Wang Hao: /* Testing total Price */

2016-08-31T03:15:27Z

Testing total Price

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{{Cat|Drools|030}}

<slideshow style="nobleprog" headingmark="⌘" incmark="…" scaled="true" font="Trebuchet MS" lang="中文版" headingmark2="。" >
;title: Drools Guvnor - Decision Table
;author: Bernard Szlachta (NobleProg Ltd)
</slideshow>

== Drools Guvnor - Decision Table ==
{{Can I use your material}}

== Presentation and Exercises ⌘。 ==
# Instructor does it himself and explains the steps
# The group does the exercise with the instructor
== ShoopingCart Fact Type (from previous exercises) ⌘。 ==
<source>
package nppack;
public class ShoppingCart implements java.io.Serializable
{
static final long serialVersionUID = 1L;
@org.kie.api.definition.type.Label("Total Price")
private java.math.BigDecimal totalPrice;

@org.kie.api.definition.type.Label("DiscountRate")
private java.math.BigDecimal discountRate;

@org.kie.api.definition.type.Label(value = "Total Price After Discount")
private java.math.BigDecimal totalPriceAfterDiscount;

public ShoppingCart()
{
}

public java.math.BigDecimal getTotalPrice()
{
return this.totalPrice;
}

public void setTotalPrice(java.math.BigDecimal totalPrice)
{
this.totalPrice = totalPrice;
}

public java.math.BigDecimal getDiscountRate()
{
return this.discountRate;
}

public void setDiscountRate(java.math.BigDecimal discountRate)
{
this.discountRate = discountRate;
}

public java.math.BigDecimal getTotalPriceAfterDiscount()
{
return this.totalPriceAfterDiscount;
}

public void setTotalPriceAfterDiscount(
java.math.BigDecimal totalPriceAfterDiscount)
{
this.totalPriceAfterDiscount = totalPriceAfterDiscount;
}

public ShoppingCart(java.math.BigDecimal totalPrice,
java.math.BigDecimal discountRate,
java.math.BigDecimal totalPriceAfterDiscount)
{
this.totalPrice = totalPrice;
this.discountRate = discountRate;
this.totalPriceAfterDiscount = totalPriceAfterDiscount;
}
}
</source>

== Modification to previous scenario ⌘。==
# Copy previous project to '''npproj2'''
# Make sure that the Group ID is '''nppack'''

== Applying Progressive Discounts 应用累进折扣 - 决策表。⌘==
We want to apply discounts according to the table below 根据下表应用折扣:
0 - 10,000 -> 0%
10,000(inc) - 50,000 -> 10%
50,000(inc) - 80,000 -> 12%
80,000(inc) - above -> 15%

* New Item -> Guided Decision Table
** Name: '''Progressive Discount Table'''
:[[File:ClipCapIt-160823-114756.PNG|400px]]

=== Applying Progressive Discounts - Source 应用分段折扣 - 源码。⌘===
* View Source
<source>
package nppack;

//from row number: 1
rule "Row 1 Progressive Discount Table"
dialect "mvel"
when
$sc : ShoppingCart( totalPrice >= 10000B , totalPrice < 50000B )
then
modify( $sc ) {
setDiscountRate( 0.1B )
}
end

//from row number: 2
rule "Row 2 Progressive Discount Table"
dialect "mvel"
when
$sc : ShoppingCart( totalPrice >= 50000B , totalPrice < 80000B )
then
modify( $sc ) {
setDiscountRate( 0.12B )
}
end

//from row number: 3
rule "Row 3 Progressive Discount Table"
dialect "mvel"
when
$sc : ShoppingCart( totalPrice >= 80000B )
then
modify( $sc ) {
setDiscountRate( 0.15B )
}
end
</source>

== Creating Test 。⌘==
:[[File:ClipCapIt-160823-123006.PNG|400px]]

== Problem with recurrence 。⌘==
:[[File:ClipCapIt-160831-111552.PNG|400px]]

== Stop condition for rules 。⌘==
<source>
package nppack;
dialect "mvel"
rule "Row 1 Progressive Discount Table"
when
$sc : ShoppingCart( totalPrice >= 10000B , totalPrice < 50000B , discountRate == null )
then
modify( $sc ) { setDiscountRate( 0.1B ) }
end

rule "Row 2 Progressive Discount Table"
when
$sc : ShoppingCart( totalPrice >= 50000B , totalPrice < 80000B , discountRate == null )
then
modify( $sc ) { setDiscountRate( 0.12B ) }
end

rule "Row 3 Progressive Discount Table"
when
$sc : ShoppingCart( totalPrice >= 80000B , discountRate == null )
then
modify( $sc ) { setDiscountRate( 0.15B ) }
end
</source>
== Calculating Total Price rule ==
<source>
package nppack;

import java.lang.Number;

rule "Calculate total price"
dialect "mvel"
when
$sc : ShoppingCart(discountRate != null, priceAfterDiscount == null)
then
modify( $sc ) {
setPriceAfterDiscount( $sc.totalPrice*(1-$sc.discountRate) ),
}
end
</source>

== Testing total Price ==
:[[File:ClipCapIt-160831-111709.PNG|400px]]

== Exercises 3.1 ⌘==
# Implement the decision table above 实现上面的决策表

== Exercises 3.2 ⌘==
# Create another rule which would calculate totalPrice after discount has been applied 建立一个规则，用以计算打折以后的 totalPrice

== Exercise 3.3 (optional)* ⌘==
# Add a field "Loyal Customer" in the shopping cart fact type and implement decision table, when if the customer is loyal customer, they have extra 1% off
# 在购物车的fact type里增加一个field "Loyal Customer" ，并且实现决策表, 当客户是loyal customer的时候, 他们再得到 1% 折扣

== Next Module ==
[[Drools Kie - Rule Templates]]

Drools Kie - Decision Table - Revision history

Wang Hao: /* Testing total Price */