I have a search engine which is implemented in Java. It's very complicated. I want to use a dynamic interface for the client so I guess I should go with AJAX. I absolutely don't know NOTHING about PHP, nor AJAX and this is my first web project but I have to do it ASAP and I'm seeking to learn how to do it as fast as possible. I want my page to send the query to the Java engine, and after processing the Java code should return the result to the page.
Thank you for your help.
GWT (Google Web Toolkit) is probably the fastest way for a non-UI Java guy to build a complex, ajax-enabled, dynamic UI.
As it seems you are already familiar with Java, why don't you use Java Server Pages (JSP) to build the web project? Here is a guide to getting up and running.
Related
I'm pretty new to web development, so I had some basic questions to get me pointed in the right direction.
For the last week I've been learning the rails framework, and from what I understand, this framework is great for building a website, but you still need javascript to build nice front-end interface/apps that run in the browser. Is this understanding correct? If not, why does javascript appear to be so essential to almost al websites? In other words, what can you do with js?
Also, I was wondering if it is necessary for me to learn javascript now that there are tools like GWT that compile Java into js. I ask because, I am proficient in Java but have no knowledge when it comes to javascript. How far can GWT take me before I need to learn javascript, or do I have to learn javascript at all?
If someone could point me int he right direction by answering these questions, I'd be very grateful.
Thanks
GWT compiles Java to JavaScript, but you still will need to learn about web development.
I have seen many projects going wrong with GWT because people just started writing Java code and did not care about the underlying platform (the browser) at all.
If you don`t want to care about the browser use some plugin technology (if you are an app inside a controlled environment), otherwise first learn about how to build apps with HTML + JS + CSS.
Eventually you will discover that GWT is a great toolkit for writing fast JavaScript apps in Java, that packs many best practices for building web apps inside the toolkit. It has good abstractions, but every abstractions leaks so you will need to have good knowledge of the browser. You will save on things like keeping away from the bad parts of JavaScript.
I'm working with GWT now, and I haven't had to use Javascript at all yet. I'd say for most websites, GWT should be fine.
I want to create an application that submits same/similar data to sites containing web forms. These sites use PHP scripts...
I have a php script with me, that submits data in the manner that i require, to such forms. What I want to do is, design an entire web app around this code... I tried to obtain equivalent java code that does what the php code is doing, but could not obtain such code...
Since Google App Engine supports Quercus framework for PHP, what I am thinking now is, use the PHP code for actual submission of forms to their actions, and rest of application (that tracks all submissions and does other stuff like login/logout...) is in Java.
This would require some method by which I can pass the relevant form parameters from Java code to the PHP script, then some way for the php script to return the response of each submission back to the java code.
Is such an application doable? Pls keep in mind that I want to use Google App Engine for this purpose.
Nowadays it is possible to use different languages in different modules of the same app.
See Using both Java and Python with the new "Module" feature on AppEngine?
It should be doable with Quercus. We deploy a Python app that has some Java/Clojure backend processors but both languages are "native" to GAE. Using PHP will be a serious pain and not worth it all. I suggest that you just learn Python you will master it faster than using Quercus on GAE.
If you also go after PHP you stick to your LAMP knowledge. I suggest thay you do now!
Disclaimer: I wanted to use JRuby on AppEngine but I had a lot of difficulties (plus you have to know how everything works optimally on GAE) so I took up Python
I want to make cross - platform app which could be used for different smart-phones, and been advised to make 'Web App'.
Can 'web app' work without internet?
How to do it, which programing language to use?
thanks
Oh sure. Bundle all your HTML, JS anc CSS with your app, and have a thin Java/Android app over these assets. If you are not making any calls to fetch or show external HTML/pages, you don't need internet.
Most likely no.
While it is possible to run "web apps" without access to the internet (you can simply execute Javascript locally from some browsers), it would be
(Subjectively) not particularly useful.
Not supported by many devices, whom (like the iPhone) do not allow the storage and execution of arbitrary, non-native code on the device.
However, some frameworks do exist that hold the idea of "web apps" can be a distribution model. For example, PhoneGap allows you to code in HTML5/Javascript, and distribute your app to multiple platforms.
Yes, it can work offline once downloaded from web. Use just any regular programming language for web application development. If you are good at programming, I recommend ruby-on-rails or ASP.NET MVC with Jquery mobile.
You might want to look into frameworks like:
PhoneGap: http://www.phonegap.com/
jQuery Mobile: http://jquerymobile.com/
GWT Mobile: http://code.google.com/p/gwt-mobile-webkit/
Your question is very broad so it's hard to give a useful answer. Essentially when making a web app you'll normally be working with javascript, css, and html... though there are frameworks which will let you write your app in Java/Python/Ruby and then have those languages create your app for you. Keep in mind this is mostly all front facing stuff though. The actual web app will still need to have a backend written in a programming language that you understand (hopefully).
Good luck :).
Check out the jQuery Mobile API - I started using it recently and it has proved to be a viable option. Check this out.
https://developer.mozilla.org/en/Using_Application_Cache with an application cache your Web App can be used offline. It will cache the resources you specify to disk.
So you can write a Javascript + HTML webpage/app and use it both on and off line.
You can cache/store:
HTML
CSS
Javascript
Images
GET Requests
I have just been looking at the GWT and i am impressed by what i have seen but i do not really understand how it is used to when creating web applications.
For example, when im programming in PHP or JSP creating a simple app that lets users register, adds the detailes to a database and then allows them to login is pretty simple but i was wondering how GWT does this?
When doing this in GWT, would GWT widgets be used to construct a frontend(client) that accepts user input and then sends it to a server which is written using pure Java, the Java then does all of the data processing and database interfacing?
If my understanding is correct, is GWT just a way to write javascript frontends in an easier way?
Have you looked into the GWT Overview? I think this line explains it the best:
The GWT SDK contains the Java API
libraries, compiler, and development
server. It lets you to write
client-side applications in Java and
deploy them as JavaScript.
Basically, you write your code in Java, all the while using the GWT to create complex UI's, etc. When you "compile" it, it is highly optimized JavaScript that translates well to multiple browsers, including web platforms.
Whatever language you want to use server-side does not matter - ASP.NET, PHP, etc - it will all work with GWT because GWT is, ultimately, JavaScript.
Basically, Google is trying to make it simple to develop web applications in a familiar language, and doing all the underlying work for you. I'm sure there is someone else who can further expand on the capabilities and advantages of GWT, but I hope this helps!
Exactly. "In the end, it's just JavaScript", you can "Use the backend language of your choice"
Coming from PHP with some Java Struts 2.0 experience any tips/tricks on learning GWT? I have been looking at some tutorials but just wanted to know if anyone has some great gems to pass along?
As someone that has done PHP, Struts2 and GWT, a good tips from me for someone that is coming from web framework like Struts2.0/PHP would be:
Throw away the old mindset, the mindset that a web framework works in request-response way. That's not how GWT works. GWT is a full ajax framework. Get a good understanding of AJAX and throw away those old mindset to get a good grasps of GWT.
Think in application development and not website development. That would affect the way you build navigation in your application with GWT.
You are not building hyperlinks to navigate between html pages, but you are using an event listener to update a partial content in your application. Get a good understanding of this.
With that in mind, always remember that you are not throwing back full html pages, but just updating a partial content in your application
Get a good understanding of Java anonymous class and inner class because you will use this alot in GWT. This is something that is used rarely if you are building with Struts2.0
The last tips would be to learn how to organize your code. If you can do it from beginning, please do so. Because you can write everything in one class if you want to. A good tip would be to take a look at this video on best practice on GWT.
Nothing beats Google's GWT quickstart (IMO):
http://code.google.com/webtoolkit/gettingstarted.html
I agree with karim79. Also add this to your list: http://examples.roughian.com/
GWT developers still need good HTML and CSS skills. It is sometimes useful to build up chunks of HTML on the client or server side (performance, skinning etc.) and not build every part of your GUI using GWT Widget trees in Java code.
Our framework (GWT Portlets) will help you structure your application. It includes a simple demo application in its own directory that you can copy to start a project.