Java(TM) Boutique - Advanced Forms Handling in Struts 1.1

Tutorials : Advanced Forms Handling in Struts 1.1 :

The Selection List - Single Type

Since the single type selection list returns one value only, we can use the same setup in struts-config as for the radio buttons:

<form-bean name="singleSelectForm"
  type="org.apache.struts.action.DynaActionForm">
  <form-property name="control" type="java.lang.String"/>
</form-bean>

Now assume that we have a bean, Customer, with String properties firstName, lastName, address, and id. If you have a Collection of Customer beans then you can show a list of all the customers using jsp-code like this:

<html:select property="control" size="2">
  <logic:iterate id="customer" name="customers" type="hansen.playground.Customer">
    <html:option value="<%=customer.getId()%>">
      <bean:write name="customer" property="firstName"/> 
      <bean:write name="customer" property="lastName"/> 
    </html:option>
  </logic:iterate>
</html:select>

You'll have to specify the type attribute of the iterate tag or the scriptlet will fail.

There is a much nicer solution, however:

<html:select property="control" size="2">
  <html:options collection="customers" property="id" labelProperty="fullName"/> 
</html:select>

This time we use the options tag, where the collection attribute gives the name of the Collection of beans, and property gives the name of the property in the bean whose value will be returned when the form is submitted. labelProperty is the bean property that will be displayed. I've created a pseudo-property, fullName, in the Customer bean with a getter-method that returns the firstName and the lastName. In the browser we could have this presented:

The generated HTML looks like this:

<select name="control" size="2">
<option value="001">John Doe</option>
<option value="002" selected="selected">Peter Smith</option>
</select>

An almost identical solution, but using less confusing attribute names, is this:

<html:select property="control" size="2">
<html:optionsCollection name="customers" value="id" label="fullName"/> 
</html:select>

The current value of the list is again set or get in the execute method--as described previously.

The Selection List - multiple type

You may copy the solutions from the single choice selection list if you add multiple="true" to the html:select-tag:

<html:select multiple="true" property="control" size="2">
<html:optionsCollection name="customers" value="id" label="fullName"/> 
</html:select>

This time, however, you'll have to define the control property in the ActionForm as a String array:

<form-bean name="multiSelectForm"
  type="org.apache.struts.action.DynaActionForm">
  <form-property name="control" type="java.lang.String[]"/>
</form-bean>

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