Create a new class that extends the built in com.softslate.commerce.businessobjects.product.ProductBean class. To keep things clean, we strongly recommend you place all your custom classes in a separate Java package. We'll call our class CustomProduct and we'll put it in a new package named com.softslate.commerce.demo . Here's the source code for our new class:

									
package com.softslate.commerce.demo;

import com.softslate.commerce.businessobjects.product.ProductBean;

public class CustomProduct extends ProductBean {
	
	private static final long serialVersionUID = 6874908321131548936L;
	
	String author = null;

	public String getAuthor() {
		return author;
	}

	public void setAuthor(String author) {
		this.author = author;
	}

}
									

Note that we are extending the built-in com.softslate.commerce.businessobjects.product.ProductBean class. Strictly speaking, you don't have to extend the built-in class, but you must implement the com.softslate.commerce.businessobjects.product.Product interface.

Create the Hibernate mapping file for the new class. The Hibernate mapping file tells Hibernate how to map a class' properties to the columns of the database table it corresponds to. Make a copy of the ProductBean.hbm.xml file, place it next to the new CustomProduct.class file, rename it CustomProduct.hbm.xml, and replace the existing <subclass> tag with the following:

									
<subclass 
	name="com.softslate.commerce.demo.CustomProduct">
	<property name="author" length="255"/>
</subclass>
									

If you are adding more than one property to your extended class, include all of them inside the <subclass> tag.

To ensure that your new class is used when Hibernate loads it lazily, add the lazy="false" attribute to the opening <class> tag:

							
<class 
	name="com.softslate.commerce.businessobjects.product.Product"
	table="Product"
	lazy="false">
									

Now add the new column to the product database table:

									
ALTER TABLE sscProduct ADD author VARCHAR(255);
									

Update the product database table's class field to use the new custom class. This tells Hibernate to instantiate instances of the new class when loading data from the database:

									
UPDATE sscProduct SET class = 'com.softslate.commerce.demo.CustomProduct';
									

In the /WEB-INF/classes/appComponents.properties file, update the value of the productImplementer property with the fully-qualified classname of our new custom class:

									
productImplementer = com.softslate.commerce.demo.CustomProduct
									

This tells the application to load the CustomProduct.hbm.xml file as part of the Hibernate initialization process.

To display our new author field, first put some data into the new column of the database:

									
UPDATE sscProduct SET author = 'Truman Capote' WHERE productID = 1;
									

Then, create a custom version of the product.jsp JSP template in the /WEB-INF/layouts/custom/product directory. Paste some JSP code into the custom template that displays the value of the new field if it is defined:

									
<c:if test="${!empty product.author}">
	<tr>
		<td class="productLabel" valign="top" nowrap="nowrap">
			Author:
		</td>
		<td class="productData" valign="top">
			<bean:write name="product" property="author"/>
		</td>
	</tr>
</c:if>
									

Create a new class that extends the built in com.softslate.commerce.administrator.product.ProductForm class. This will handle the processing and display of the the control screen in the administrator. We'll call our class CustomProductForm and we'll put it in a package named com.softslate.commerce.demo . Here's the source code for our new CustomProductForm class:

									
package com.softslate.commerce.demo;

import java.util.Arrays;

import javax.servlet.http.HttpServletRequest;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.struts.action.ActionErrors;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionMessage;
import org.apache.struts.action.ActionMessages;

import com.softslate.commerce.administrator.product.ProductForm;

/**
 * Adding author field
 * 
 * @author David Tobey
 */
public class CustomProductForm extends ProductForm {

	private static final long serialVersionUID = 1571534730516598703L;

	static Log log = LogFactory.getLog(CustomProductForm.class);

	// Add the new field to the list of fields
	private String[] fields = { "productID", "code", "name", "keywords",
			"shortDescription", "description", "isActive", "unitCost",
			"unitPrice", "altPrice", "weight", "header", "footer", "isTaxed",
			"smallImage", "mediumImage", "largeImage", "extra1", "extra2",
			"extra3", "extra4", "extra5", "primaryCategoryID",
			"manufacturerID", "productOrder", "author" };

	// Add a human readable label for it
	private String[] fieldLables = { "Product ID", "Code", "Name", "Keywords",
			"Short Desc", "Description", "Active", "Cost", "Price",
			"Alt Price", "Weight", "Header", "Footer", "Taxed", "Small Image",
			"Medium Image", "Large Image", "Extra 1", "Extra 2", "Extra 3",
			"Extra 4", "Extra 5", "Pri Category", "Manufacturer", "Order",
			"Author" };

	// Should it be displayed on the control screen by default? Yes.
	private String[] displayFields = { "code", "name", "isActive", "unitPrice",
			"productOrder", "author" };

	private String[] searchableFields = { "code", "name", "keywords",
			"shortDescription", "extra1", "extra2", "extra3", "extra4",
			"extra5", "author" };

	// Need a property for the control screen's edit mode - a String[]
	private String[] author = null;

	public String[] getAuthor() {
		return author;
	}

	public void setAuthor(String[] author) {
		this.author = author;
	}

	public String[] getDisplayFields() {
		return displayFields;
	}

	public void setDisplayFields(String[] displayFields) {
		this.displayFields = displayFields;
	}

	public String[] getFieldLables() {
		return fieldLables;
	}

	public void setFieldLables(String[] fieldLables) {
		this.fieldLables = fieldLables;
	}

	public String[] getFields() {
		return fields;
	}

	public void setFields(String[] fields) {
		this.fields = fields;
	}

	public String[] getSearchableFields() {
		return searchableFields;
	}

	public void setSearchableFields(String[] searchableFields) {
		this.searchableFields = searchableFields;
	}

	// Let's say we must have an author - so let's add it to the validation
	public ActionErrors validate(ActionMapping mapping,
			HttpServletRequest request) {
		if (log.isDebugEnabled())
			log.debug("Starting validation.");
		setProperties();
		// Run the original validations
		ActionErrors errors = super.validate(mapping, request);
		if (getProductID() != null) {
			for (int i = 0; i < getProductID().length; i++) {
				if (Arrays.asList(getDisplayFields()).contains("code")) {
					if (getAuthor().length < i + 1 || getAuthor()[i] == null
							|| getAuthor()[i].equals("")) {
						errors.add(ActionMessages.GLOBAL_MESSAGE,
								new ActionMessage("errors.required", "Author"));
					}
				}
			}
		}
		return errors;
	}
}
									

Similarly, create a new class that extends the built in com.softslate.commerce.administrator.product.ProductAddEditForm class. This will handle the processing and display of the the product detail screen in the administrator. We'll call our class CustomProductAddEditForm . Here's the source code for this class:

package com.softslate.commerce.demo;

import javax.servlet.http.HttpServletRequest;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.struts.action.ActionErrors;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionMessage;
import org.apache.struts.action.ActionMessages;

import com.softslate.commerce.administrator.product.ProductAddEditForm;

/**
 * Adding author property
 * 
 * @author David Tobey
 * 
 */
public class CustomProductAddEditForm extends ProductAddEditForm {

	private static final long serialVersionUID = 4589930821507654940L;

	static Log log = LogFactory.getLog(CustomProductAddEditForm.class);

	private String author = null;

	public String getAuthor() {
		return author;
	}

	public void setAuthor(String author) {
		this.author = author;
	}

	public ActionErrors validate(ActionMapping mapping,
			HttpServletRequest request) {
		if (log.isDebugEnabled())
			log.debug("Starting validation.");
		initializeProperties(mapping, request);
		super.validate(mapping, request);
		if (getCode() == null || getCode().equals("")) {
			getErrors().add(ActionMessages.GLOBAL_MESSAGE,
					new ActionMessage("errors.required", "Author"));
		}
		return getErrors();
	}
}
									

Now let's tell Struts to use our new form classes instead of the defaults. Add the following Action Form definitions to the <form-beans> section of /WEB-INF/conf/administrator/core/struts-config-custom.xml:

		<!-- Adding an author field to the product admin screens  -->
		<form-bean
			name="productAddEditForm"
			type="com.softslate.commerce.demo.CustomProductAddEditForm">
		</form-bean>
		<form-bean
			name="productForm"
			type="com.softslate.commerce.demo.CustomProductForm">
		</form-bean>
									

Next is to add the HTML form elements for the new field to our JSP templates. Let's start with the product detail screen. The JSP template responsible for it is /WEB-INF/templates/administrator/default/product/productFormGuts.jsp. We want to create a custom version of that file, so create a new file of the same name in the custom directory: /WEB-INF/templates/administrator/custom/product/productFormGuts.jsp

In our custom version of productFormGuts.jsp, place the following content to display a text box for the new author field. Note we'll include the original JSP file to avoid duplication:

									
<%@ include file="/WEB-INF/layouts/default/core/tagDefinitions.jsp" %>

<!-- Start custom productFormGuts.jsp -->
<tr>
	<td class="genericLabel">Author:</td>
	<td>
		<html:text maxlength="100" name="productAddEditForm" property="author"/>
	</td>
</tr>
<tr>
	<td>
		 
	</td>
	<td class="genericData">
		Enter the author of this book.
		<br />
		<br />
	</td>
</tr>

<jsp:include page="/WEB-INF/templates/administrator/default/product/productFormGuts.jsp"/>

<!-- End custom productFormGuts.jsp -->
									

Next is the control screen for products. The JSP template responsible for displaying the product fields on that screen is /WEB-INF/templates/administrator/default/product/productFieldColumns.jsp. We want to use the same file, but just add some new logic for the author field. So let's place a copy of productFieldColumns.jsp in the custom directory: /WEB-INF/templates/administrator/custom/product/productFieldColumns.jsp

In our copy of productFieldColumns.jsp, add the following lines in the appropriate spots in that file to display the new author field, both when "edit mode" is on and when it is off. (Some analysis of the JSP tags is necessary here!)

When edit mode is on:

									
<logic:equal name="field" value="author">
	<input type="text" size="15" maxlength="100" 
		name="<bean:write name="field"/>" 
		value="<bean:write name="item" 
		property="<%= field %>"/>" 
		class="genericGridData"/>
</logic:equal>
									

When edit mode is off:

									
<logic:equal name="field" value="partNumber">
	<bean:write name="item" property="<%= field %>"/>
</logic:equal>