meta data ,model data Model node,Value node & Adaptive RFC

[Former Member]

Dear All,

I have few questions?

1) What is difference between meta data and model data?

2) What is difference between Model node and Value node?

3) Why Adaptive RFC named "Adaptive"?

[saraswathi_d · Accepted solution]

Hi,

1. Model data --->Data dictionary of the model

eg: simpletypes, structures etc of the model

Meta data --->data about the component

2. Model node---> which is mapped from used models

Value Node---> Which is created by the user.

3. Adaptive RFC--> The aRFC layer is adaptive not dynamic.Thats why the name called adaptive RFC.

This new RFC model shows adaptive behavior. This means that the RFC proxies do not use the original design time structure definition at runtime. Instead, this Web Dynpro model automatically adapts the data of the structure passed in the Java proxy generation to the current data – that is, a structure definition in the back-end system that may have been modified

First the RFC layer was only accessible from C programs. The JCo layer was later added to give the java language access to the RFC layer.The aRFC layer will automatically update the dictionary with any metadata changes, but it is up to you to design your Web Dynpro application to react to these changes!

Regards,

Saraswathi

Message was edited by: Saraswathi D

Message was edited by: Saraswathi D

[Former Member]

Hi Vijit,

i need some brief details about meta data and model data.

Thanks & Regards

Manoj

[Former Member]

Hi Manoj,

Take the example of a RFC which gives the result in a table.

Then we can say that model data is the data coming through the table whereas metadata is the structure of the table.

Meta data is the data about data. Metadata contains structure definitions, type definitions etc.,

Hope it is clear.

Thanks & Regards,

Vijith

[Former Member]

The RFC in WDF is said to be Adaptive because of SAP's append structure functionality ie if you add a few fields in some structure of RFC which has been imported in your Web Dynpro Model, these new fields can be accessed at run time without reimporting the model. Hence the RFC is termed as Adaptive RFC in WDF.

Regards

Kapil

[Former Member]

Hi Manoj,

1) What is difference between meta data and model data?

A) Model data is the application data itself whereas metadata includes structure definitions and types.

2) What is difference between Model node and Value node?

A) Value nodes saves the data itself, whereas the model node only references an external model that saves the data.

3) Why Adaptive RFC named "Adaptive"?

A) Adaptive RFC call is a technology that allows WD developers to work with BAPI even after a structure modification.The RFC proxies do not use the original design time structure definition at runtime. Instead, this Web Dynpro model automatically adapts the data of the structure passed in the Java proxy generation to the current data – that is, a structure definition in the back-end system that may have been modified. This is the reason why it is called adaptive.

Refer the following link :

http://help.sap.com/saphelp_erp2005vp/helpdata/en/41/38bc8f813719488ddc9d9b21251ec3/frameset.htm

Regards,

Vijith

[Former Member]

As per my understanding,

Model Data is application data which sought from the back-end and Meta Data (data about data ) like dictionary - Simple types, structures etc..

Regards

Kapil

[Former Member]

Hello Manoj..

Difference b/w Model Node and Value Node :

A value node is the most basic form of node that can exist within a WDF. It maintains its own element collection with each element in the collection holding the actual runtime data.

A model node is similar to a value node in respect to its API however there are few differences :

1. A context model node makes a model object look like any other context node

2. A model node is not considered valid unless it is bound to some model object.

3. The element collection in a model node does not hold the actual runtime data, instead it holds a collection of references to the relevant model object instances..

Regards

Kapil