8/13/2019 Singleton Context Nodes - Web Dynpro ABAP

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Web Dynpro ABAP - Singleton Context Nodes RevisitedThomas Sz !sB"siness CardCompany# !bs $nternehmensberat"ng %mb&Posted on De!' ()* +,, ,.#./ A0 in ABAP * Appli!ation Server * Beginner *SAP

NetWeaver Plat1orm * Web Dynpro After writing the blog about the usage of singleton context nodes in Web Dynpro ABAP, I received some questionsby email !ince I found them useful in a sense that other developers might have similar questions, I would li"e tota"e the opportunity to answer them in blog

#$ %ou mentioned that certain ui elements &e g the 'ree( don)t wor" with singleton nodes 'o me this sounds li"e abug If so, why don)t you fix it*

A$ +irst off, it)s not a bug Actually, the context behaves exactly as it was set up and according to how singletoncontext nodes are expected to behave 'he tree displays this context structure perfectly as well et me explain iton an example I am aware that it has its shortcomings, but I believe it describes the situation quite well from abeginners perspective -sing a tree ui element together with singleton context nodes is a bit li"e flagging a numberof classes as static and trying to display them as a tree 'he result will always be a line or a tree that behaves asdescribed in the other blog, because there is only a single .instance. for each type of entity

#$ Will you enhance the design time chec"s to detect combinations of ui elements and singleton nodes that don)tgo along very well*

A$ We are constantly improving the design time chec"s to ma"e it easier and more convient for developers tocreate Web Dynpro ABAP applications !o the answer is clearly a yes

#$ What is the suggestion* !hould I switch the singleton flag off or on*

A$ If you are a beginner or uncertain about if singleton context nodes are benefitial for your scenario, it)s best toswitch off of the flag

#$ Are you deliberating to change the default in the wor"bench*

A$ %es, although there is the compatibility issue, which we have to ta"e care of 'his means that we are loo"ing forways to change the default, but at this moment can)t definitely confirm that we will be able to change it

#$ Is there any situation where using singleton context nodes ma"es sense*

A$ /f course0 !uppose you have a context with a very large number of nodes nested in a deep hierarchy -singsupply functions and having a user who accesses a large portion of the tree while wor"ing with the application willlead to effect that the memory consumption of the application will increase over time In case there is a memorybottlenec" at the application server &i e due to many users doing the same thing(, using singleton context nodescan improvde the performance 'his is something one should test though by comparing both versions of anapplication and then ma"e a decision on the data gathered

I hope, this answers some of the questions

Thomas Szücs is a Senior Solution Architect for cbs Corporate Business Consulting GmbH

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!howing messages 3 through 3 of 3

'itles /nly 4ain 'opics /ldest +irst • 4emory consumption and the WDA tutorial supply functions

5667835839 36$5:$37 David ;alits"y Business <ard =2eply>

;i 'homas 8

I thin" it)s great you ta"e the time on stuff li"e this Again, part of what I meant in my post today about the.privilege. of wor"ing with !AP

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8/13/2019 Singleton Context Nodes - Web Dynpro ABAP

http://slidepdf.com/reader/full/singleton-context-nodes-web-dynpro-abap 2/2

I note, however, that in some of the tutorials, the supply functions wor" as if a tree can always be filled .to the lastdrop. without a problem

'his was not the case in the older ABAP // tree examples, which were very careful to stress not to fill the tree tomore than depth 3 for the first display

Dave