JSP/.NET XML - simple client to display html - html

I am fairly proficient in PHP, but just starting out in ASP.Net and JSP/Java
I would like to learn JSP/ASP.NET XML to HTML transformation with some simple practical examples. Im not looking to learn how to edit XML, just displaying it, but im having trouble finding definitive examples/tutorials.
Ive spent quite a while studying JSP/ASP.NET but quickly find how vast they are and how many different ways there are to do this (quite frankly im a bit overwhelmed). I would be really grateful for advice before I embark upon this journey (and perhaps I will be saved from going in the completely wrong direction). If there are any tutorials or especially example apps you could point me towards this would really help (i like to do hands on learning)
For this I expect I need to do the following:
1) Set up a server for each technology (im using Tomcat and IIS at the moment - are these the best?)
2) Use some parameter based routing system (MVC?, but this is most surely overkill for me)
3) Parse the XML and create some variables/objects
4) Display the HTML (Use template libraries (JSTL? not sure for ASP.NET))
Any tutorials/example apps you could point me towards to help me through the above steps will be truly appreciated.
Thankyou
Ke

By the sounds of your skillset, carefully working through this developerworks tutorial on JSTL looks like a good place for you to start. It does cover the XML handling libs around part 4, and it'll also help you avoid the mistake of using scriptlets where JSTL would give cleaner, less error-prone and much more readable code.
You'll also most likely want IDE support, so that you get documentation, syntax checking and autocomplete. I personally use Eclipse (The EE download will have everything you need and more) but NetBeans might be the most straightforward to get your started.
Tomcat will be fine to get you started, but these IDEs tend to have build in web containers to save you time in deploying and testing.

Related

Login/Registration using scala

Just wondering if when creating a login/registration web page using scala is very similar when doing with PHP/HTML which I have used in the past. I've just decided to start learning scala and am a total beginner with no clue. With PHP/HTML, I would use a form, 'POST' method and then the appropriate my_sqli prepared statement insertion and selections. Is it similar or very different in terms of overall methods and way about going with it (obviously excluding the minor differences in syntax). How and in what ways is it different or similar? thnx
Scala is totally different from PHP. Finding connections between them is really hard. I would say that Scala is better in every way but bashing PHP is just too easy nowadays.
I would suggest you to give a look at Scalatra, arguably the most mature among simple web frameworks in Scala. Every framework works differently but you can get an idea of how you think and write code in Scala giving a look at Scalatra examples.
Also, if you never worked on a JVM, it will take a while before being able to properly develop logic in your code. There are many things to learn about the environment (and obviously about the language too) before being able to develop a web app. My suggestion is to first spend some time studying the language and only then begin approaching web development. If you need a language that you can pick up and start writing code, Scala is not the right choice.

Creating a language on the Rubinius VM

I'm looking to play around with the Rubinius VM to create a langauage, but just reading the documentation, I'm still quite lost on how to get started. Even looking at the projects, I still can't seem to figure out where the parsing and using the vm comes into place. Does anyone have any resources for this?
Hey I'm a contributor to the Fancy language that runs on rubinius. If you're interested in parsing take a look at boot/rbx-compiler there you'll find a Parser (implemented with KPEG) that basically constructs a tree of AST nodes, each of those nodes has a bytecode method that produces the rubinius vm instructions for everything to work. Fancy share a lot of semantics with ruby, so I guess starting with it would be easy if you're already familiar with ruby. You'll just need to checkout the examples/ dir to geet a feeling on the language and then the kpeg parser, ast nodes, loader, as you progress exploring the compiler. These days Fancy is bootstrapped (that means that the compiler has been written in fancy itself - at lib/compiler) but rbx-compiler is the first step in that process.
Hope exploring Fancy's source code can be of help to you.
In case you hadn't seen it, check out Evan's keynote from 2011 LA Ruby Conf. He shows how to build a simple language, which might be helpful.

Why use HTML markup in languages like ruby, php, asp.net mvc instead of XLST to convert XML to HTML?

I just learned about XLST on stackoverflow today (I love how in computers you can program for years and constantly have 'darn, how did I not know about that technology' moments). I'm wondering how popular XLST it is for web development? I've worked on a few websites (using php, ruby, and asp.net mvc) but I'm not a web developer by any means.
Is the reason each web language I listed above has it's own way of marking up html (and thus taking advantage of 'templates') just to make it simpler (simpler as in more to the point and not and more geared to one specific purpose) in that you don't have to first convert what you want to display to xml and then to html? Or are there other reasons why XLST doesn't seem too popular for web development? Or am I just crazy (again most of my work is with Desktop apps) and actually it is widely used in webpages? If not in development, what do you mainly use it for?
It seems that being able to easily serialize objects in xml with C# would make XLST a very popular way of displaying object in HTML on websites?
Thanks for feeding my curiosity!!
IMHO there are two main reasons why XSLT is not very popular:
it's generally hard.
you can just skip it and directly write HTML, and HTML is not hard and has first-class support from all web frameworks.
In summary, there is usually not enough reason to introduce yet-another-abstraction. Abstractions are not free, they solve some problems but introduce others (i.e. the "solve it by adding another layer of indirection" adagio), so the benefits must clearly outweight the costs.
That said, there are XSLT-based solutions for many web frameworks, e.g.:
ASP.NET MVC XSLT view engine
libxslt in RoR
Here's an excellent article that discusses XSLT for view engines.
As I've started so many answers on Stackoverflow, it depends :)
Doing what you're describing is adding another layer of abstraction between application logic and the display output; and introducing another language. There can be very compelling reasons to do this, but the important part to keep in mind is that you need to recognize and quantify the need to be able to understand whether it's worth it.
It seems that being able to easily...
As with most things in software development, something that seems easy after a few hours of pondering turns out to be quite complex and involved when you actually try to do it. This is especially true here, because I have built exactly what you're describing in ASP.NET. It provides a very interesting mechanism for skinning sites, as you simply have to define your model XML schemas and anyone can write an XSLT to transform it. But XSLT is like a one-way tunnel. It can't (easily) reach back out or to the sides to pull in extra info that wasn't included in the original model - "peripheral data", so to speak. In fact, it has a hard time really being aware of what's going on in the application at all.
Also, XSLT is very verbose, and (in many ways) a crude language. This makes it... unpleasant to do things like loops, and rather time consuming to even do something like an if-else statement*. An XSLT that generated something like, say, the page you're looking out right now would probably be several thousand lines long - which you're adding on top of the application code you have to write either way.
It is simply an additional cost which may or may not be worth it, depending on what you're trying to accomplish.
*For example, I once saw a developer try to write a pager control (e.g. "first | prev | 1 | 2 | 3 | next | last") in XSLT. We still visit her in the sanitarium from time to time.
XSLT is not popular in web frameworks because XML is not popular in web frameworks. But, if you have XML data, or you are willing to convert your objects to XML then XSLT is the best tool for transforming that XML into HTML or XHTML.
If you are using ASP.NET checkout myxsl
When I first discovered XSLT I was excited because I could write semantically correct presentation markup, and I would no longer have to write so many hacks and use so many nested layers of <divs> just to get the effect I wanted -- XSLT could do all that for me!
Then I realized XSLT was a weird, backwards, and painful language to write in. I believe other web developers have discovered the same thing and steered away from it.
What's the point when you can just write straight HTML and avoid an extra layer of abstraction? And if your application is complex enough to warrant that, then there are so many better, simpler, more powerful alternatives (other templating languages).
The design of a web page is often handed over to designers.
One thing about web designers is they know HTML (if you're lucky) but they're not going to know XSLT.
It's unpleasant to do loops and if-else-statements in XSLT like it's unpleasant to hammer with a screwdriver. Don't do that. The behaviour of an XSLT script is driven by the data, you only need to find the right matches for your templates. XSLT-templates are not just a piece of code. The actual data from the XML-file fitting in the "match"-attribute of the "template"-elements decide if and when to execute a template.
Once you discover that XSLT works different to other languages you see the possibilities this gives to you. It's easy to do things that are hard to do in usual languages. Just use it when appropriate. If your data comes as XML and you know XSLT and XPath, this is the right tool to build web pages.
Hints are available at e.g. jenitennison.com/xslt.

Essential Dojo

I'm starting to use Dojo; this is (essentially) my introduction to AJAX. We have a Java backend (torque / turbine / velocity) and are using the jabsorb JSON-RPC library to bridge Java and Javascript.
What do I need to know? What is the big picture of Dojo and JSON, and what are the nasty little details that will catch me up? What did you spend a couple of days tracking down, when you started with Dojo, that you now take for granted? Thanks for any and all tips.
The first thing to do is get familiar with the Dojo Object Model. JavaScript does not have a class system so the Dojo toolkit has created a sort of "by convention" object model that works rather well but is very different to how it works in Java for example.
The reason I suggest getting familiar with it is so you can dig into the code base whenever you start experiencing issues. The documentation available has improved significantly over the past year, but every now and then I find myself having to work out a bug in my code by learning exactly how the Dojo code involved works.
Another tip is to make use of the custom build feature which will significantly improve performance once your application is ready.
As a general tip on DHTML programming, use firebug (a plug-in for Firefox). It allows JavaScript debugging, DOM inspection, HTML editing in real-time and a whole lot more. I've become totally reliant on it now when I'm working in DHTML!
Good luck!
I too just dove head first into Dojo, they have a good API documentation at http://api.dojotoolkit.org/. Even Dojo Campus has some good examples of the plug ins.
If you ask me O'Reilly's Dojo: The Definitive Guide is the best Dojo book on the market.
I also would like any tips and pointers from the Dojo masters.
Cheers
Make sure documentation you read pertains to as recent a release as possible, since a lot has changed very quickly in the Dojo architecture.
Also a great way to see how some Dojo or Dijit widget is used is to look at the source code for the tests - for example, the DataGrid has poor documentation but the tests show a lot of use cases and configurations.
Sitepen is a good resource for Dojo articles.
Also, read up on Deferred (andDeferredList), as well as hitch() - two extremely flexible and powerful features of Dojo. SitePen has a great article on demystifying Deferreds.
Check out plugd, a collection of Dojo extensions that make some things more convenient or adds some clever functionalities to the language. It's made by one of the core Dojo authors so it's rather reliable. It even brings some jQuery niceties into the framework.
Some more things: look into data stores, they're very useful and a much cleaner way to handle Ajax. DojoX has a lot of nice ones too, just remember that DojoX ranges in how well documented or how experimental the components are. Learn the differences between dojo.byId and dijit.byId, as well as the HTML attributes id versus jsId (again, Sitepen has an article).
A couple of things that caught me when I started writing widgets where:
[Understand what dojoAttachPoint, dojoAttachEvent, containerNode and widgitsInTemplate do][1]
have a firm grasp of closures,
Get your head around deferreds
understand ItemFileReadStore, ItemFileWriteStore and stores in general
You can look at stores like a ResultSet (sort of) as well you can data bind them to widgets.
With these major concepts you can start to put together some compelling applications.
Generally what I do is I build a JavaScript facade around my service calls and then I will scrub the response into a store by attaching the first callback in the facade, that call back converts the results into a store and then returns it. This allows me to not hard bind my services to Dojo constructs (so I can support mobile, etc.) while also retuning the data from the facade in a format that data aware widgets expect.
As well if you are doing Java service development you my want to look into JAX-RS. I started out using JSON-RPC which became JABS-ORB but after working with JAX-RS I prefer it, as it integrates well with JPA-EJB and JAXB.
First read how to configure Dojo in your application. Try to understand basic structure of Dojo like if we are writing dijit.form.Button or dijit/form/Button it means Button.js resides in dijit/form folder. Try to understand require, define, declare modules of Dojo. This is enough to start Dojo Toolkit.
Very important fact, indulge with your own sample project using Dojo.

Is "include file" in shtml the best method to keep non-database changing data

We have a website that uses #include file command to roll info into some web pages. The authors can access the text files to update things like the occasional class or contact information for the department.
My question is this, I don't see anyone using this method and wonder if it is a good idea to keep using it. If not, what method should I transition to instead?
I don't think there is anything wrong with it, and I've done some similar things with PHP. If the people that make the changes are comfortable with how they do it and they can do what they need to, I think you should stick with it. There could be some retraining involved and/or a fair amount of work involved for changing the system.
If you are using ASP.NET then you could bundle that code into a nice little UserControl that will display all of the important information.
Other platforms should allow you to bundle the logic into a class object, and display it using that.
It really depends on the platform that you are using to deploy the application in. The include file could be your best solution if you are deploying in a more limited platform.