Ok, so I am building a CMS one of the features I wanted to add is ability for me to send messages to my friends which are also using the CMS currently in development mode. This point of the idea is to allow more fluent communication between me and them, since e-mail can be delayed sometimes and here i want to send a simple message to them. With something like following format
Name:
Avatar:
Subject:
Date:
Message:
I am pretty sure this can be easily rigged together with PHP and JSON just assuring the access to the JSON file is secure in which I implemented something like access key which checks if the site requesting the file matches site host, and matches the key.
In any case sorry for my babling, this is my way. But folks I would like to know what would you suggest in making cross-domain messaging system build in into a PHP + jQuery based CMS? In terms of being robust, fast, secure and easy to work with.
Exchange data in the jsonp format, http://en.wikipedia.org/wiki/JSONP.
Server:
How to convert php to jsonp with json_encode.
http://1080d.com/lang/en-us/2009/10/converting-php-to-jsonp-with-json_encode/
Client:
Ajax example of jsonp data call. This particular example concerns the timeout feature but is an excellent example of how to set it up.
jQuery ajax (jsonp) ignores a timeout and doesn't fire the error event
Related
I am looking to create a Web Chat system using PHP, MySQL and JavaScript.
Currently, I am storing messages in a MySQL database with an incremental ID (Yes, it is indexed), a timestamp, the sender, and the message itself. I am then using AJAX to query the database every 500ms, seeing if there are any more recent messages than the last one received. However, I have a feeling that this is probably horribly inefficient as it will result in a large load on the MySQL server when multiple users are online. Having looked around a bit on Google and on here, everything seems to point to this way of doing it.
My question: is there a better way to do this? Any tips on how to reduce the load on the server would also be welcome.
I'm using PHP 5.3, on an Apache webserver, so libraries or plugins compatible with those would be fine.
EDIT:
Forgot to mention in the original post, but I'm not worried about supporting IE or other outdated browsers.
Potentially viable basic approach:
Cache your 50 most recent messages in memcache. Reset this whenever a new entry is added to the database. When new users connect, serve them these 50 messages to populate their chatroom.
Use a third party service like http://www.pubnub.com/ to send messages to your clients. Whenever a new message is sent to your chatroom, send it out on pubnub. Your server code will do this after writing to your database successfully.
notes: I'm not affiliated with pubnub. You don't need to use 50 messages above either. You don't even have to give them any messages when they connect depending on how you want to set it up. The point is that you want to avoid your users reading from your database in this case - that model isn't likely to scale for this type of application.
Ideally, an evented environment would be ideal for this kind of app. The LAMP stack is not particularly well suited.
I would recommend using this library, Pubnub. Pubnub is an easy way to send radio signals via javascript, or any TCP language (such as PHP) - and javascript instantly recieves the sent messages.
In PHP, you could simply have it save to your database - then use Pubnub's PHP API's to send the message to everyone else on the page.
If your familiar with Html, Javascript, and PHP - it can be fairly easy to learn. I would recommend it.
You are asking about a web chat system specifically built in PHP, MySQL and HTML with JavaScript. There are many options including Pre-built solutions: http://www.cometchat.com/ and http://www.arrowchat.com/ which all have chat comet services powered by a cloud offering like http://www.pubnub.com/ with options to host it yourself. See more about CometServices http://www.cometchat.com/cometservice/third-party-alternatives where you compare the service providers. There are several more options, however I recommend starting there. If you needs something more simple, like HTML and JavaScript only solution, you can check out http://www.pubnub.com/blog/build-real-time-web-apps-easy which is a blog about building real-time web apps easy with an example chat app in 10 lines of JavaScript Code. The solution Cuts Development Time by providing full Cross Platform for all browsers and mobile devices.
You should look into ajax long polling, in a nutshell this a simple ajax call but will not return a result from the server if there is no new data. You just do a simple loop on the server side until new data will be available then return it. Of course you have to stop this eventually if there's no result to send to client after a while (eg. 1 minute) then restart the call.
I suppose, that chat is too intensive for storage engines MySQL. Maybe, MEMORY table type will be ok, never used it. I spoken to several developers and everybody agree, that best option for chat is Memcache or even writing your own custom daemon (with memory-only storage as weel).
For client part you may read about short-polling, long-poling and web-sockets / sockets via flash/Java object.
using AJAX to query the database every 500ms
Is short-polling.
Sockets are a better solution than AJAX polling, however isn't much around about how you can integrate socket based chats with MySQL.
I have done a few tests and have a basic example working here: https://github.com/andrefigueira/PHP-MySQL-Sockets-Chat
It makes use of Ratchet (http://socketo.me/) for the creation of the chat server in PHP.
And you can send chat messages to the DB by sending the server JSON with the information of who is chatting, (if of course you have user sessions)
So i'm working on an A/B tester website, similar to http://www.optimizely.com/ and i'm quite new to web development. An A/B tester pretty much allows clients to create variants of their website to make optimizations based on user response (mouse clicks, etc.). So once the variants are made on our website (e.g. larger button size), my job is to send a package to the client which allows them to access and run the javascripts of the variants on the clients end when their page loads. Do i need an ajax call to send this data or can it be done via https request and what are the pros and cons for what i need done? (We're using mysql, hadoop and php). Thanks.
This question doesn't make a lot of sense to me.
HTTPS is a communication protocol. AJAX is a programming pattern (or, perhaps more cynically, buzzword). AJAX most often would use HTTPS to accomplish the actual secure communication between client and server.
If I understand correctly what you mean....
Depends of what data is being sent - if it is personal data, always use HTTPS calls (ie. request the data from https://yourdomain.com/your_script.php), otherwise HTTP (ie. http://yourdomain.com/your_script.php) will be ok (both of these can be done via ajax, so that's not a problem).
OK,
I'm not entirely clear how to ask this question, so please feel free to edit it.
Here's the idea.
I have a database that I think may be useful to webmasters.
I would like to offer, as a paid service, the inclusion of some interface with the database.
I want my database to dynamically populate drop-down option menus.
I understand how to do it when the database, requesting html/javascript and the processing php are all on the same server.
I'm not so sure whether this can be done if the requesting html html/javascript are on the webmaster's server, and the processing phps and the database are on my server.
I'm also not sure how to make sure that only authorized users can hook up to my database.
At this point, I am looking for a macro-level solution, not the code implementation.
Thanks!
Instead of directly connecting to remote database server, I suggest you to create a simple web service (such as a PHP page grabbing information from database, based on the request stated in query string you specified ) to generate XML / JSON for your web page.
Your web page, containing your drop down box, can make an AJAX request to fetch the XML & parse for data. With this mechanism, security problem caused by exposing the database can be avoided.
My approach to this would be to write a web service (whether SOAP, XMLRPC or REST) that requires the users to submit an API key with each request. The service would validate the key, talk to the database, and return results to the user in some standard format. The API key would (obviously) be unique for each user/subscription.
You could return the results of the request to the php script in JSONP format (json with padding). That allows the javascript to execute a callback method on the original webpage even though the service is on another domain.
You'd probably need some way of tracking state in your php code to determine if they're authenticated. One way would be to have the author of the 3rd-party webpage send an authentication token during their body onload to your php script. You could then mark the IP address of the client as "authenticated" and then all other requests from that same IP would return a valid result. Requests from a non-authenticated IP could return an error message.
IPs are obviously not unique in our world of NAT (network address translation). If you want it to be more fool-proof, you could generate your own token inside the PHP & send it back from the request to authenticate. The 3rd-party site would store that token in memory (or a cookie) & send it back to you on every request. You'd use that token as the proof of authentication on future requests, rather than the IP. This is basically how most servers do Sessions, PHP probably has something built in for that.
I want to write a PHP script that performs a routine task in a web app I use. I am trying to figure out the easiest way to submit a form, click a link, and get some information. What's the easiest way to do this (keeping the session open, etc.).
Javascript would be a better solution than PHP. You can use it in tandem with PHP to submit a form that references the same page, ie. <form method='index.php' action='post'>
If method is GET then you ought to be able to work it out form the URLs of a few real world attempts.
It POST then you are probably SOL unless it's your own web page./app and you know what $_POST it expects ... unless you find a tool to snoop your HTTP traffic and get the POST info from observing a few real wrold examples.
You can use CURL in PHP to simulate submitting data, clicked links, etc., I suppose, but a client-side scripting language like Javascript--as opposed to a server-side language like PHP--is more suited to what you're describing. I'd need more info to give you a specific example.
You will not be able directly emulate those events in PHP as web apps use Javascript on the client side and PHP is a different language and operates on the server side.
Firstly, I would see if there is an open API available for the web app you're wondering about, e.g. Gmail: http://code.google.com/apis/gmail/ . Not all APIs can do what the web app can do, so you'll need to check the documentation to make sure the API does what you want and has an easy way to interface with PHP.
The other option is to essentially reverse engineer how the web app communicates with it's server. Most all web apps operate by sending POST or GET HTTP data in some sort of serialized format like XML, JSON or text. You can use something like the Firebug add-on for Firefox to view POST/GET data. If you know what the server sends to the client and what the client sends to the server, you can essentially write a script using something like CURL to emulate the client in PHP instead of JavaScript. This would take quite a bit of work and probably involves a lot of trail & error.
Is it possible for a web page using Javascript to get data from another website? In my case I want to get it for calculations and graphing a chart. But I'm not sure if this is possible or not due to security concerns. If it is considered a no no but there is a work around I would appreciate being told the work around. I don't want to have to gather this information on the server side if possible.
Any and all help is appreciated.
Learn about JSONP format and cross-site requests (http://en.wikipedia.org/wiki/JSON#JSONP).
You may need to use the "PHP-proxy" script at your server side which will get the information from the websites and provide it to yours Javascript.
The only reliable way is to let "your" webserver act as a proxy. In PHP you can use curl() to fire a HTTP request to an external site and then just echo the response.
You can't pull data from another server due to the same origin policy. You can do some tricks to get around it, such as putting the URL in a <script> tag, but in your case it wouldn't work for just parsing HTML.
Use simple_dom_html, to parse your data server side. it is much easier than doing it in JavaScript anyways.
A simple way you might be able to do this is to use an inline iframe. If the web page you are getting the data from has no headers, or you can isolate the data being pulled in (to say an image or SWF), this might work.
cross-domain javascript used to be impossible, using a (php-)proxy was a workaround for that.
jsonp changes this entirely, it allows to request javascript from another server (if it has an API that supports jsonp, a lot of the bigger webplayers like google, twitter, yahoo, ... do), specifying the callback-function in your code that needs to be triggered to act on the response.
the response in javascript will contain:
a call to a callback-function you defined
the actual payload as a javascript-object.
frameworks like jquery offer easy support for jsonp out of the box.
once you have the raw data you could tie into google chart tools to create graphs on the fly and insert them in your webapp.
Also worth considering is support for XMLHttpRequest Access Control which is support in some modern browsers.
If the service provider that you are trying to access via a web page has this set up, it is a very simple call to XMLHttpRequest and you will get access to the resources on that site without the need for JSONP (especially useful for requests that are not GET, i.e. POST, HEAD etc)