Modeling a Combo Engine 
Use
You use this procedure to model a combo engine that provides a record set to the associated property of a business object. This record set contains a list of values that appear at runtime in a field that is associated with the property of the business object. In addition, you can apply filters on the combo engine. These filters enable the record set to retrieve values that match a specific requirement.
You can create three types of combo engines such as Simple, Hierarchical Choice List, and Regular Choice List combo engines. The Simple combo engine allows you to define the type of record set that the system has to retrieve based on your requirements.
You may define the choice list tables using the Mobile System Maintenance application. If you want the system to retrieve a record set from these Choice List tables, then you can create a combo engine of type, Hierarchical Choice List or a Regular Choice List. The system provides the required values, and applies standard filters when you attempt to create a these types of combo engines. Therefore, you need not specify any values to model this type of combo engine. However, you need to apply custom filters.
Prerequisites
You have:
...
· Identified a specific BDoc, the corresponding segment and parameters that you need to use, if you want to create a Simple combo engine.
· Defined the choice list tables using the Mobile System Maintenance application, if you want to create a combo engine of type, Hierarchical Choice List or Regular Choice List.
· Identified the table that is associated with the BDoc you want to use for the combo engine.
· Synchronized the latest metadata of BDoc types on your Mobile Development Workstation from the BDoc Repository. (See, Synchronizing BDoc Changes.)
Procedure
1. In Solution Explorer, click the Combo Engines node with the secondary mouse button and choose New.
The Add Object window displays templates specific to various types of combo engines.
2. Choose the required template.
3. In the Name field, replace the default name of the combo engine with a meaningful name.
4. Choose Open.
The Combo Engine Designer appears.
If you want to create a combo engine of type, Hierarchical Choice List or Regular Choice List, continue with step 7.
5. Enter values for the fields that are listed in the table below.
Field name |
Value |
Additional information |
BDOC Name |
Name of the BDoc |
|
BDOC Segment |
Name of the segment modeled for the specified BDoc |
Combo engine uses this BDoc segment to retrieve a record set from the user database. |
Short Text Field |
Table field name that contains the short text values |
For example, SHORT_TEXT field that holds the short text values such as USA, JPN and IND for the COUNTRY property. |
Long Text Field |
Table field name that contains the long text values |
For example, LONG_TEXT field that holds the long text values such as United States of America, Japan and India for the COUNTRY property. |
Default Long Text |
A long text value that has to be displayed by default at runtime |
For example, “United States of America”, as a default value for the COUNTRY property. |
6. Enter values for the standard filters that are listed in the table below.
Field name |
Value |
Additional information |
Country Name |
Name of the table field that holds the country names |
|
Client Name |
Name of the table field that holds the client names |
|
Language Name |
Name of the table field that holds the languages in which application user can use a mobile client application |
|
Short Text |
Table field name that contains the short text values |
|
7. Enter values for the custom filters that are listed in the table below.
Field name |
Value |
Additional information |
Filter Type |
Static or Dynamic
|
· Static - record set is filtered based on a table field value. · Attribute - record set is filtered based on the value specified for a specific business object property. |
Filter Value(Static Value/BO Property) |
· A static value if you choose the Filter Type as Static · Name of the business object property if you choose the Filter Type as Dynamic |
· If you choose the Filter Type as Static, then you must specify a static value; for example, “Frankfurt”. Then combo engine retrieves a record set that contains records related to the city, “Frankfurt”. · If you choose the Filter Type as Dynamic, then you must specify the name of the property; for example, “CITY”. Then combo engine retrieves a record set that contains records based on the city name specified in the CITY field by the application user at runtime. |
In Memory Filter With |
BDOCSegmentField or BDOCParameter |
BDOCSegmentField - This filter is applied while combo engine retrieves the record set. BDOCParameter - This filter is applied after combo engine retrieves and stores the record set in memory. |
BDoc Parameter/BDoc Segment Value |
Name of the BDoc parameter or the BDoc segment value that need to be used to retrieve the record set |
|
8. In the Properties window, enter values for the fields that are listed in the table below.
Field name |
Value |
Additional information |
Cache Recordset |
True or False |
If you set the value as True, then combo engine stores the record set in memory only after retrieving it from the user database for the first time. |
Treat Zero As Blank |
True or False |
If you set this value as True, then combo engine determines whether or not the zero value that is entered by the application user need to be considered as a blank value. |
Use Optimizations |
True or False |
If you set the value as True, then combo engine reuses the record set that is stored in memory. Use this option to avoid the BDoc segment to retrieve the record set again, which is already available in memory. This option is available only if you select the Cache Recordset option. |
9. Choose Save.