Use AJAX instead of TagLib?

I was thinking about the idea of using Ajax instead of TagLib. The most elegant way would be: Using Java Annotation. The idea is, designers or anybody can make the HTML without any taglib ,just using the "standard" HTML tags with id or name, and call the Javascript. That way any WYSIWYG can be used, developer don't have to care about HTML format or the way it's designed. In many (at least open-source) WYSIWYG don't show the taglibs in that final result (or have a template of it), so it's hard to "preview". Other reason is, developer should know Java and HTML/TagLibs should not be a must-have, since we got CSS and AJAX.

It should work just like that:

MyClass.java:

import ...

// Use the ResourceBundle resource[.{Locale}].properties
@Jay2JI18n(resourceBundle="org.format.resource",name="MyClassForm")
public class MyClass {
    private Integer age;
    private String name
    private Date dob;
    private salary;

    @Jay2JLabel(resource="label.name")
    @Jay2JMaxLength(value=50,required=true,)
    @Jay2JException(resource="exception.message")
    public String getName() {
         ...
    }
    public void setName(String name) {
        if ( name.trim().equal("") ) {
            throw new Exception("Name is required");
        }
    }
    /* Getter and setter for age */
    ...
    @Jay2JLabel(message="Salary")
    @Jay2JFormat(format="##,###.00",language="en")
    @Jay2JFormat(format="##.###,00",language="pt_BR")
    // or you could use that to access a property of the ResourceBundle
    //@Jay2I18nResource(resource="money.format")
    public Date getSalary() {
        ...
    }
    /* Setter for salary and getter/setter for the rest */
    ...
}

Page.html:

<html>
  <head>
    <SCRIPT>
    </SCRIPT>
  </head>
  <body>
     <form onload="Jay2J.formalize(this)">
     </form>
  </body>
</html>

of it can be a HTML with the fields filled; PageWithFields.html:

<html>
  <head>
    <SCRIPT>
    </SCRIPT>
  </head>
  <body>
     <form action="myfavoritewaytopostthis" onsubmit="return Jay2J.validate(this)" onload="Jay2J.formalizeExistField(this)">
       <label>Name</label><input type="text" name="name" id="name" />
       <label>DOB</label><input type="text" name="dateOfBirth" id="dob" />
       <label>Salary</label><input type="text" name="salary" id="salary" />
       <input type="submit" />
     </form>
  </body>
</html>

That way the Annotation (no XML, it's like HTML in the way that it's only another file modify and XML is not Java) will define how the HTML will be treated. That way developer can stop developing in HTML and use just JAVA (or JavaScript), do you think that's a valid idea?

Asked by: Lily675 | Posted: 28-01-2022

Answer 1

When i see your topic title i thought:

You cant use Ajax in stead of a taglib. AJAX is javascript on the client and the taglib is java code on the server.

After reading your post i thought, ah he whats to do what [link text][1] does

But then not entrily the same.

[1]: http://code.google.com/webtoolkit/ GWT

Answered by: Melanie418 | Posted: 01-03-2022

Answer 2

First impression is ... yuck, someone who picks this up will have no idea what they're looking at without learning your (new, different, non-standard) way of doing things. You could do something similar by implementing a tag that takes a bean (value object) and maybe does some minor reflection/annotation inspection to emit the proper html, and you'll save yourself a lot of heartache down the line.

Make your value objects implement a simple interface that your tag will use to extract and format the html, and you can probably get 80-90% of where you're trying to go with 1/2 the work or less.

Answered by: Miller728 | Posted: 01-03-2022

Answer 3

First impression was, WTF. After reading further, I get a impression that you are trying to address the 'separation of concerns'problem in a different way. Some observations on your approach.

Requires client side scripting to be enabled and hence fails accessibility guide lines.
Reinventing the wheel: Many web frameworks like Tapestry, Wicket try to address these issues and have done a commendable work.
On your comment on binding Java to HTML, the code example doesn't convey the idea very clearly. formalize() seems to create the UI, that implies you have UI (HTML) coded into java (Bad Idea? probably not NakedObjects attempts to you domain models for UI, probably yes if one were to write a page specific code)
validate() is invoked on onSubmit(), Why would I want it to be processed asynchronously!! That aside, using obstrusive java script is way out of fashion (seperation of concerns again)
Your argument on taglibs preventing WYSIWIG, though justifiable, is not entirely valid. Tags cannot be used to compose other tags, each tag is a unique entity that either deals with behaviour or emits some html code. Your argument is valid for the second case. However, if I understand your formalize() correctly, you are doing the same!

Nice to hear some new ideas and Welcome to SO. Also, please use the edit question option until you earn enough reputation to add comments. Adding answers is not the right way!

Answered by: Melissa692 | Posted: 01-03-2022

Answer 4

This idea has some merit, if I understand it correctly.

You could use AOP to modify a servlet that would actually be called for the page. The servlet would then return the html, using the annotations.

This way the programmers don't see the html generation, and if you have a standard javascript library for it, then it may work.

But, just because it works doesn't mean that you should do it.

As was mentioned, there are many frameworks out there that can hide the javascript from programmers, such as JSF, which is basically taglibs and a different navigation scheme.

I remember using the beehive project to do something similar, it was annotation driven so I could basically do everything in java and it generated the javascript, years ago. :)

Answered by: Aston166 | Posted: 01-03-2022

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