Is there any way you can push data to a page rather than checking for it periodically?

Obviously you can check for it periodically with ajax, but is there any way you can force the page to reload when a php script is executed?

Theoretically you can improve an ajax request's speed by having a table just for when the ajax function is supposed to execute (update a value in the table when the ajax function should retrieve new data from the database) but this still requires a sizable amount of memory and a mysql connection as well as still some waiting time while the query executes even when there isn't an update/you don't want to execute the ajax function that retrieves database data.

Is there any way to either make this even more efficient than querying a database and checking the table that stores the 'if updated' data OR tell the ajax function to execute from another page?

I guess node.js or HTML5 webSocket could be a viable solution as well?

Or you could store 'if updated' data in a text file? Any suggestions are wele.

Is there any way you can push data to a page rather than checking for it periodically?

Obviously you can check for it periodically with ajax, but is there any way you can force the page to reload when a php script is executed?

Theoretically you can improve an ajax request's speed by having a table just for when the ajax function is supposed to execute (update a value in the table when the ajax function should retrieve new data from the database) but this still requires a sizable amount of memory and a mysql connection as well as still some waiting time while the query executes even when there isn't an update/you don't want to execute the ajax function that retrieves database data.

Is there any way to either make this even more efficient than querying a database and checking the table that stores the 'if updated' data OR tell the ajax function to execute from another page?

I guess node.js or HTML5 webSocket could be a viable solution as well?

Or you could store 'if updated' data in a text file? Any suggestions are wele.

• php
• javascript
• jquery
• mysql
• ajax

Share Improve this question Follow asked Jul 9, 2012 at 17:11 Max HudsonMax Hudson 10.2k1515 gold badges6161 silver badges110110 bronze badges 4

• node.js by itself isn't an alternative. websockets are. You could use a websocket implementation within node.js, though, just as you could with many other server-side technologies. – Greg Pettit Commented Jul 9, 2012 at 17:20
• Which of the technologies you've put in tags actually do play a role with your question? And which role? – hakre Commented Jul 9, 2012 at 17:24
• All major server side technologies now propose websockets. I've seen at least node.js, Go and java. And I've see PHP too even if I'm not sure this makes a lot of sense apart for people already using it. – Denys Séguret Commented Jul 9, 2012 at 17:25
• Okay let's say javascript is node.js. So one tag is matched then. About Go and java has not been asked for I assume. – hakre Commented Jul 9, 2012 at 17:28

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4 Answers 4

Sorted by: Reset to default 2

You're basically talking about notifying the client (i.e. browser) of server-side events. It really es down to two things:

1. What web server are you using? (are you limited to a particular language?)
2. What browsers do you need to support?

Your best option is using WebSockets to do the job, anything beyond using web-sockets is a hack. Still, many "hacks" work just fine, I suggest you try Comet or AJAX long-polling.

There's a project called Atmosphere (and many more) that provide you with a solution suited towards the web server you are using and then will automatically pick the best option depending on the user's browser.

If you aren't limited by browsers and can pick your web stack then I suggest using SocketIO + nodejs. It's just my preference right now, WebSockets is still in it's infancy and things are going to get interesting once it starts to develop more. Sometimes my entire application isn't suited for nodejs, so I'll just offload the data operation to it alone.

Good luck.

Another possibility, if you can store the data in a simple format in a file, you update a file with the data and use the web server to check its timestamp.

Then the browser can poll, making HEAD requests, which will check the update times on the file to see if it needs an updated copy.

This avoids making a DB call for anything that doesn't change the data, but at the expense of keeping file system copies of important resources. It might be a good trade-off, though, if you can do this for active data, and roll them off after some time. You will need to ensure that you manage to change this on any call that updates the data.

It shares the synchronization risks of any systems with multiple copies of the same data, but it might be worth investigating if the enhanced responsiveness is worth the risks.

There was once a technology called "server push" that kept a Web server process sitting there waiting for more output from your script and forwarding it on to the client when it appeared. This was the hot new technology of 1995 and, while you can probably still do it, nobody does because it's a freakishly terrible idea.

So yeah, you can, but when you get there you'll most likely wish you hadn't.

Well you can (or will) with HTML5 Sockets.

This page has some great info about this technology:

http://www.html5rocks./en/tutorials/websockets/basics/