the table.
Do you always get the array of images, or only sometimes (e.g. in response to a user's action)? If the former, I'd say do it inline. Otherwise do it as AJAX. i.e. only do it by AJAX if it'll reduce your traffic etc. But if you have to always do it, I don't see any advantage. I don't see any problem with mixing inline php and javascript, other than it means you have to do your javascript inline too instead of in external .js files that can be cached (or at least the part where you populate your array).
I want to write a php code that displays a html button only till some point of time.
Since php is a scripting language and code get executed only when the html page is rendered,
I was thinking that instead of polling I can just check the time at the time the page is getting rendered. If the current time does not satisfy my condition then I simply won't echo that button else I can echo the button.
Is this approach right or should I do polling ?
Once the page loads, php has no more control. If you have displayed a button, and you want to remove it after a certain time frame, you will need to use javascript anddo some kind of setTimeout() to schedule that. Obviously, the javascript won't be 100% reliable (if someone has js disabled, or a browser not supporting js).
I don't understand why you would use polling. PHP already has all needed functionality to both check the time and to conditionally output HTML. The only thing that may cause trouble is timezones, but that can be handled by adding an offset to the relevant times.
I'm trying to speed up response times in my ajax web application by doing the following:
Say the user requests a page whose contents don't change (e.g a web form). When the user makes a different request, I 'cache' the form by putting it in a hidden div. Before displaying the new information. So the form is basically still loaded in the browser but not visible to the user. If the user requests the same form again, it gets loaded from the hidden div. That's notably faster than doing a round-trip to the server for the form.
I do realise doing so with lots of data will probably degrade performance as the browser gets to keep a lot in memory. But I will place a limit on how much gets "cached" this way.
Now, I came up with this on my own which is why I'd like to know if there is a better/established way of doing this. It works as expected but I don't know what the possible drawbacks are (security-related perhaps?).
I would appreciate any suggestions.
Many thanks.
I've done this before. It can be a useful technique. Just make sure the data is accurate and that you support JS disabled user agents.
EDIT: And that there is no better solution.
Storing the HTML code for your form in a JS variable is probably more efficient than having a hidden div with the interpretation of this HTML code (form + form fields + various markup).
If your form code is generated at the same time as the page, simply print it in a JS variable :
<script language="javascript">
var myFormCode = '<? echo $myFormCode; ?>';
</script>
(That's if you use PHP...other languages shouldn't be far from that)
If your form code is generated later, you can send it as text via JSON :
<?php
echo json_encode($myFormCode);
?>
...and then build your form when needed, with something like that on the client side :
<script language="javascript">
myRealFormDiv.innerHTML = eval(myJSONEncodedTextIGotViaAJAX);
</script>
JS code is obviously not exactly what you need to type in, but you probably see my point.
This should work and is the best solution I can think of. Whether there are any security implications really depends on your forms and how they work - nobody will be able to diagnose this without actual code.
What about use APC or Memcached ?
They'll allow you to keep the html markup clean, with not 'hidden tricks' that could potentially create problems (user dont have css enabled? use IE6? what about accessibility?)
Depends on your needs, but in general way the page must contain just what it must containt, nothing else.
Another way of doing this is to set the "Expires" or "Cache-Control" HTTP headers for the form.
If you set an "Expires" header 1 hour in the future for url http://example.com/form.html, then the next time within an hour that the user navigates to that form the HTML will be loaded without touching the server.
If you properly version your images/CSS/JS and give them far-future "Expires" headers as well, then there will be no server roundtrip, plus you'll help the performance the rest of your pages.