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Struts & Hibernate
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| | | best choice for this use case ... ? | best choice for this use case ... ? 2007-12-03 - By Giovanni Azua
Back
hi,
I have the following use-case -I think should be pretty common- and
would like to
know what would be the best design choice:
- There is a form that contains an autocompleter field filled with all
stock indexes.
- In the same form there are other dependent input values displayed e.g.
exchange
rate that correspond to the selected index.
- Initially the input action makes sure the dependent fields are
correctly populated
i.e. they match the initially selected index.
Now when the user changes the index selection, some of the form fields
must also be updated to be consistent with the new selection.
These are the two design choices I have found using ajax so far:
1-. Have the master field index publish a topic and have the dependent
fields listen
to that topic and trigger the execution of an action. The problem I
encountered
here is that:
a) The request parameters e.g. historicBook0 are empty, don't
know how to
push them to the action, I could use javascript directly to
encode it but not sure
if this could lead to race conditions i.e. how will the
javascript ensure to execute
before the topic publication triggers execution of the action.
b) The widget autocompleter seem not to understand the result
of the action. I tried
using the json plugin and having a getter of the action
match the widget name but
does not work ...
Below find the not working sources with the problems described above.
2-. The second choice is using JSON RPC with javascript directly but
this approach
though viable seems rather frameworkless i.e. hacky to me.
My gut feeling is that solution #1 is the one but just don't know how to
solve those
issues.
TIA,
regards,
Giovanni
************** struts.xml *********************
<package name="remote" extends="json-default">
<action name="Remote*"
class="com.sag.optimizer.ui.web.action.remote.Remote{1}Action">
<result type="json"/>
</action>
</package>
************* mypage.jsp *********************
<%@ page contentType="text/html; charset=UTF-8 (See http://UTF-8.ora-code.com)"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<%@ taglib prefix="sx" uri="/struts-dojo-tags" %>
<s:url var="exchangeRates" action="RemoteExchangeRates.action" />
<s:form id="formAngleAlgoConfSimulation" action="%{targetAction}"
method="post" theme="%{currentTheme}">
<sx:autocompleter tooltip="Provide the first Historic Book"
valueNotifyTopics="/changedHistoricBook0" searchType="substring"
label="Historic Book 1" cssStyle="width: 250px;" dropdownHeight="180"
name="historicBook0" list="historicBooks" listKey="id" listValue="name"
/>
...
<sx:autocompleter tooltip="Provide the Currency Rate 1"
href="%{#exchangeRates}" autoComplete="false" preload="false"
listenTopics="/changedHistoricBook0" label="Currency Rate 1"
showDownArrow="false" cssStyle="width: 250px;" name="eurosPerListedUnit0" />
...
<s:submit value="%{buttonLabel}" align="center"/>
</s:form>
*********** Action ***************************
/**
* Determines the exchange rates for a Historic book pair
*/
public
class RemoteExchangeRatesAction
extends ActionSupport
{
//-- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
// public
//-- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
/**
* @(protected) the eurosPerListedUnit0
*/
public final double
getEurosPerListedUnit0()
{
return calculateFxRate(theHistoricBook0Key);
}
//-- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
/**
* @(protected) the eurosPerListedUnit1
*/
public final double
getEurosPerListedUnit1()
{
return calculateFxRate(theHistoricBook1Key);
}
//-- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
/**
* @(protected) aHistoricBook0Key the historicBook0Key to set
*/
public final void
setHistoricBook0Key(String aHistoricBook0Key)
{
theHistoricBook0Key = aHistoricBook0Key;
}
//-- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
/**
* @(protected) aHistoricBook1Key the historicBook1Key to set
*/
public final void
setHistoricBook1Key(String aHistoricBook1Key)
{
theHistoricBook1Key = aHistoricBook1Key;
}
//-- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
// members
//-- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
private String theHistoricBook0Key;
private String theHistoricBook1Key;
}
-- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ------
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