xAPPnow LOW CODE PLATFORM - User Manual 

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Training Frontend Service - Call Element

 
 
Related subfolder of the training project: "Automation/Service/Training/Service/Exercise/CallElement"
 
 

Chapter Overview

 
In this training chapter you will get familiar with the call element as well as some further error handling concepts.
 
 
Features Call Element
 
  • a call element is used to link reusable service models
  • service models that are linked to a call element are not directly included into the parent service model and have to be published as a separate service model
     
    Remark: At runtime a service model that is linked to a call element, can be loaded directly, lazy or on demand.
 
 
 
 
 
 
 
  • a call element may receive child model error and therefore has up to three types of output flows
  • sequence flow (standard flow)
    2. error flow (business error)
    3. fatal flow (technical error)
     
     
     
     
     
     
  • TAB "Implementation" SubTAB "Error Configuration" of the call element
  • You can select the error type to activate the corresponding error flow or fatal flow, if the error is not handled in the child model
  • you have to map an error object to receive the output of the child model
     
  • You can implement "Error Script" or "Fatal Script", which are executed before the related output flow is triggered
     
     
     
     
     
     
Business Error End Event & Technical Error End Event
 
A service model can handle a business error or technical error by itself or propagate the error to the parent model using a "Business Error End Event" or a "Technical Error End Event"
 
 
 
 
 
 

Exercise - Call Element

 
In this exercise you should reimplement part of the client service models above to understand the usage of a call element and related error handling concepts.
 
The sample starts with a UI page to enter user registration data. Dependent on the age and the button "Check Database" or "Register" the different flow types of the call element are processed.
 
 
 
 
 
 
The registration result and the executed flow type are displayed in the second UI page.
 
 
 
 
 
 
 
Exercise 1: Create the Submodel "VerifyRegistration"
 
  • Step 1: Right click at model tree folder "Automation/Service/Training/Service/Exercise/CallElement" to open context menu "Create Model"
  • Step 2: Enter model name "VerifyRegistration" and set option "Model Type: Dynamic Frontend Service" in dialog "Create Frontend Service Model"
  • Step 3: Click button "Search" to open dialog "Select Template" to select model "TMPL_VerifyRegistration" from folder ".../Template/CallElement"
  • Step 4: Click button "OK" to create the model
 
 
 
Training Frontend Service - Call Element
 
 
 
Exercise 2: Complete Submodel "VerifyRegistration"
 
  • Step 1: Right click at script element "Check Database" and open the context menu to add a technical error end event "Technical Error".
  • Step 2: Select technical error end event "Technical Error" and open TAB "Implementation", SubTAB "Init Script" to enter script:
 
localData.genericError.isBusinessError = false;
 
 
Training Frontend Service - Call Element
 
 
  • Step 3: Open SubTAB "Configuration" and map "genericError" on Error Object textfield
  • Step 4: Right click at script element "Verify Age" and open the context menu to add gateway "Legal Age?" and move the label above the gateway
  • Step 5: Right click at gateway "Legal Age?" and open the context menu to add end event "End"
  • Step 6: Right click again at gateway "Legal Age?" and open the context menu to drag&drop business error end event "Business Error" below the gateway
 
 
Training Frontend Service - Call Element
 
 
  • Step 7: Select conditional flow of end event "End" and press F2 to enter label "YES" and move it to the middle of the conditional flow.
  • Step 8: Select conditional flow "YES" and open TAB "Implementation" to enter flow condition:
 
localData.moderationCriteria.hasReachedLegalAge == true
 
 
  • Step 9: Select conditional flow of business error end event "Bussiness Error" and press F2 to enter label "NO" and move it to the middle of the conditional flow.
  • Step 10: Select conditional flow "NO" and open TAB "Implementation" to enter flow condition:
 
localData.moderationCriteria.hasReachedLegalAge == false
 
 
 
Training Frontend Service - Call Element
 
 
 
  • Step 11: Select business error end event "Business Error" and open TAB "Implementation", SubTAB "Init Script" to enter script:
 
localData.genericError.isBusinessError = true;
 
 
Training Frontend Service - Call Element
 
 
  • Step 12: Open SubTAB "Configuration" and map "genericError" on Error Object textfield
 
 
Exercise 3: Create Parent Model "UserRegistration"
 
  • Step 1: Right click at model tree folder "Automation/Service/Training/Service/Exercise/CallElement" to open context menu "Create Model"
  • Step 2: Enter model name "UserRegistration" and set option "Model Type: Dynamic Frontend Service" in dialog "Create Frontend Service Model"
  • Step 3: Click button "Search" to open dialog "Select Template" and select model "TMPL_UserRegistration" from folder ".../Template/CallElement"
  • Step 4: Click button "OK" to create the model
 
 
 
Training Frontend Service - Call Element
 
 
 
Exercise 4: Complete Parent Model "UserRegistration"
 
  • Step 1: Drag&Drop a call element from the palette between UI Page "Request Registration" and Script "Business Error" and enter label "Verify Registration Data"
  • Step 2: Open context menu of call to set background color "orange"
     
 
 
Training Frontend Service - Call Element
 
 
 
  • Step 2: Draw button flow "Check" and button flow "Register" from UI page "Request Registration" to call element "Verify Registration Data"
  • Step 3: Draw a sequence flow from call element "Verify Registration Data" to script element "Standard No Error"
  • Step 4: Draw an error flow from call element "Verify Registration Data" to script element "Business Error"
  • Step 5: Draw a fatal flow from call element "Verify Registration Data" to script element "Technical Error"
 
 
 
Training Frontend Service - Call Element
 
 
 
  • Step 6: Select call element "Verify Registration Data" and open TAB "General", SubTAB "Element"
  • Step 7: Click button "Search" to open dialog "Select or Create Submodel" and select model "VerifyRegistration" from folder ".../Training/Service/Exercise/CallElement"
  • Step 8: Select call element "Verify Registration Data" and open TAB "Implementation", SubTAB "Error Configuration" to map error object "genericError" with "Error Object"
 
 
 
Training Frontend Service - Call Element
 
 
Exercise 5: Test the Model in User Portal
 
  • Step 1: Click button "Publish"
  • Step 2: Login into xAPPnow User Portal and open menu "Functions" to test this model
     
    Remark: An error message will be displayed, because the submodel "VerifyRegistration" is missing
     
     
     
     
  • Step 3: Double Click at call element "Verify Registration Data" to publish submodel "VerifyRegistration" into User Portal
  • Step 4: Login into xAPPnow User Portal and open menu "Functions" again to test this model
 
 
 
1

Select Template

1. Select Template
Click button "Search" to open dialog "Select Template" to select model "TMPL_VerifyRegistration" from folder ".../Template/CallElement"
1

Add Technical Error End Event

1. Add Technical Error End Event
Right click at first script element to open context menu and add a Technical Error end event.
2

Enter Init Script

2. Enter Init Script
Select the technical error end event and open TAB "Implementation", SubTAB "Init Script" and enter the following javascript code
1

Add Gateway

1. Add Gateway
Right click at second script element to open context menu and add a gateway with label "Legal Age?" and move the label to the upper side of gateway
2

Add End Event

2. Add End Event
Right click at gateway to open context menu and add an end event
3

Add Business Error End Event

3. Add Business Error End Event
Rigth click again at gateway to open context menu and drag&drop a business error end event below de gateway
1

Select Gateway Flow

1. Select Gateway Flow
Open TAB "Implementation" and enter the flow condition
1

Select Business Error End Event

1. Select Business Error End Event
Select the business error end event and open TAB "Implementation", SubTAB "Init Script"
2

Enter Init Script

2. Enter Init Script
Enter the following javascript code
1

Select Template

1. Select Template
Click button "Search" to open dialog "Select Template" to select model "TMPL_UserRegistration" from folder ".../Template/CallElement"
1

Drag&Drop Call Element

1. Drag&Drop Call Element
Drag&Drop a Call element from palette between the UI Page "Request Registration" and Script "Business Error" and enter label "Verify Registration Data"
1

Draw
Button Flows

1. Draw Button Flows
Draw two flows from UI page "Request Registration" to call element "Verify Registration Data", then select both button flow labels using context menu
2

Draw
Standard Flow

2. Draw Standard Flow
Draw a Standard Flow from call element to the script element "Standard No Error"
3

Draw
Error Flow

3. Draw Error Flow
Draw an Error Flow from call element to the script element "Business Error"
4

Draw
Fatal Flow

4. Draw Fatal Flow
Draw a Fatal Flow from call element to the script element "Technical Error"
1

Configure Error Object

1. Configure Error Object
Select call element and open TAB "Implementation", SubTAB "Error Configuration" to map BO "genericError" on field "Error Object"