property editor question.

[jefo]

Hi,

I'm having some dificulties to find a good example about a custom property edition that fits my needs.

I have a bean Channel that has a property of its same type.

public class Channel {

	private Long id;
	private String name;
	private String path;
   private Channel superChannel;

}

I have choosen a simpleformcontroller to handle the insertion form, I passed a collection of Channels to the view, and my jsp to list all the Channels is:

		<spring&#58;bind path="channel.superChannel">
		<td><fmt&#58;message key="cms.channel.form.superchannel.text"/></td>
		<td>
			<select name="<core&#58;out value="$&#123;status.expression&#125;"/>" size="5" style="width&#58; 300px;">
            	<core&#58;forEach var="channel" items="$&#123;channels&#125;">
                    <option value="<core&#58;out value="$&#123;channel.id&#125;"/>"<core&#58;if test="$&#123;status.value == channel.id&#125;"> selected</core&#58;if>><core&#58;out value="$&#123;channel.path&#125;"/></option>
            	</core&#58;forEach>
        	</select>
        	<br />
        	<font color="red"><core&#58;out value="$&#123;status.errorMessage&#125;"/></font>
		</td>
		</spring&#58;bind>

After fill the properties, choose an Channel and submit, I have this error message:

Failed to convert property value of type [java.lang.String] to required type [br.com.atom.cms.business.Channel] for property superChannel

I have read a lot of posts and know that I have to create a custom property editor to convert from a string to Channel, but i don't see any example that help me in it.

I know that i have to overide initBinder in my controller and register a custon editor, something like that:

protected void initBinder(HttpServletRequest request,
        ServletRequestDataBinder binder) {

        SimpleDateFormat dateFormat = new SimpleDateFormat("MMM-yy");
        dateFormat.setLenient(false);
        binder.registerCustomEditor(Date.class, null,
            new CustomDateEditor(dateFormat, true));
    }

But in this case, and all that i have seen, there is a built in property editor involved.

Shoud I use one of then, like ClassEditor?!?

Could someone give me a simple example of a custon property editor that converts a string to another object, like my Channel bean?!?

Tks.

[katentim]

Could someone give me a simple example of a custon property editor that converts a string to another object

Take a look at the source in the Spring src (in the distro.) in package org.springframework.beans.propertyeditors.

[jefo]

Tks for the advice katentim. I have made some tests but I'm still having problems:

I have created a custom property editor for Channel, here is it:

public class CustomChannelEditor extends PropertyEditorSupport {
	
	private ChannelDao channelDao;
	
	public CustomChannelEditor(ChannelDao channelDao) {
		this.channelDao = channelDao;
	}

	public void setAsString(String text) {
		System.err.println(": " + text);
		if (StringUtils.hasText(text)) {
			Channel channel = channelDao.load((Long) NumberUtils.parseNumber(text, Long.class));
			if(channel == null) {
				throw new IllegalArgumentException("Invalid Channel identification");
			} 
			setValue(channel);
		} else {
			setValue(null);
		}
	}
	
	public String getAsText() {
		Channel value = (Channel) getValue();
		return (value != null ? value.toString() : "");
	}
}

I have passed a DAO via constructor to this class to load the Channel indexed by the id filled in form, that I guess is in text parameter.

So in my controller I have overide the initBinder, here is it:

	protected void initBinder(HttpServletRequest request, ServletRequestDataBinder binder) throws ServletException {
		binder.registerCustomEditor(Channel.class, "channel.superChannel", new CustomChannelEditor(channelDao));
	}

and again, here is my jsp:

<spring&#58;bind path="channel.superChannel">
		<td><fmt&#58;message key="cms.channel.form.superchannel.text"/></td>
		<td>
			<select name="<core&#58;out value="$&#123;status.expression&#125;"/>" size="5" style="width&#58; 300px;">
            	<core&#58;forEach var="channel" items="$&#123;channels&#125;">
                    <option value="<core&#58;out value="$&#123;channel.id&#125;"/>"<core&#58;if test="$&#123;status.value == channel.id&#125;"> selected</core&#58;if>><core&#58;out value="$&#123;channel.path&#125;"/></option>
            	</core&#58;forEach>
        	</select>
        	<br />
        	<font color="red"><core&#58;out value="$&#123;status.errorMessage&#125;"/></font>
		</td>
		</spring&#58;bind>

The problem remains, I still getting this message error:

Failed to convert property value of type [java.lang.String] to required type [br.com.atom.cms.business.Channel] for property superChannel

Is there something that I have missed or that I have done wrong?

Regards.

[gmatthews]

It's setAsText, not setAsString

[jefo]

Tks gmatthews, you are right, I'm a dumb... :-)

Here is my final code, it can help peolpe with the same problem, tks guys.


My bean:

public class Channel {

   private Long id;
   private String name;
   private String path;
   private Channel superChannel;

  //getters and setters

}

The custom property editor:

public class CustomChannelEditor extends PropertyEditorSupport {
	
	private ChannelDao channelDao;
	
	public CustomChannelEditor(ChannelDao channelDao) {
		this.channelDao = channelDao;
	}

	public void setAsText(String text) {
		Channel channel = null;
		if (StringUtils.hasText(text)) {
			channel = channelDao.load((Long) NumberUtils.parseNumber(text, Long.class));
			if(channel == null) {
				throw new IllegalArgumentException("Invalid Channel identification");
			} 
			setValue(channel);
		} else {
			setValue(null);
		}
	}
	
	public String getAsText() {
		Channel value = (Channel) getValue();
		return (value != null ? value.toString() : "");
	}
}

My formcontroller:

	protected Map referenceData(HttpServletRequest request) throws Exception {
		Map<String, Object> refData = new HashMap<String, Object>&#40;&#41;;
		Collection channels = channelDao.list&#40;&#41;;
		refData.put&#40;"channels", channels&#41;;
		return refData;
	&#125;

	protected void initBinder&#40;HttpServletRequest request, ServletRequestDataBinder binder&#41; throws ServletException &#123;
		binder.registerCustomEditor&#40;Channel.class, new CustomChannelEditor&#40;channelDao&#41;&#41;;
	&#125;

Tks again.