possible pattern for validation of page

[ryanferretti@gmail.com]

Hello, I have to validate a form with a lot of fields and was wondering
if there was a better way to do this rather than just a long list of
"if" statements. Would it be better to use a strategy for this to
separate the code. Any suggestions for other ways?
Thanks

[pven]

Hi,

I am not able to suggest a pattern, however I found the
apache struts framework very modular for validation and error handling.


To just give a breif overview of struts, (just in case you
are not aware of struts)...

In struts, for every page we define a class that will hold
all the fields in the page.

Lets say the page has an input field called "name".
In sruts, we will have a class for that page

class Page extends ...{

string name ;

void setName (String name ) {

}

string getName() {
return name ;
}

}

When the form is posted, the struts engine creates
an object of this class Page and pushes the value provided
in the field name to the member variable name by calling the setName().

This Page object also has a method called validate()
where we can write the code to check if the fields in
the form are of the right type. Again, there would be if else...
This validate() method is automatically called by the struts engine...

If there are errors in validation, struts has a neat way to throw
the error back in an elagant manner.. ( error message is read from
an message file)

Back,

I don't think this is the appropriate answer to your query
but I found the struts framework very neat when building jsp pages.

Previously, I had the validation and business logic in the jsp,
and when there was a requirement change I needed to go through
a lot of pain to understand the flow in a jsp that was packed with
everything but with struts things became simpler....

Prasanth

[ryanferretti@gmail.com]

Thanks for the reply, I have had experience with using struts and had
considered it with for this project. We decided on using Sping MVC
instead of struts because of what it offers.

Ryan