AJAX-based groupchat for webpage like on FB - javascript

Got a question for you ... I'm currently working on a simple groupchat functionality for a webpage. It will only be available for groups so there's no need for the users to specify a nickname or anything like that ... the nicknames will already be known to the system since the users have to be already logged in.
Anyways it should just be a simple chat room for the whole group - no 1on1 private chats!
Question is: Would you consider it a good idea to have a look into Ajax Push (like here for example) or is this overkill for a simple group chat ... don't expect toooo many people to use it that much so maybe push is overkill and longpulling via jquery would be better (in that case - do you know of any really good tutorial for a longpulling chat-functionality?)?
Any tipps or other input is greatly appreciated! :)
best regards
P

Pull would be easier, but would be a bigger load on the server and obviously not quite as real-time. For a good chat experience, push is definitely better. You may be limited on your ability to implement it, though, depending on what technologies you have on your server and how much control you have over it. I've implemented a push (Comet) system a few times, and it's definitely doable. It's really up to you. It sounds like you've got an okay handle on the things you should be considering (number of users, difficulty in implementing, etc). The more users you have, the better it's going to be to be using push because it'll take a lot of strain off the server, and it'll improve the interaction in the room.
Another thing to consider is what browsers you want to support. Supporting IE with push can be more difficult than supporting other browsers, but it's definitely doable (I've supported as far back as IE6 before).
Finally, if you only care about supporting modern browsers, you may want to consider using web sockets instead, as that would be both easier than push and better performing.

Related

Back-end solution for pure-Javascript site with link sharing

I'm developer-beginner and I would like to do simple card-sorting site.
hundreds of cards with plain text
no log-ins, it must be as simple for user as possible
few dozens users per day
final state of sorting should be saved under unique link, like site.com/q56we1cfuz4 or site.com/link.php?unique=q56we1cfuz4
User sorts cards as he/she wishes and the result is saved into browser sessions storage (few kb of data in JSON or so). So far, so good.
Question:
As I know only Javascript:
If I need to share the state of the page (data in session storage) with some unique link, is something like Firebase.com good solution for such kind of back-end? Or some simple DB with help od Node.js?
In order to "catch" the link when someone click at unique URL (site.com/link.php?unique=q56we1cfuz4), I still need some server-side script which will ask the DB, like PHP header redirect, right?
Your questions are a little fuzzy, no problem tho. You are just getting into web dev, so there's a lot to wrap your head around and all of the options can be pretty confusing. Some people will complain about opinionated answers, and I'm not going to claim to be objective here, but here are a few tips that I think will get you pointed in a better direction...
Firstly, yes - firebase is a good solution for you to try working with. Aside from the fact that it will give you the db/storage features you need, it's a realtime db, which will give you a lot more than just storage in the long run, and will better equip you for the future web development trends. The firebase API is (mostly) designed to work asynchronously, so from a javascript perspective, it falls right in line with the kind of code you'll end up learning to write.
Re: the other aspect of your question - server-side - check out nodeJS. It's basically a server-side javascript platform that will allow you to use the same skills you're learning to write client-side code for the server. Also check out expressJS, a nodeJS package that provides you the http-server, and allows you to handle dynamic urls, etc. - the bits you were thinking about when you made a reference to PHP.
Hopefully this will help you focus on a few specific tools to familiarize yourself with as you learn web development, rather than having to struggle with everything from new languages, platforms, and way too many libraries, frameworks and techniques to wrap your head around. Good luck!

Is it acceptable to no longer support javascript-disabled or non-ajax browsers for secured applications?

I'm curious about the current trend these days for ajax-applications. Is it acceptable to simply build an ajax application the best you can make it and simply ignore browsers that don't support ajax (assuming this a secured part of the site... not the public part)?
I am not talking about corporate intranets where you can reasonably control the browsers being used - but sites that people pay a monthly rate for. It's not quite public, but it's not controlled either.
It seems that the more you make your ajax application "kick ass", the harder it is to support the old model of doing things. The two models diverge further and further apart from each other that you're basically writing 2 UIs/controllers for everything in your system. Maybe in some cases you are writing 2 views too.
I'm the only developer working on this particular project. Having to double my efforts actually seems like a waste of time. I think I am better off building the product I want, and if it's successful, maybe go back and add the non-ajax stuff later (if at all).
The project's unique selling point - it's core domain - has a lot to do with the way I'm going to incorporate ajax. Frankly, supporting the non-ajax stuff isn't really that important to me. The software that doesn't support ajax is basically going to be a copy of what people are already using. The reason people would use this software is because it's a lot easier to use and it's lot more fun to use.
If people want the non-ajax version, there's already a lot of products out there that do that. I'm thinking it's smart to just say "screw it... that's a market I'm just going to ignore... and I'm going to bank on the fact that my product might eventually overtake them anyway."
Given this scenario, would it be reasonable to simply not support browsers with javascript disabled? If I did that, what things would I need to worry about, besides customers using older browsers and having problems?
If you can safely assume all of your users have JavaScript enabled or are able (and willing) to enable it for your site, you can require JavaScript.
However, you should still provide a meaningful, well-looking error page for those who do not have JavaScript. You could even add a guide how to enable (or allow - e.g. via NoScript) JavaScript for the site.

Writing a single page client-side only webpage

I'm considering to try out an idea, mostly for fun, and my question is if this is reasonable and if there are any libraries or frameworks that could make this experiment a little easier.
So, the idea: Basically it is to write a new UI for a website I've developed, but doing it with client-side code only. I can read/write data using ajax, since my existing website has an API that allows me to perform all kinds of queries. This allows me to use JavaScript for the whole thing and theoretically put all of the code in a single file.
Obviously there are limitations to circumvent; bookmarking, page refreshing, the back-button etc. But these limitations are what makes it interesting, right? :) I'm not so worried about search engine indexing, since one has to be logged in to use the site anyway.
The site itself is not overly complex, but it is not simple either. There are four different levels of users, multiple languages and quite a lot of data to be presented.
Is this a bad idea? If so, why would you advice against it? And do you know of any JavaScript frameworks or libraries that could make this easier? (And no, I'm not looking for an abstraction like Google Web Toolkit; I would like something purely JavaScript)
One of my coworkers did this. A nice feature of this concept was that you don't have a ton of POSTS whenever the user 'changes pages', since they are actually not ever changing a page until they submit their data for the final time. He did this for product registration software, which was nice. Our servers were only taking a hit when the user initially requested the page, and then when they submitted it.
The major, MAJOR downside to this concept is that most web developers are not expecting this. My coworker (and you) have a cool idea - but unless it is well implemented, with comments, 100% valid HTML, and a host of other good design principles in place, it can be confusing since most web developers have basically never seen this done before. His site was a nightmare to work with, as he did not actually know what engineering web software meant, and it was all slapped together. My organization never pursued this (potentially useful) idea because his implementation was so poor.
So, when I looked at this idea here were the trade-off I came up with:
1.) You cannot require any server-side interaction during intermediate pages.
2.) The initial page loading is longer, but there are no intermediate page requests (better optimization).
3.) This is vastly different than anything anyone usually does, which means you need to be especially careful with documentation.
4.) This design concept facilitates totally stand-alone web software to be easily deployed without the web.
5.) You might be increasing complexity for avoiding page loads, but maybe not. I'm not sure.
All together, I think it just depends on what you want to accomplish. My coworker really just wanted to see if he could do it, which he could. However, how he did it was really pretty bad, to the point where everyone else connected his poor implementation with a poor idea it was fairly sad.
Mostly, I think if you follow good web design practices this wouldn't be too bad of a thing to pursue. What are your goals though?
I'm sorry I couldn't directly answer all of your questions. I hope my experiences are still helpful in answering if I think it is a bad idea or not.
-Brian J. Stinar-
SproutCore is one of the best out there when it comes to really being built from the ground up for single-page, potentially complex applications. Unlike some others like GWT or Cappucino, SproutCore is really about using JavaScript directly. They aren't the only one though. You might also want to look at JavaScriptMVC and qooxdoo.
Personally, I've built an extremely large and complex single-page application using JavaScript. It is currently around 100,000 lines (including comments/whitespace). To give a sense of scale, jQuery is around 6,000. To reach that size, I built my own framework, build tools etc. and it is extremely maintainable. You're asking if it can work, and I can tell you that it does, but you do need a little infrastructure if you're looking at doing something big. (BTW, there's a lot of lazy loading - its not 100,000 lines all at once!)
I also wouldn't really recommend this method for anything other than a web application. As pointed out, its still difficult for SEO, and may be strange for some users.
You're looking for ExtJS
I did my site like that in jquery, backed by spring mvc 3. For me it works fine and you have a lightweight, flashy feling while on it.
If you have time to dig in javascript seriously... it is really good exercise.
The only thing I really need to add is SEO, since spiders see only intial html. If it is important for you, i think backend static files and sitemap would be good enough solution.
I found something very light-weight that provides the basic needed functionally without forcing you into a whole framework. It's called Sammy and is inspired by Ruby's Sinatra: http://code.quirkey.com/sammy/
Very recommended!
Alternative: code the same in Java. Take a look to ItsNat
Think in JavaScript but code the same in Java in server with the same DOM APIs, in server is way easier to manage your application without custom client/bridges because UI and data are together.
Regarding SEO, bookmarking etc in single page there are solutions, take a look to the Single Page Interface Manifesto

Web Development: Do we still need to support non-javascript users?

Background: I'm working on an e-commerce website. It was my original intention to add JavaScript on top of regular html pages, so that users with JS support got the added benefits, but users without it could still use the basic html forms to add things to their cart, to search, etc.
I've run into a few situations though, where there simply isn't a sane way to implement certain functionality in a non JavaScript way.
One example is chained attribute selects on product pages (where the color choices change based on the size chosen, because not all sizes come in every color). Even if I didn't use AJAX, it would still require JavaScript to dynamically change the options.
The only alternatives to JavaScript that I can think of would be:
A. Have an add to cart "wizard" where you have to step through each attribute choice on a separate page (yuck!)
B. Put each size/color variation out as a separate product (and force the customer to wade through the category page to find the color size combo that they want)
...And while both of the above would work regardless of whether the user has JavaScript on or not, they both punish the JavaScript users by restructuring the page and forcing them to use an interface designed for the lowest common denominator.
So the question is, since JavaScript has taken a much larger role in web development than it did a few years back, and the design pattern for an AJAX/JS application/site is so much different now than a 'classic' web design pattern, do we still go out of our way to support non JS users? Or do we say, "To hell with you! Update your browser, turn on JavaScript or go shop elsewhere"?
I'd be interested to see other developer's take on this.
I think it really depends on your target audience. I work for a company that has several types of websites, some are focused on your avg guy or gal who's into gaming. And our stats show us that the vast majority of these people have javascript enabled.
We also have a site that's focused at developers, and many of these developers won't allow javascript to run on a site unless they trust it. I've seen as many as 20-30% of the browsers on that site don't run javascript.
So it's very subjective.
IMHO, it's very reasonable to use vast amounts of tasteful javascript to enhance an otherwise mundane experience. However, I also think that when possible it should gracefully degrade. This form of degradation isn't too hard to achieve (in most cases) as long as you consider it when you're designing things.
The most important non-javascript user is Google. Do not forget that.
When it comes to things like Ajax, or any javascript for that matter, I think it's best to:
Plan for Ajax from the start; Implement Ajax at the end -Jeremy Keith
This means Intercept (hijack) links and forms using (unobtrusive) JavaScript making your code degrade well for those that don't have javascript enabled. If you want to show a fancy slider, make it a link that tells the server to show the div when you reload the page and tell your javascript to do something differently when the link is clicked.
These ideas are your safest bet for a functional, but fun website.
I think that supporting non-Javascript users is absolutely necessary for any site aiming at some kind of "normal" target group (i.e. not gamers or techies).
There is an increasing number of mobile devices accessing, and trying to parse, normal content.
Many corporate networks still block scripting for security reasons - you don't want to lose the occasional employee shopping from work, either.
Javascript tends to screw any attempt at accessibility. In my mind, creating sites that are as accessible as possible is a service to our fellow human beings.
I'm not saying I'm lily white on this. I hate replicating functionality that I just managed to achieve in my JS framework in static HTML, or making it degrade gracefully. But I think it still really, really is a must, and not merely a question of profitability. This is something worth investing a bit extra, or putting a bit of unpaid work into.
If you can exclude users that don't use javascript, so this will be some mobile devices, or the truly paranoid, as well as lynx users, and any users not using the version of javascript you write for.
If you are willing to go with that then I would suggest you have a static html page that has some message that javascript is required.
When your javascript is loaded, and the DOM tree is ready then you can replace this message, so it is never seen, with the rest of the webpage.
But, you may want to see how you can get the functionality, even if limited, for non-javascript browsers.
For example, for colors you can use a horizontal dropdown that can work on all but older IE browsers: http://www.alistapart.com/articles/horizdropdowns/
If you want to use javascript to make your life simpler then that may be a poor reason, but, if you are doing a photoshop webapp then you will need javascript.
NOTE I would suggest having it work with and without javascript, as an e-commerce site will want to not exclude any customers, I expect.
Much of it depends on your audience. As you said years ago JavaScript was used in a different way, and a bit of an annoyance even. Now with AJAX and increased functionality it's a must, and most people have it turned on.
You could say that someone with Javascript disabled is used to stuff not working pretty regularly, and a small minority.
However, if you're building a site that will be frequented by older computers or people on limited bandwidth (such as foreign traffic) you might want to consider working around them. Also a site that is heavily visited by mobile browsers might be another one to focus on.
Take a look at your analytics and see what the current usage is, and profile your audience to really find out.
The best answer will depend on a simple comparison: Estimate the extra money you will spend creating the non javascript alternative site. Estimate the money you will make selling products to your non javascript enabled customers. Compare. If you are a huge shop, then getting sales from that last 2% or 10% of users might be worth it. If you are just one guy, maybe you have more profitable ways to spend your time.
I found this interesting and fact driven post, it might help. Why we should support users without Javascript. Following is a summary:
Some people choose to turn JS off.
JS fails occasionally, HTML/CSS does not.
JS is designed to and should be the icing on the cake, not a patch-job for bad HTML/CSS.
In theory, yes; but in practice, no.
In theory it's in the spirit of the web to support hardware and software with a range of capabilities and configurations, scaling site features appropriately.
In practice, even mobile browsers are converging on the sweet spot occupied by the current major desktop browsers. Users on the outside can typically switch to an alternate browser or device in a pinch.
While it seems logical, progressive, simpler, and more efficient to require Javascript for an e-commerce site, you should ask yourself if you are willing to forego x percent of the business that would be generated by non-Javascript users, and weigh that against lower development costs.
The percent of business lost is likely not the percent of non-Javascript users, because a smaller percentage of non-Javascript visitors are likely to purchase goods are services. The percentage of lost business will probably be somewhat less than the percentage of non-Javascript users.
focus on making advanced feature to the large audience is better than spending time to find work around for non-javascript user and ones who use obsolete platform.
In my opinion there 2 things you have to consider when thinking about using JavaScript on a website:
Is Google still able to crawl all the content
If some parts of the website are not usable without JavaScript then make a very clear message for the non JavaScript users, why you site is not working for them
I think we need to support non-javascript users again.
There are users including me who doesn't disable JS for any kind of paranoia, but because some sites are so JS heavy nowadays that my browser is slowed down to a grinding halt. And this is getting worse recently, so I expect more users will do this eventually. I wanted my performance back so I installed browser plugins that let me selectively enable only the absolutely necessary scripts on the site. So I can have a dozen of tabs open again without performance problems.

Should your website work without JavaScript [duplicate]

This question already has answers here:
Do web sites really need to cater for browsers that don't have Javascript enabled? [closed]
(20 answers)
Closed 9 years ago.
We're developing a web application that is going to be used by external clients on the internet. The browsers we're required to support are IE7+ and FF3+. One of our requirements is that we use AJAX wherever possible. Given this requirement I feel that we shouldn't have to cater for users without javascript enabled, however others in the team disagree.
My question is, if, in this day and age, we should be required to cater for users that don't have javascript enabled?
Coming back more than 10 years later, it's worth noting my first two bullet points have faded to insignificance, and the situation has improved marginally for the third (accessible browsers do better) and fourth (Google runs more js) as well.
There are a lot more users on the public internet who may have trouble with javascript than you might think:
Mobile browsers (smartphones) often have very poor or buggy javascript implementations. These will often show up in statistics on the side of those that do support javascript, even though they in effect don't. This is getting better, but there are still lots of people stuck with old or slow android phones with very old versions of Chrome or bad webkit clones.
Things like NoScript are becoming more popular, so you should at least have a nice initial page for those users.
If your customer is in any way part of the U.S. Goverment, you are legally required to support screen readers, which typically don't do javascript, or don't do it well.
Search engines will, at best, only run a limited set of your javascript. You want to work well enough without javascript to allow them to still index your site.
Of course, you need to know your audience. You might be doing work for a corporate intranet where you know that everyone has javascript (though even here I'd argue there's a growing trend where these sites are made available to teleworkers with unknown/unrestricted browsers). Or you might be building an app for the blind community where no one has it. In the case of the public internet, you can typically figure about 95% of your users will support it in some fashion (source cited by someone else in one of the links below). That number sounds pretty high, but it can be misleading; turn it around, and if you don't support javascript you're turning away 1 visitor in 20.
See these:
https://stackoverflow.com/questions/121108/how-many-people-disable-javascript
https://stackoverflow.com/questions/822872/do-web-sites-really-need-to-cater-for-browsers-that-dont-have-javascript-enabled>
You should weigh the options and ask yourself:
1) what percentage of users will have javascript turned off. (according to this site, only 5% of the world has it turned off or not available.)
2) will those users be willing to turn it on
3) of those that aren't willing to turn it on, or switch to another browser or device that has javascript enabled, is the lost revenue more than the effort to build a separate non-javascript version?
Instinctively, I say most times the answer is no, don't waste the time building two sites.
My question is, if, in this day and age, we should be required to cater for users that don't have javascript enabled?
Yes, definitely, if the AJAX functionality is core to the working of your site. If you don't, you are effectively denying users who don't have Javascript enabled access to your website, and although this is a rather small proportion (<5% I believe), it means that they won't be able to use your site at all, because the core functions are not available to them.
Of course if you're doing more trivial things with AJAX that just enhance the user experience but are not actually central to the core functionality of the site, then this probably isn't necessary.
Depends really.
I personally switch off JavaScript all the time because I don't trust lots of sites.
However, since you users have explicitly asked for your application, you can assume they will trust it and there is no point in doing extra work.
More, if you have that strong AJAX-affinity requirement, the question seems odd enough.
This is a bit like beating a dead horse, but I'll have a go at it, sure.
I think there could be two basic approaches to this:
1.
Using ajax (and, basically,
javascript) to enhance the experience
of the users, while making sure, that
all of the application's features
work without javascript.
When I am
following this principle, I develop the
interface in two phases - first
without considering javascript at all
(say, using a framework, that doesn't
know about javascript) and then
augment certain workflows by adding
ajax-y validation (don't like pure js
validation, sorry) and so on.
This means, if the user has javascript disabled, your app shall in no way break or become unusable for him.
2.
Using javascript to its fullest, "no javascript - no go" style. If javascript is not available, the user will not be able to use your application at all. It is important to note, that, in my opinion, there is no middle ground, - if you are trying to be in both worlds at once, you are doing too much extra work. Removing the constraints of supporting no-javascript users, obviously adds more opportunities to create a richer user experience. And it makes creating that experience much easier.
I think that depends on the type of web application you are going to build. For example in an e-commerce application the checkout process should propably work without java script because there are some people who deactivate js for checking out (in our experience). In a web 2.0 application in my opinion it isn't necessary to support non-js browser experience.
Developing for both also complicates the development process and is more cost intensive. you have double your web test efforts (testing with and without js) and also think different in the planning phase.
I think it depends on the market segment you're aiming for, if you're going for a tech crowd -such as Stackoverflow.com, or perhaps slashdot- then you're probably fine in expecting users to have JS installed and active.
Other sites, with a medially tech-aware audience, may suffer from users knowing enough about JS-based exploits to have deactivated JS, but with not enough knowledge to enable Scriptblock (or other browser-equivalent).
The non-tech aware audience are probably with the tech-crowd, since they possibly just don't know how to disable JS -or why they may want to- regardless of the risk.
In short, you should cater to spiders without JavaScript enabled, but only to the degree necessary to index the data that you want to expose to the public. Your browser requirements of IE7+ and FF3+ exclude far more people than the total number of people who disable JavaScript. And of those who do disable it, the vast majority know how to enable it when necessary.
I asked myself the same question the other day and came up with the answer that in order to use my application one must have Javascript enabled. I also checked various Ajax powered sites. Even Stackoverflow.
But considering this fact I also believe that you do need to support some degree of prehistoric applications. The main idea is to not let application break when users don't have enabled Javascript. Application should still display relevant data, but its functionality would be limited.
To add to some of the old discussion on this page. Google is now searching JavaScript: http://www.i-programmer.info/news/81-web-general/4248-google-now-searches-javascript.html
This is an issue that I was thinking about just a few days ago. Here is some information
In Google Chrome there is no way (menu/option) inside the browser to turn off Javascript.
Many websites including those from leading names like Google, etc., will not work without Javascript.
According to stats over 95% of visitors have Javascript enabled now.
These stats made me think. Do I have to break my back writing a lot of background code and everything for users who have disabled Javascript?
My conclusion was this. Yes, I have to include Javascript support, but not at the cost of sanity. I.e. I can afford to give it a low priority.
So I am going to have support for non-javascript browsing, but I will build most of it after my site is deployed.

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