what is a context ?, what is a node ? in web dynpro for ABAP -
Context :
Context is a temporary place where we declare data deceleration's in the form of nodes and attributes.
Attribute :
It is used to store a single value, these are similar to fields in table or structure.
Ex: MATNR, MTART, VBELN
Node :
Node is a collection of attributes, it is similar to structure or internal table.
Properties of node
Cardinality :
It specifies how many records that can be stored in a node, four options are available under cardinality.
| Minimum | Maximum | Description |
|---|---|---|
| 0 | 1 | Node can store only one record i:e same as work area. Node can only be filled through back end logic only ( can not be used for user input ). |
| 1 | 1 | Node can store only one record I:e same as work area Node can be used for user input . |
| 0 | n | Node can store maximum 'n' number of records. Node can only be filled through back end logic only ( can not be used for user input ) |
| 1 | n | Node can store 'N' number of records I:e same as internal table Node can be used for user input .
If maximum value = 1, it can store 1 record.
If maximum value = n, it can store 'N' records.
If minimum value = 0, data is selected from back end (using select, itab etc).
If minimum value = 1, data can be selected from front end (user input). |
