CPI-Router Use Case-Conditional routing based on XPath which can occur multiple times

This blog covers some ideas and approaches on routing of messages based on a particular XPath condition in SAP CPI.

Requirement :

Flow : SAP S4 HANA –> CPI –> 3rd party SFTP
Source : IDOC, Target : External Definition
IDOCs having no /ZCUSTOM_ZINVOIC02_INV/IDOC/E1EDP01/ZCUSTOM_E1EDP01_SUBITEM/ZFLAG=”A” need to be terminated in CPI and not sent to target system.
IDOCs having mixed values i.e combination of “A” and other values can be sent but mapping needs to be considered only for ZFLAG=”A”
Source is IDOC and target is a custom XML External definition
Multiple IDOCs can be sent in a batch

3 approaches were explored as below :

Approach 1 :

Use a message mapping and apply logic for checking ZFLAG value at root IDOC level. Suppress IDOCs having no Lines in IDOC having ZFLAG=A.
Use a router in next step and check if count of IDOCs is zero.
- If count is not zero, pass it to main mapping in default route where IDOC-External Definition mapping is done (Default Route)
- If count is zero then end that batch here ( Router Condition : count(//IDOC) = 0 )

Approach 2 :

Use a Groovy Script which keeps a count of all items having ZFLAG=”A” and sets the count as a Exchange Property
Use a router at next step to check if Exchange Property count is greater than zero
- If count is not zero, pass it to default route where IDOC-External Definition mapping is done and sent ahead
- If count is zero, then end that IDOC in CPI

Approach 3 :

Use a content modifier to capture all actual values of Flag in an Exchange Property and use another Exchange Property to capture the applicable value (Here it is “A”)
Use a router in next step and check if Applicable Value Exchange Property value exists in Actual value exchange property.
- If applicable value exists in actual value list, pass it to main mapping in default route where IDOC-External Definition mapping is done
- If applicable value does not exist in actual value list, end that IDOC in CPI

All 3 approaches are covered in detail below :

Approach 1 : Filter Mapping + Router + Main Mapping Combination

Approach%201%20%3A%20Filter%20Mapping%20+%20Router%20+%20Main%20Mapping

Figure 1- Approach 1 : Filter Mapping + Router + Main Mapping

Step 1 : Message Mapping which suppresses the IDOCs which do not have even one line item with ZFLAG=A

Use a message mapping and apply filter of checking ZFLAG value at root IDOC level and at E1EDP01 segment (Rest segments can be mapped one-one)
Suppress IDOCs having no Line item in IDOC having ZFLAG=A in mapping.

Mapping%20Logic%20for%20filtering%20IDOCs%20that%20do%20not%20have%20any%20line%20items%20with%20ZFLAG%3DA

Figure 2 – Mapping Logic for filtering IDOCs that do not have any line items with ZFLAG=A (Logic applicable for Root IDOC segment and E1EDP01 segment)

NOTE : After ifWithoutElse, a UDF is used which returns a single true, if atleast a single line item with ZFLAG=A exists in an IDOC, else, it will return false which will suppress that IDOC itself (UDF is not discussed here)

Step 2 : Conditional Routing

Step 2.1 : If count is not zero pass it to main mapping in default route where IDOC-External Definition mapping is done (Default Route)
Step 2.2 : If count is zero then end that batch here ( Router Condition : count(//IDOC) = 0 )

Router%20Condition%20for%20terminating%20IDOCs

Figure 3 – Router Condition for terminating IDOCs

Step 3 : Split and Map IDOC to XML as applicable

Simulation Results for Positive test Case : When IDOCs in a batch contains atleast one line item with ZFLAG=A. 4 IDOCs triggered in a batch, 2 have no line items with ZFLAG=A and 2 IDOCs have mixed values

Simulation%20result%20of%20Mapping%20Logic

Figure 4 – Simulation result of Mapping Logic for positive test case i.e when batch of IDOCs have atleast one line having ZFLAG=A. Out of 4 IDOCs in a batch, 2 are having mixed values of ZFLAG and 2 are having no line items with ZFLAG=A which are suppressed as shown above.

Simulation%20Result%20of%20iflow%20for%20positive%20test%20case%20i.e%20when%20batch%20of%20IDOCs%20have%20atleast%20one%20line%20having%20ZFLAG%3DA

Figure 5 – Simulation Result of iflow for positive test case i.e when batch of IDOCs have atleast one line having ZFLAG=A. Out of 4 IDOCs in a batch, 2 are having mixed values of ZFLAG and 2 are having no line items with ZFLAG=A which are suppressed in Mapping and the relevant filtered IDOCs are sent ahead.

Simulation Results for Negative test Case : When none of the IDOCs in a batch have line items with ZFLAG=A

Simulation%20result%20of%20mapping%20logic%20for%20negative%20test%20case

Figure 6 – Simulation result of mapping logic for negative test case i.e when batch of IDOCs have no lines having ZFLAG=A. Out of 2 IDOCs in a batch, none of them are having line items with ZFLAG=A which are suppressed as shown above.

Simulation%20Result%20when%20batch%20of%20IDOCs%20have%20no%20lines%20having%20ZFLAG%3DA

Figure 7 – Simulation Result of iflow for negative test case i.e when batch of IDOCs have no lines having ZFLAG=A. Out of 2 IDOCs in a batch, none of them are having line items with ZFLAG=A which are suppressed in Mapping out and hence count of IDOC is zero here, hence this batch is terminated in CPI.

Approach 2 : Groovy + Router + Main Mapping Combination

Approach%202%20%3A%20Groovy%20+%20Router%20+%20Main%20Mapping%20Combination

Figure 8 – Approach 2 : Groovy + Router + Main Mapping

Step 1 : Split the IDOCs

Step 2 : Groovy Script which keeps a count of all items having ZFLAG=”A” and sets the count as a Exchange Property-ZFLAG_Count

// Purpose of using this groovy - per requirement, if an IDOC has no Line item (E1EDP01) containing ZCUSTOM_E1EDP01_ITEM/ZFLAG=A, then no output XML for that IDOC should be created from CPI.
// Below script will return the count of ZFLAG=A in Exchange property, If count > 1 then send idoc to mapping, else end such message in CPI

import com.sap.gateway.ip.core.customdev.util.Message;
import java.util.HashMap;
import groovy.util.XmlSlurper ;
import groovy.xml.XmlUtil;
import org.w3c.dom.*;
import javax.xml.parsers.*;
import java.io.*;
import java.io.StringReader;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.xml.sax.InputSource;
def Message processData(Message message) 
{
def mapProperties = message.getProperties();

//read message as string
def body = message.getBody(java.lang.String) as String;

//initialize variables
def count=0;

//Create a DocumentBuilder
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();
Document doc = builder.parse(new InputSource(new StringReader(body)));
doc.getDocumentElement().normalize();

//Extract the root element
Element root = doc.getDocumentElement();
System.out.println("Root element " + doc.getDocumentElement().getNodeName());
NodeList nList = doc.getElementsByTagName("E1EDP01");

for (int temp = 0; temp < nList.getLength(); temp++) 
{
    Node nNode = nList.item(temp);
    Element eElement = (Element) nNode;
              
    if (eElement.getElementsByTagName("ZFLAG").item(0).textContent.equals("A"))
    count++;
}
    message.setProperty("ZFLAG_Count", count);
    return message;
    
}

Step 3 : Use a router at next step to check if Exchange Property ZFLAG_Count
- Step 3.1 : if count is greater than zero, pass it to default route where IDOC-External Definition mapping is done and sent ahead (Default Route)
- Step 3.2 : If No, then end that IDOC in CPI (Condition : ${property.ZFLAG_Count} = ‘0’)
  Figure 9 – Router Configuration
Step 4 : Mapping IDOC-XML as applicable

Simulation Results for Positive test Case : When IDOC in a batch contains atleast one line item with ZFLAG=A. 4 IDOCs triggered in a batch, 2 have no line items with ZFLAG=A and 2 IDOCs have mixed values

Figure%20-%20IDOCs%20having%20no%20ZFLAG%3DA%20ended%20in%20CPI

Figure 10 – IDOCs having atleast one ZFLAG=A sent to default route.

Figure%20-%20IDOCs%20having%20atleast%20one%20ZFLAG%3DA%20sent%20to%20default%20route

Figure 11 – IDOCs having no ZFLAG=A ended in CPI

Simulation Results for Negative test Case : When none of the IDOCs in a batch have line items with ZFLAG=A

Figure%20-%20No%20IDOCs%20in%20a%20batch%20contain%20line%20items%20with%20ZFLAG%3DA%20ended%20in%20CPI

Figure 12 – No IDOCs in a batch contain line items with ZFLAG=A ended in CPI

Approach 3 : Content Modifier + Router + Main Mapping Combination

Figure%2010%20-%20Approach%203%20%3A%20Content%20Modifier%20+%20Router%20+%20Main%20Mapping%20Combination

Figure 13 – Approach 3 : Content Modifier + Router + Main Mapping

Step 1 : Split the IDOCs
Step 2 : Use a content modifier
- capture all actual values of ZFLAG in an Exchange Property (ZFLAG_ACTUAL_VALUES-string-join((//E1EDP01/ZCUSTOM_E1EDP01_SUBITEM/ZFLAG/text()),’,’)
- capture all applicable values of ZFLAG in an Exchange Property (ZFLAG_APPLICABLE_VALUES). Here this value is hardcoded to “A” as per requirement. (This can also be externalized)

NOTE : Here another exchange property – ZFLAG_COUNT is used with XPath value : count(//E1EDP01[ZCUSTOM_E1EDP01_SUBITEM/ZFLAG=”A”])(We can leverage this as an alternative to Groovy script in Approach 2 as well!)

Content%20Modifier%20Exchange%20Properties%20%28ZFLAG_COUNT%20value%20can%20be%20levraged%20instead%20of%20Approach%202%20Groovy%20script%20as%20well%21%29
Figure 14 – Content Modifier Exchange Properties (ZFLAG_COUNT value can be levraged instead of Approach 2 Groovy script as well!)

Step 3 : Use a router in next step and check if Exchange Property-ZFLAG_APPLICABLE_VALUES value exists in exchange property-ZFLAG_ACTUAL_VALUES.
- Step 3.1 : If Yes, pass it to main mapping in default route where IDOC-External Definition mapping is done (Default Route)
- Step 3.2 : If No, end that IDOC in CPI (Condition : ${property.ZFLAG_ACTUAL_VALUES} not contains ${property.ZFLAG_APPLICABLE_VALUES}
  Figure 15 – Router Configuration
Step 4 : Mapping as applicable

IDOCs%20having%20atleast%20one%20ZFLAG%3DA

Figure 16 – IDOCs having atleast one ZFLAG=A sent to default route

Positive%20test%20Case%20%3A%204%20IDOCs%20triggered%20in%20a%20batch%2C%202%20have%20no%20line%20items%20with%20ZFLAG%3DA%20and%202%20IDOCs%20have%20mixed%20values

Figure – IDOCs having no ZFLAG=A ended in CPI

Simulation Results for Negative test Case : When none of the IDOCs in a batch have line items with ZFLAG=A

No%20IDOCs%20in%20a%20batch%20contain%20line%20items%20with%20ZFLAG%3DA%20ended%20in%20CPI

Figure 17 – No IDOCs in a batch contain line items with ZFLAG=A ended in CPI

Summary

Multi-dimensional approaches/ideas were shared for a requirement to bifurcate data based on repetitive XPath as explained above.

Hope this blog was informative with respect to the ideas on approaching a requirement with different ways and will be relevant to the CPI/PI/PO Developers/Consultants.

Constructive comments or feedback/suggestions if any on the above are welcome.