Re: Netbeans/Hidden field question

> Rick Fincher wrote:
>> Hi Neil,
>>
>> No problem on the help.  Figuring this stuff out cost me many
>> handfuls of hair!
> Rick,
>
> That's great - I don't have much hair left to pull out, so my wife
> says thank you! :)
> I missed the hidden field in the palette yesterday (no pun
> intended...) - I will give that a try and see what happens... And I'm
> just getting started with javascript - I've been writing java code for
> 10 years (and C/C++ for more than 30...) but I've only been doing web
> related java for a couple of years now - so this is fairly new for me.
>
> As I said yesterday, I had to return to Netbeans 6.0.1 because it
> seems that 6.1 was not actually creating java code for ANY of the
> palette items I created - buttons, text fields - nothing. My project
> was originally created in 6.0.1 and seemed to compile fine with 6.1,
> and I could add new items to the screen in 6.1 but I was unable to
> modify them in the code because they were not defined - very strange.
> So for now, I'm back to 6.0.1 and once I get this javascript stuff
> figured out, I'll try 6.1 again and see what happens there - maybe I
> did something dumb....

>
> Thanks for the help - If I get stuck again I'll let you know...
>
> nbc
>
>>
>> A hidden field is a special type of text field in HTML. The component
>> palette has it in there below the password field.  It acts just like
>> a text field, but it is always invisible on the screen.  JSF saves
>> the contents of all the screen controls and restores them if the page
>> is redrawn (as happens when a submit button action returns a null).
>>
>> If you use a regular text field and make it invisible, its contents
>> don't get sent forward when the page redraws.
>>
>> To access a hidden field called hiddenFieldWeight in Java use:  
>> hiddenFieldWeight.getValue()
>>
>> To access it in Javascript in your onClick() or onLoad() (only in the
>> body component) use:
>>
>> document.getElementById("form1:hiddenFieldWeight_field").value
>>
>> Notice there is a "_field" added to the end of the name.  JSF does
>> that internally to help keep things straight.
>>
>> You won't see that on the JSP page, you have to look for it in the
>> browser.  When your page gets drawn, use the "view source" of the
>> browser to see the actual HTML code that JSF generates for the page.  
>> If you are unsure of what the components name gets set to, just
>> search for the name you gave it in the visual editor.  The component
>> will always start with that name followed by an underscore and some
>> description like "_field" or "_dropdown".
>>
>> Another thing that is handy to know is the "isPostBack()" method.  
>> You can call it with or without the "this" as in
>> "this.isPostBack()".  I always forget the name of it so typing this
>> with a dot brings up all the page stuff.
>>
>> The isPostBack() method returns false the first time a page is drawn
>> and true each time a submit call re-renders it after that.
>>
>> The preprocess() method on the page only gets called on a postback,
>> never on the initial rendering of the page, so it is handy too.
>>
>> The neat thing about using Javascript for this is the speed.  You
>> don't get the 3-5 second delay while the page gets submitted.  Ajax
>> would work for this too but there is still going to be some time lag.
>>
>> Basically, you just put a Javascript in the onChange() Javascriptof
>> each component that you want to be sure is saved.  The Javascript
>> stuff a value in the hidden field to flag a change.
>>
>> The Javascript will show up in the JSP page automatically.
>>
>> I tend to think in terms of Java, so sometimes the Javascript stuff
>> confuses me because I don't see it in the Java code.  I guess its
>> part of the "View" in the "Model-View-Controller" design pattern,  
>> but it actually affects the logic of the program, not just how it looks.
>>
>> So, if you like you can set the script from Java.  You do this with
>> the "setValueBinding()" method of the component.  With that you can
>> set any of a components properties that show up in the parameters
>> window when you click on a component.
>>
>> Say you want to change the text in a button, called button1, under
>> program control.  You would use:
>>
>> button1.setValueBinding("text",
>> getApplication().createValueBinding("New Button Text"));
>>
>> To set the onLoad() Javascript of the body it would be something like:
>>
>> String confirmScript = "confirm(\"Are you sure? Unsaved changes!\");
>> body1.setValueBinding("onLoad",
>> getApplication().createValueBinding(confirmScript));
>>
>> I'm not actually sure about escaping the quoting in the string, you
>> may have to use """ instead of  \".
>>
>> You can also use page parameters with their script language
>> identifiers.  This is nice if you want to use stuff looked up from a
>> database to set the values.  Some examples with a hyperlink are:
>>
>> hyperlinkCert.setValueBinding("visible",
>> getApplication().createValueBinding("#{page1.certIconVisible}"));
>> hyperlinkCert.setValueBinding("target",
>> getApplication().createValueBinding("#{page1.blankValueBinding}"));
>> hyperlinkCert.setValueBinding("url",
>> getApplication().createValueBinding("#{page1.viewCertURL}"));
>> hyperlinkCert.setValueBinding("style",
>> getApplication().createValueBinding("#{page1.certUrlStyle}"));
>>
>> Hope this helps!
>>
>> Rick
>>
>>
>> Neil B. Cohen wrote:
>>> Morning Rick,
>>>
>>> I had asked about using AJAX with Netbeans and you sent me a
>>> suggestion (at home - nbc@...) regarding using a hidden
>>> field and javascript to decide whether or not to put up a
>>> confirmation dialog. I was looking at how to implement that this
>>> morning, and I'm a bit confused...
>>>
>>> I can create a static text field and make it 'hidden' on my web
>>> page. But in my java code, it doesn't show up as a member variable
>>> anywhere - it is only an element in the jsp code itself.  How do I
>>> access that element from within my java code to change the text from
>>> 'clean' to 'dirty' or whatever... I feel like I'm missing something
>>> simple here but I'm not sure what it is...
>>>
>>> If I figure it out I'll let you know... Sorry to bother you with
>>> this, but I like your suggestion - I think it will work if I can put
>>> all the pieces together,
>>>
>>> Question - is this a problem with Netbeans 6.1?? (I just installed
>>> 6.1 yesterday). I just created a text field and it doesn't seem to
>>> create a corresponding object in the java code... There is nothing
>>> in the init() routine.... Should I be switching back to 6.0.1??
>>>
>>>
>>> thanks,
>>>
>>> nbc
>>>
>>> NAME:   Neil B. Cohen (Verisign Inc.)
>>> PHONE:  703-948-4471
>>> DOMAIN: ncohen@...
>>> *************************************************************
>>> * Murphy's Philosophy: Smile - tomorrow will be worse...
>>> *
>>> * O'Tooles Commentary: Murphy was an optimist!
>>> *************************************************************
>>
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@...
> For additional commands, e-mail: users-help@...
>