Re: DynaValidatorForm 'forgets' request-attribute on redisplay after validation
At 11:31 AM + 11/24/04, Adam Hardy wrote: On 11/23/2004 02:20 PM Joe Germuska wrote: Your action isn't executed if validation fails. However, the validation is performed on a second request, so the object placed into the scope before the form was presented is no longer there. If your categories are really relatively static, consider managing them in Application scope rather than request. I often have one or more plugins which initialize common menus like states and provinces or months of the year and place them into the application scope (I like to use the DigestingPlugIn). Your code doesn't look like there's anything particularly request-sensitive about the category tree. Some people make lists a property of the form itself. This is also one of the core use cases for some kind of view controller registered against the input forward's path, which is one of my goals to implement in a Struts 1.3.x timeframe. Joe Joe, I hope you don't think I'm labouring a point after the big discussion last week, but regarding a view controller registered against the input forward's path, I just don't get the paradigm. It seems like an unnecessary complexity when you can do what Matt suggested and point the input attribute at a 'loader' action mapping. As Struts is designed now, setting the "input" attribute of an action mapping to point to another action mapping results in two passes through the request processor for a single HTTP request. This is not a use case for which Struts is designed or tested, and which could have strange side effects. Certainly, many people use it today without problems, but why not move Struts towards a clearly defined usage pattern which doesn't involve any grey areas like this? Having a loader action decouples it from the validation+processing action, which seems friendly and OO to me. Then you can use that loader action from anywhere - can you say the same about your view controller registered against the input forward path? When I say that it's registered against the input forward path, I don't mean that it's connected to the validating action mapping. I mean that the system is configured so that any time it is headed to the path defined as the input forward path, it will execute one or more view controllers. Therefore, it doesn't matter whether you are presenting the form for the first time or on a subsequent pass; the view controller code would still be executed. To me this seems "more OO" because it associates the processing code with the context in which it is used. No one needs to remember a sequence of actions which must be chained; they just trust that the request context (including the session and application) have the right data in the right places, and then small adjustments necessary to rendering the view can be encapsulated cleanly. Does that help at all? Joe -- Joe Germuska [EMAIL PROTECTED] http://blog.germuska.com "Narrow minds are weapons made for mass destruction" -The Ex - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: DynaValidatorForm 'forgets' request-attribute on redisplay after validation
On 11/23/2004 02:20 PM Joe Germuska wrote: Your action isn't executed if validation fails. However, the validation is performed on a second request, so the object placed into the scope before the form was presented is no longer there. If your categories are really relatively static, consider managing them in Application scope rather than request. I often have one or more plugins which initialize common menus like states and provinces or months of the year and place them into the application scope (I like to use the DigestingPlugIn). Your code doesn't look like there's anything particularly request-sensitive about the category tree. Some people make lists a property of the form itself. This is also one of the core use cases for some kind of view controller registered against the input forward's path, which is one of my goals to implement in a Struts 1.3.x timeframe. Joe Joe, I hope you don't think I'm labouring a point after the big discussion last week, but regarding a view controller registered against the input forward's path, I just don't get the paradigm. It seems like an unnecessary complexity when you can do what Matt suggested and point the input attribute at a 'loader' action mapping. Having a loader action decouples it from the validation+processing action, which seems friendly and OO to me. Then you can use that loader action from anywhere - can you say the same about your view controller registered against the input forward path? You have to do the loading without validation anyway, i.e. you need that first action. So how do you hook up your view controller to the loading action, or do you have some further mechanism that allows you to have only one action, tweaking validation on or off somehow? Adam - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: DynaValidatorForm 'forgets' request-attribute on redisplay after validation
The problem is, that the given form actually edits the categories-tree and as it is presented to the user after editing it, it should be updated after the form is submitted. Alexander Joe Germuska wrote: Your action isn't executed if validation fails. However, the validation is performed on a second request, so the object placed into the scope before the form was presented is no longer there. If your categories are really relatively static, consider managing them in Application scope rather than request. I often have one or more plugins which initialize common menus like states and provinces or months of the year and place them into the application scope (I like to use the DigestingPlugIn). Your code doesn't look like there's anything particularly request-sensitive about the category tree. Some people make lists a property of the form itself. This is also one of the core use cases for some kind of view controller registered against the input forward's path, which is one of my goals to implement in a Struts 1.3.x timeframe. Joe - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: DynaValidatorForm 'forgets' request-attribute on redisplay after validation
Alexander Czernay wrote:
I have a simple DynaValidatorForm
that is called whtin an action
that inserts so data into the request inside its execute method
public ActionForward execute(
ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response) throws Exception {
// read CategoriesTree and put it into request scope
try {
CategoriesModel categories = new CategoriesModel();
request.setAttribute(Constants.CATEGORY_TREE,
categories.getCategories());
} catch (ApplicationException e) {
request.setAttribute(Constants.CATEGORY_TREE, null);
}
return mapping.findForward("success");
}
This works quite well during the form's initial display. But if I enter
wrong values so that the validation fails, the CATEGORY_TREE-attribute
is missing and thus the JSP-view fails.
Isn't the execute-method called again when the validation fails?
Anything else wrong here?
Thanks for any help,
Alexander
Alexander - what happens on failure is based on the "input" attribute of
the action mapping. Right now you have it set to msys.categories-edit,
which I would guess is a tile definition. If you go directly to the tile
definition then no, the execute() method is not called, because you
bypassed the action.
You would have to set the input attribute to be /categories-edit.do to
get the execute() method to run again.
This may not work either because that action always validates the form
data. You most likely need to setup a "loader" action that just does the
CATEGORY-TREE loading, and forward back to that when there is an error.
If you wanted you could also setup your own ActionForm (don't use
DynaForms) and have the validate() method of the ActionForm check
whether it should actually validate or not. If you choose this option
search on the archives a bit, I'm pretty sure there is info about doing
something like that.
Matt
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Re: DynaValidatorForm 'forgets' request-attribute on redisplay after validation
Your action isn't executed if validation fails. However, the
validation is performed on a second request, so the object placed
into the scope before the form was presented is no longer there.
If your categories are really relatively static, consider managing
them in Application scope rather than request. I often have one or
more plugins which initialize common menus like states and provinces
or months of the year and place them into the application scope (I
like to use the DigestingPlugIn). Your code doesn't look like
there's anything particularly request-sensitive about the category
tree.
Some people make lists a property of the form itself. This is also
one of the core use cases for some kind of view controller registered
against the input forward's path, which is one of my goals to
implement in a Struts 1.3.x timeframe.
Joe
At 3:09 PM +0100 11/23/04, Alexander Czernay wrote:
I have a simple DynaValidatorForm
that is called whtin an action
that inserts so data into the request inside its execute method
public ActionForward execute(
ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response) throws Exception {
// read CategoriesTree and put it into request scope
try {
CategoriesModel categories = new CategoriesModel();
request.setAttribute(Constants.CATEGORY_TREE,
categories.getCategories());
} catch (ApplicationException e) {
request.setAttribute(Constants.CATEGORY_TREE, null);
}
return mapping.findForward("success");
}
This works quite well during the form's initial display. But if I
enter wrong values so that the validation fails, the
CATEGORY_TREE-attribute is missing and thus the JSP-view fails.
Isn't the execute-method called again when the validation fails?
Anything else wrong here?
Thanks for any help,
Alexander
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
--
Joe Germuska
[EMAIL PROTECTED]
http://blog.germuska.com
"Narrow minds are weapons made for mass destruction" -The Ex
DynaValidatorForm 'forgets' request-attribute on redisplay after validation
I have a simple DynaValidatorForm
that is called whtin an action
that inserts so data into the request inside its execute method
public ActionForward execute(
ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response) throws Exception {
// read CategoriesTree and put it into request scope
try {
CategoriesModel categories = new CategoriesModel();
request.setAttribute(Constants.CATEGORY_TREE,
categories.getCategories());
} catch (ApplicationException e) {
request.setAttribute(Constants.CATEGORY_TREE, null);
}
return mapping.findForward("success");
}
This works quite well during the form's initial display. But if I enter
wrong values so that the validation fails, the CATEGORY_TREE-attribute
is missing and thus the JSP-view fails.
Isn't the execute-method called again when the validation fails?
Anything else wrong here?
Thanks for any help,
Alexander
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
