I'm doing some updates for an intranet i created few years ago using ASP Classic. What i've been ask to do is to ALERT all users when news on intranet is added. Basically i need to check on database when news is added and than trigger an action to all intranet users saying you have New Message
I'have done a lot of research on this and i could't really find a good example for it.
Your help will be much appreciated.
Cheers
Vullnet
Basically to need to poll the server using AJAX and check for new messages.
I suppose you have a messages table with and ID that counts up. You need to track each user's last message pointer, and send this as part of your AJAX request ad a parameter. If the server's ID is higher thsn the user's then they have a new message.
Based on the AJAX response you then alert the user.
You need to make an ASP that responds to your AJAX call, Pass it a number and it responds with "OK" (not new) or "NEW".
IT works the same way, regardless of the server-side language. Use jQuery to perform your AJAX calls.
Related
Block or limit visitor's(just viewing a website, no user registration) multiple form submission in Laravel by getting client IP and saving it in database then use it to detect spamming visitors. is that possible?
I wouldn't recommend using a visitors IP to prevent future requests to your site via forms. IP's are very rarely static for the average user. If the user knows what they're doing, they'd just have to restart their internet connection and their ISP would give them a different IP address. Additionally, they could just proxy their requests utilising IP rotation to bypass your "security".
If you're trying to prevent bots from submitting forms. A good method is to implement a hidden input field with no value. If the form is submitted and the input field has been populated then you know it's a bot. It's not the most reliable method as the bot has to be a dumb bot.
The only truly "reliable" method I can think of is Client-Side > Server-Side validation such as Google ReCaptcha.
Ofcourse the alternate method is just accept that your form will get spammed and find a way to handle the spam after it's been submitted.
I want to make an online DB based chat application. My problem is to detect changes in the DB, i.e. whenever a user sends a message to another user it should display to him. One approach is Ajax calls with setinterval but I want an instant solution. I do not want to keep the server busy with such Ajax calls.
I need your help to solve next issue: I am developing MVC application and want to send instant messages between users. This message will ne standard - it's like notification. I am thinking about two optins:
use XMPP protocot, but I don't need the huge amount of options it could provide, I need just basic functionality I've discribed;
have some static array in MVC application with users invitations were send to and ajax function which will call controller action, check if user is in static list. If yes - make message visible on the page. And plus do page autoupdate. But I am not sure about this becouse array will be called very often.
What do you think, guys? Do you have any ideas? I will be very thankfull for any help!
You may take a look at SignalR.
Also checkout Jabbr which is built on SignalR:
https://github.com/davidfowl/JabbR
This is a chat application written by the author of SignalR David Fowler.
You can set jquery timer to update messages with ajax. And when user writes message , it can be saved in Cache or in database if you want to save it permanently.
I'm not typically a web developer, but I'm a decent enough coder that I felt comfortable accepting a proposal from a friend to develop his brother's small business website. I'm nearly finished and I've been using CodeIgniter, which has been a huge help and was easy to jump into.
They have a handful of products they'd like available for purchase via the site, their preference was Auth.net (which I have no previous experience with), and their host does not support SSL (nearlyfreespeech.net), so I decided that Auth.net's SIM was appropriate. If I test SIM outside of the CI application with a relay response page which simply spits out the available transaction details, everything goes as expected. If I try it with the relay response page set to a CI controller/method which simply echoes a string, Auth.net displays the following 'error':
An error occurred while trying to
report this transaction to the
merchant. An e-mail has been sent to
the merchant informing them of the
error. The following is the result of
the attempt to charge your credit
card.
This transaction has been approved.
It is advisable for you to contact the
merchant to verify that you will
receive the product or service.
My initial thought was that perhaps the rewrite rule I set up to circumvent having to include the index.php front controller was the issue, so I tried including it in the relay response URL with no change. I should also note that the controller in question implements a _remap() method, but the relay response method shouldn't be affected by it as it doesn't match it's regex.
Any insight(s) would be greatly appreciated.
This error occurs when your script doesn't respond within a specified amount of time. It also is displayed if anything other then a 200 success message is returned. So basically there is an error in your relay response URL.
You need to test this first by pulling up the page directly to see if it works and returns the proper header response. Then you can test it by sending a simulated POST response to it and see if it also responds properly. If those work make sure the script isn't taking too long to respond. If it is there probably are ways to optimize the slow page to give the response in the appropriate amount.
I'm wondering how it's implemented in Gmail, that every time you receive e-mail, the list of mails is automatically refreshed. It looks like the server is sending some kind of event to the browser, but how is it possible? Or maybe it’s simle: the browser ask the server for new messages every let’s say 2 seconds? But it would probably kill the performance…
Anyone have some ideas?
EDIT: OK, so if it's the simple answer, how do they manage performance? When I send an email from an other account to the gmail account the view is "refreshed" almost instantly. You were saying about a simple function that returns true / false, but it must have some logic (db connection or reads some files). How they manage it?
See also: How is GMail Chat able to make AJAX requests without client interaction?
Dont know exactly which technoloy Gmail uses, but the concept is to open a channel - using reverse AJAX, comet or sprocket based techniques.
Think of it as the client requesting the server for data, but the server does not return for one minute unless it has new mail. Using this technique, the client can almost show the results in a real time manner and it does not have to poll every 2 secs. Makes sense?
gmail is, in fact, polling the server for updates. Not as often as every two seconds, though. That would be madness. A bit of testing with Tamper Data makes it look like maybe every 20 seconds, though there seem to be multiple events going through that confuse it a bit.
Regarding your edit, I imagine they might have a last-activity timestamp on the account tracking in their database, with the client polling query retrieving that via Ajax and comparing with its last sync to determine whether it needs to do a full update.
You have right with simple answer. Google Mail checking new messages on server via AJAX.
It must be some kind of ajax listener that get informations every X seconds.
I already set something like that for one of my projects. What I was doing is calling a function that was returning true or false. True if the page needed to be refreshed, false otherwise. Then if you have an update, you do another call to get the actual update. This way you don't have to refresh everything every time... but it's still intense on the server if you have a lot of users.
In other words and like chaos said, it's polling the server.