Hello
My name is Oliver Schmidt, I'm a CS Student and currently writing my bachelor thesis in which i evaluate SAPUI5 and AngularJS as Front-End Framework for the development of User Interfaces on the SAP Hana Cloud Platform. Now you may ask: what are my reasons to even use a third party framework for the HCP:
Why use another Frontend JavaScript?
According to an often cited Definition for the Platform-as-a-Service (PaaS) Cloud Service Model by the U.S. National Institute of Standards and Technology (NIST) applications on these platforms are "...created using programming languages, libraries, services, and tools supported by the provider."http://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-145.pdf
In this case the Javascript Framework supported by the provider without a doubt is SAPUI5. In the Source of the Quote i just used is an interesting footnote. It says "This capability does not necessarily preclude the use of compatible programming languages, libraries, services, and tools from other sources"
This means that as a developer i am not tied to use SAPUI5 on the HCP.
This is where my motivation comes from to try out other Javascript Frameworks. Now the question is what are these "compatible languages, libraries (and without a doubt also frameworks) from other sources". The bold word marks the interesting part. What extactly makes a framework compatible to the HCP?
Before i go into this question i want to talk about another topic. Why did i chose Angular JS as comparable framework for my thesis.
Checking the Github frontent javascript ranking i saw AngularJS sticking out as most forked and starred framework. This shows how widely used AngularJS is and the sheer number of forks that it can be the base for so many more Projects. I figured it is the most adaptable and expandable framework.
Now back to the interesting question.
What makes a javascript framework compatible to the HCP?
To make a framework compatible to a Platform ist that the framework leverages all the features provided by the Platform.
I'm aware that AngularJS won't exactly cover all of the Use Cases that SAPUI5 covers out of the box but i'm positive that AngulaJS lets me do things different and maybe even simpler than SAPUI5. A week after i started preparing for the thesis SAP uploaded an example how to use AngularJS to access an OData Service on the HCP.https://github.com/SAP/cloud-angularjs-sample
I'm grateful for that since this proof of concept showed me that it is possible to use Odata Services and Destinations in general with AngularJS without writing miles of code.
OData is used in almost all tutorials of SPAUI5 and from that (and also by having read the documentation of the HCP) i figure that easy access to Odata should be part of a javascript framework that will be used on HCP. But what else?
I identitifed four general Topics where SAPUI5 excells, which can be splitted into smaller problems. SAPUI5 was built for these topics but it took me long hours to learn it since SAPUI5 seems complicated but also very powerful. These things are all part of the HCP's three use case Scenarios (Extending Cloud Apps, Extending On-Premise Applikations and Building Cloud Apps)
- GUI Elements
Tables, Lists, Buttons and all other GUI Elements that make the Data fetched from the Backend Service readable. Since SAPUI5 elements are integrated into the model,when i include paging in a table element then it automatically adapts the OData call to only fetch e.g 5 Elements instead of the whole table. This tight integration is where SAPUI5 really shines.
- Theming/Design
SapUI5 offers for almost no work really beautiful and nice looking websites. If you follow any SAPUI5 Tutorial you see apps that are clear and crisp in design. Using the angular example from Github i get a white Website since Angular lacks the automatic css styles and style ements that are included into SAPUI5. Including it will be additional development effort. Just like changing the standard design from SAPUI5.
- Destinations
In this case especially Odata Services. Things like Two Way Binding for Odata Models and usage of filters, grouping and all the useful OData Queries without having them to chain to the link of the service.
- An Architecture Model
Doesn't matter if it is SAPUI5s MVC Model oder Angulars MVVM Model. Architecture Models help to build more readable and extendable Front End Applications in general.
Besides functions like that, documentation plays a big part while chosing a framework. SAPUI5s documentation is a bit overwhelming at first but the sapui5 Explored Page is amazing and with the OpenSAP Course about SAPUI5 i got a good introduction.
Now i just want to make a short survey in the community which features of the HCP should be supported by a framework without much adjustment to be an alternative for SAPUI5. Since my experiences with the HCP is broad (thank you OpenSAP) but purely theoretical i want to ask people who use the HCP in a real development and deployment environment.
TL,DR: What features does a Javascript Framework need to have so it would be attrictive to use on the HCP?