OVS usage

[former_member184112]

Hi,

I know ovs is mainly used for dynamic search helps...

we use it when you dont have any direct input help for an attribute.

I have a question, Can we use OVS even if you have direct input help. Why because for performance wise OVS is better than direct help. I think Am i right?

Thanks and Regards,

Prabhakar Dharmala

[Former Member · Accepted solution]

You can use OVS even if you have a dictionary search help, because

- Using OVS, you can easily capture the selection event, which you cannot in the ddic help. Depending on the selection if you want any conditional code to execute, it is simple with OVS.

- OVS is customizable - since you build the input help table at runtime, you can display selective values.

I am not sure of the performance factor.

Regards,

Nithya

[Former Member]

Using the OVS is based mainly on the following three steps:

...

1. OVS helper context: The OVS stores its data (search input data and the query results)

in an OVS helper context, which is part of the OVS custom controller. The application

developer declares a context node of cardinality 1..1 for storing the search input data

and another node of cardinality 0..n for storing the query results. If a suitable RFC

function is available, you just have to declare the model binding. The input and output

node are then part of the created context structure.

2. OVS listener: The OVS uses a listener implementation of the interface

IWDOVSContextNotificatiionListener. This listener implements three hook

methods, which act as event handlers and are called at three separate points in time:

When the OVS UI is requested for a field, when the search query is triggered, and

when the user selects a row in the search result table (see figures below).

3. OVS extension: The OVS is used for finding objects and copying object values to the

context (to context attributes). It is an input help service provided for all context

attributes (that is, input fields bound to these context attributes), which were

programmatically extended with the OVS feature. The Web Dynpro programming

model API provides the WDValueServices class for adding this OVS extension to

context attributes.

[Former Member]

Yes. You can use OVS even you have the Default input help. This you can do by changing the Porperpty of Atrubute in the context.

Just open the Attrubute properties of your context. Change the Input Help mode from "Automatic" to "Object Value Selector" then it will work fine

Warm Regards,

Vijay

[former_member184112]

Hi All,

Do you know performance wise which is the best.

Because we have developed without OVS but we are facing slow perforamnce of search helps in our applications.

Shall we go to use OVS for improve performance.

Thanks and Regards,

Prabhakar Dharmala

Edited by: Prabhakar Dharmala on Jun 11, 2008 5:59 PM

[Former Member]

Typically, how many entries will you be displaying in the search help? In the case of OVS, if you have a pre calculated list of entries in an internal table (say in view attributes) and you display those, it might improve performance. But generally in OVS, the search help itself is built at runtime. This would mean firing select queries on DB tables only after pressing the F4. This would definitely not improve performance, especially if there are a large number of entries.

Regards,

Nithya