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Posted to user@struts.apache.org by Heather Buch <hb...@www.thebuchs.dk> on 2003/07/02 10:32:38 UTC
Re: struts-user Digest 1 Jul 2003 13:07:49 -0000 Issue 3513
Hi Adam,
Thanks for the reply.
In my step #2, I always save the dataset in a bean in the session or request.
I never save data in the form bean from an action. If the idea is to save
data in a form bean before showing the form to the user, than I'm probably
doing it all wrong.
Here is an example of what I might do to populate a select menu (and it is
pretty circuitious, which means it's probably wrong):
In a typical "list" action, I might do this to save a list of dates
in the session:
List mydates = Constants.getDates();
session.setAttribute("coursedates", mydates);
then, in my form bean, I would have these methods (which would
only be invoked *after* the form was displayed to the user:
public void setPlanlagtChange(String key, Object value ) {
_planlagtdatochanges.put(key, value);
}
public Object getPlanlagtChange(String key) {
return _planlagtdatochanges.get(key);
}
public Map getPlanlagtChanges() {
return _planlagtdatochanges;
}
Then in my jsp I have this for a select menu. It cycles over the "coursedates"
list that is in the session. My jsp pages never take anything from the form
bean. They only write to the form bean:
<html:select property="<%= "planlagtChange(" + String.valueOf(planlagtid) +
")" %>" value="ingen">
<html:option value="ingen">
<bean:message key="no.change"/>
</html:option>
<!-- cycle over dates for planlagt fag select box -->
<html:options name="coursedates"/>
<!-- end cycle over dates for planlagt fag select box -->
</html:select>
This works ok for a select menu, but I can't make radio buttons work. I am
willing to save stuff to the form bean before the user sees the form, but I do
not understand why they want me to do it that way.
Best,
Heather
----------------------------------
Adam Hardy wrote:
Date: Tue, 01 Jul 2003 13:20:36 +0200
From: Adam Hardy <ah...@cyberspaceroad.com>
To: Struts Users Mailing List <st...@jakarta.apache.org>
Subject: Re: where does a form element get and put it's data
Surely you have the same issue with selecting the correct option in the
select box as you do with the radio buttons?
If I understand correctly what you are saying, you are actually talking
about 2 seperate datasets: the dataset that you are going to edit in the
form, and the dataset that you use to populate radio buttons or select
boxes.
In the average application I write, the datasets for dropdowns etc
rarely gets edited, so I retrieve it from the database and keep it,
normally as a list of beans, in APPLICATION_SCOPE, and I keep the
editable data in the request or the session. But to get the editable
data into an HTML form, I always have to call it up first (your step 2)
and put it into the ActionForm. How else are you going to get it into
the textboxes, checkboxes, selectboxes etc?
If I want to keep my editable data around server-side for some reason, I
keep the form in the session, but normally I don't, so I keep my forms
in my request. Normally too I only ever edit one bean of data at a time.
I have done editable lists of many beans using the nested-beans plug-in too.
Hope I understood you correctly and haven't been waffling on beside the
point.
Adam
Heather Buch wrote:
> I know the Struts form bean raises a lot of discussion. Personally, form beans
> cause me a lot of confusion too, maybe not in the same way that they confuse
> others, but maybe so. I'll attempt to explain.
>
> I feel like it is not consistent whether a form bean is first used upon
> creating, or submitting a form.
>
> Basically, my Action classes fall into two general categories:
>
> 1. "list" action classes which get data from my database and put it into a
form.
> 2. "save" action classes which take data from the form and write to the db.
>
> As far as I am concerned, this is how use of a form bean makes sense to me:
>
> 1. user requests a form
> 2. "list" action executes and saves some database data into a the session or
> request.
> 3. user fills out and submits form
> 4. form bean collects data
> 5. "save" action executes and gets data out of form bean
>
> But sometimes I feel like struts intends for me to use a form bean like this:
>
> 1. user requests a form
> 2. "list" action executes and saves some database data into a the session or
> request.
> 3. "list" action creates a form bean and puts data into it (I don't like this.
> I don't want to see my form bean until after form is submitted)
> 4. user fills out and submits form
> 5. form bean collects data
> 6. "save" action executes and gets data out of form bean
>
> I cannot understand how some of the jsp tags work vis a vis form beans.
>
> For example, if, in a "list" action, I make a list of beans of database
> information and set that list in the session, I can then use the "html:select"
> tag to retrieve data from the bean I have set in the session, and write it to
> the form bean. This makes sense.
>
> However, if I want to use a prepopulated radio button, then, in my "list"
> action I have to get data from the database and put it in my *form bean*.
> Based on what I understand, the html:radio "property" attribute will only
> prepopulate the radio button if the information retrieved from the *form bean*
> via "property" matches the "value" attribute of html:radio. But I do not want
> to *retrieve* infromation from my form bean when I display my form. I want to
> retrieve information from the bean that my "list" action has saved in the
> session. I only want to retrieve information from my form bean during my
> "save" action.
>
> so it seems like the flow of information from database to form bean and then
> to action is kind of inconsistent. I hope this makes sense. If you need some
> examples, let me know and I'll try to create them.
>
> Best,
>
> Heather Buch
>
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Re: struts-user Digest 1 Jul 2003 13:07:49 -0000 Issue 3513
Posted by Adam Hardy <ah...@cyberspaceroad.com>.
OK, should I understand that all your forms are initially blank, without
any text in the boxes? That would explain why I was talking confusingly.
Anyway, you are doing fine NOT storing the select-box-data in the form.
What you are doing seems complicated, although I can't really say. It
doesn't sound like you are using struts in an optimal fashion. There are
a number of different, quick & easy ways of setting up your
struts-config, actions and jsps to get a page working. Which one would
be best for you, I can't say without knowing what your model looks like.
You may already have the best way.
You can do the select-boxes more easily than you are at the moment. For
a start I would put the 'ingen' bean into the top of the list of beans
during your action, so you don't have to worry about it in your JSP.
Have a look at html-select.jsp in the struts-exercise-taglib.war that
comes with struts.
As for getting a group of radio buttons to work, I was looking for an
example in my work and I realised I've never used them. You'd have to
look on the struts website in the user guide. You would probably iterate
over a list with a logic:iterate tag to get the values, but I'm not sure
what you would do to get the property.
Heather Buch wrote:
> Hi Adam,
>
> Thanks for the reply.
>
> In my step #2, I always save the dataset in a bean in the session or request.
> I never save data in the form bean from an action. If the idea is to save
> data in a form bean before showing the form to the user, than I'm probably
> doing it all wrong.
>
> Here is an example of what I might do to populate a select menu (and it is
> pretty circuitious, which means it's probably wrong):
>
> In a typical "list" action, I might do this to save a list of dates
> in the session:
>
> List mydates = Constants.getDates();
> session.setAttribute("coursedates", mydates);
>
> then, in my form bean, I would have these methods (which would
> only be invoked *after* the form was displayed to the user:
>
> public void setPlanlagtChange(String key, Object value ) {
> _planlagtdatochanges.put(key, value);
> }
>
> public Object getPlanlagtChange(String key) {
> return _planlagtdatochanges.get(key);
> }
>
> public Map getPlanlagtChanges() {
> return _planlagtdatochanges;
> }
>
> Then in my jsp I have this for a select menu. It cycles over the "coursedates"
> list that is in the session. My jsp pages never take anything from the form
> bean. They only write to the form bean:
>
> <html:select property="<%= "planlagtChange(" + String.valueOf(planlagtid) +
> ")" %>" value="ingen">
>
> <html:option value="ingen">
> <bean:message key="no.change"/>
> </html:option>
> <!-- cycle over dates for planlagt fag select box -->
> <html:options name="coursedates"/>
> <!-- end cycle over dates for planlagt fag select box -->
> </html:select>
>
> This works ok for a select menu, but I can't make radio buttons work. I am
> willing to save stuff to the form bean before the user sees the form, but I do
> not understand why they want me to do it that way.
>
> Best,
>
> Heather
>
> ----------------------------------
> Adam Hardy wrote:
>
> Date: Tue, 01 Jul 2003 13:20:36 +0200
> From: Adam Hardy <ah...@cyberspaceroad.com>
> To: Struts Users Mailing List <st...@jakarta.apache.org>
> Subject: Re: where does a form element get and put it's data
> Surely you have the same issue with selecting the correct option in the
> select box as you do with the radio buttons?
>
> If I understand correctly what you are saying, you are actually talking
> about 2 seperate datasets: the dataset that you are going to edit in the
> form, and the dataset that you use to populate radio buttons or select
> boxes.
>
> In the average application I write, the datasets for dropdowns etc
> rarely gets edited, so I retrieve it from the database and keep it,
> normally as a list of beans, in APPLICATION_SCOPE, and I keep the
> editable data in the request or the session. But to get the editable
> data into an HTML form, I always have to call it up first (your step 2)
> and put it into the ActionForm. How else are you going to get it into
> the textboxes, checkboxes, selectboxes etc?
>
> If I want to keep my editable data around server-side for some reason, I
> keep the form in the session, but normally I don't, so I keep my forms
> in my request. Normally too I only ever edit one bean of data at a time.
> I have done editable lists of many beans using the nested-beans plug-in too.
>
> Hope I understood you correctly and haven't been waffling on beside the
> point.
>
> Adam
>
> Heather Buch wrote:
>
>>I know the Struts form bean raises a lot of discussion. Personally, form beans
>>cause me a lot of confusion too, maybe not in the same way that they confuse
>>others, but maybe so. I'll attempt to explain.
>>
>>I feel like it is not consistent whether a form bean is first used upon
>>creating, or submitting a form.
>>
>>Basically, my Action classes fall into two general categories:
>>
>>1. "list" action classes which get data from my database and put it into a
>
> form.
>
>>2. "save" action classes which take data from the form and write to the db.
>>
>>As far as I am concerned, this is how use of a form bean makes sense to me:
>>
>>1. user requests a form
>>2. "list" action executes and saves some database data into a the session or
>>request.
>>3. user fills out and submits form
>>4. form bean collects data
>>5. "save" action executes and gets data out of form bean
>>
>>But sometimes I feel like struts intends for me to use a form bean like this:
>>
>>1. user requests a form
>>2. "list" action executes and saves some database data into a the session or
>>request.
>>3. "list" action creates a form bean and puts data into it (I don't like this.
>>I don't want to see my form bean until after form is submitted)
>>4. user fills out and submits form
>>5. form bean collects data
>>6. "save" action executes and gets data out of form bean
>>
>>I cannot understand how some of the jsp tags work vis a vis form beans.
>>
>>For example, if, in a "list" action, I make a list of beans of database
>>information and set that list in the session, I can then use the "html:select"
>>tag to retrieve data from the bean I have set in the session, and write it to
>>the form bean. This makes sense.
>>
>>However, if I want to use a prepopulated radio button, then, in my "list"
>>action I have to get data from the database and put it in my *form bean*.
>>Based on what I understand, the html:radio "property" attribute will only
>>prepopulate the radio button if the information retrieved from the *form bean*
>>via "property" matches the "value" attribute of html:radio. But I do not want
>>to *retrieve* infromation from my form bean when I display my form. I want to
>>retrieve information from the bean that my "list" action has saved in the
>>session. I only want to retrieve information from my form bean during my
>> "save" action.
>>
>>so it seems like the flow of information from database to form bean and then
>>to action is kind of inconsistent. I hope this makes sense. If you need some
>>examples, let me know and I'll try to create them.
>>
>>Best,
>>
>>Heather Buch
>>
>
>
>
>
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>
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