Question
Source as Data Page for PageList Property
If we create a Page List, in the property rule form, we have the Option source the Data Page, this is available as part of Pega7 Platform. If we leverage this option, there may be chance of Data Replication
For example If the Data Page is <D_Employee>
D_Employee.pxResults(100) – 100 Records , Developer is copying 100 records to Data Page
Pega is copying Data Page to PageList at the back, now the data is available in both of the entities looks like data duplication
If my requirement is to display data then I will prefer Data Page, if it persists with case then I will go by PageList , but not both
If it is parameterized Data Page, it reloads every time when Param changes, this causes the PageList Recopied, but data looks like replication. Here there is no pointers concept like C/JAVA data is available at one Place and refer to this from many places. The same thing happens for Property of Mode Single Page
{
String Str1 = “Hello World”;
String Str2=Str1;
}
Here String is stored only in one place and str1, str2 refers to same string , no duplicates
Why does Pega introduced this Option. Does this behave like R-D-E (Declare Expression)
***Moderator Edit: Vidyaranjan| Updated Categories***
How does this feature Advantages outweigh disadvantages
"If my requirement is to display data then I will prefer Data Page, if it persists with case then I will go by PageList , but not both"
-In both the cases Data Page can be used.
"Here there is no pointers concept like C/JAVA data is available at one Place and refer to this from many places."
-There is a concept as pointer in PRPC called as 'reference property'. A property can be referenced if 'Allow use as reference property in activities' is selected in advanced tab of the property. And later you can use 'Property-ref' method to relate two properties.
Reference property can be used if you want to relate a property to another property where both properties are in same top-level page or are in different top-level pages. Reference property can be used instead of copying another page.
"Does this behave like R-D-E (Declare Expression)"
-Data pages behave declaratively.
My question is very clear, why does Pega keeps data on two enties one is Data Page and other is PageLIst/Page prop.
Go with Page List if data needs to persist with case , otherwise prefer Data Page, but not both
Kavileswar, Reference of data page is only like pointers as pointed above. The benefit is you can access the page list using Top or Primary keywords. So defining pages in the pages and classes would be avoided making it easier to access.
Another, benefit of that it does not create two memory instances. The one in the top level page is only reference. You can have a look at the pyAttachmentlist property which refers to a data page on the attachment class.
The idea of the Data page is to display the fields for read only purpose. We have something similiar to pointers where u use the method property-ref to relate two properties.
If your intention is to edit it then just load it manually into a pagelist and edit the record.
Are you sure Pega is copying the data from the D_Page into a pagelist for this time of processing?