I'm working on a program witch creates Business Partners in SAP IS-U system. For the creation of business partners I use function module BAPI_ISUPARTNER_CREATEFROMDATA
I have to add homepage URL too, any idea how to do it?
Thanks!
The homepage URL is part of the business partner's communication data, which can either be part of the address data or address-independent communication.
Look at function modules BAPI_BUPA_ADDRESS_ADD/BAPI_BUPA_ADDRESS_CHANGE for updating it with address data (table parameter BAPIADURI) or function modules BAPI_BUPA_CREATE_FROM_DATA/BAPI_BUPA_CENTRAL_CHANGE for address-independent communication, table parameter URIADDRESSDATANONADDRESS.
Unfortunately I do not have access to function BAPI_ISUPARTNER_CREATEFROMDATA to see if it has similar parameters.
Whether or not it must be stored as address-dependent or independent data is a business decision.
As an alternative, you should see whether you can update/create BPs via the BOL.
Related
My company has a service-oriented architecture. My app's GraphQL server therefore has to call out to other services to fullfill the data requests from the frontend.
Let's imagine my GraphQL schema defines the type User. The data for this type comes from two sources:
A user account service that exposes a REST endpoint for fetching a user's username, age, and friends.
A SQL database used just by my app to store User-related data that is only relevant to my app: favoriteFood, favoriteSport.
Let's assume that the user account service's endpoint automatically returns the username and age, but you have to pass the query parameter friends=true in order to retrieve the friends data because that is an expensive operation.
Given that background, the following query presents a couple optimization challenges in the getUser resolver:
query GetUser {
getUser {
username
favoriteFood
}
}
Challenge #1
When the getUser resolver makes the request to the user account service, how does it know whether or not it needs to ask for the friends data as well?
Challenge #2
When the resolver queries my app's database for additional user data, how does it know which fields to retrieve from the database?
The only solution I can find to both challenges is to inspect the query in the resolver via the fourth info argument that the resolver receives. This will allow it to find out whether friends should be requested in the REST call to the user account service, and it will be able to build the correct SELECT query to retrieve the needed data from my app's database.
Is this the correct approach? It seems like a use-case that GraphQL implementations must be running into all the time and therefore I'd expect to encounter a widely accepted solution. However, I haven't found many articles that address this, nor does a widely used NPM module appear to exist (graphql-parse-resolve-info is part of PostGraphile but only has ~12k weekly downloads, while graphql-fields has ~18.5k weekly downloads).
I'm therefore concerned that I'm missing something fundamental about how this should be done. Am I? Or is inspecting the info argument the correct way to solve these optimization challenges? In case it matters, I am using Apollo Server.
If you want to modify your resolver based on the requested selection set, there's really only one way to do that and that's to parse the AST of the requested query. In my experience, graphql-parse-resolve-info is the most complete solution for making that parsing less painful.
I imagine this isn't as common of an issue as you'd think because I imagine most folks fall into one of two groups:
Users of frameworks or libraries like Postgraphile, Hasaura, Prisma, Join Monster, etc. which take care of optimizations like these for you (at least on the database side).
Users who are not concerned about overfetching on the server-side and just request all columns regardless of the selection set.
In the latter case, fields that represent associations are given their own resolvers, so those subsequent calls to the database won't be fired unless they are actually requested. Data Loader is then used to help batch all these extra calls to the database. Ditto for fields that end up calling some other data source, like a REST API.
In this particular case, Data Loader would not be much help to you. The best approach is to have a single resolver for getUser that fetches the user details from the database and the REST endpoint. You can then, as you're already planning, adjust those calls (or skip them altogether) based on the requested fields. This can be cumbersome, but will work as expected.
The alternative to this approach is to simple fetch everything, but use caching to reduce the number of calls to your database and REST API. This way, you'll fetch the complete user each time, but you'll do so from memory unless the cache is invalidated or expires. This is more memory-intensive, and cache invalidation is always tricky, but it does simply your resolver logic significantly.
So this backend will be consumed by an ad-hoc front end application. But will also be integrated by other systems and we will expose API for them.
When designing the rest I see that there is ONE database table (we call it for table A) that can join many other tables, lets say about 10 to 20 other tables.
Now, my strategy would be to build routes in my backend that will "reason" according to the ad-hoc frontend we have.
So if there is a page in the frontend (let's call this page for page1) that requires to get rows from the table A but also fields from let's say 3 other join tables, then I want to create a route in the backend called maybe "page1" which will return rows from table A and also from the other 3 tables.
This is of course an ordinary way to build a backend. But as it will also be used by other systems then somebody could argue that these systems maybe don't have any need for the route "page1". Their frontend will maybe never build a "page1".
So according to people here, it would better to build the API more agnostically. And instead of creating the route "page1" I should build it according to "hateoas". And if I understand that principle, instead of letting my ad-hoc frontend to request the resource "page1" it would request "pageForTableA". And then, the resource "pageForTableA" should return which are the possible table to be joined.
In this case, for my frontend's page1, I would need to make 4 subsequent request to the server, instead of one like I would like to do if there was a "page1" resource in the backend.
What do you think?
I also see a thirt strategy. I don't know if there is a name for this pattern but it would be this way:
A resource in backend that returns only rows from table A. BUT, the route also takes arguments. And the argument is an array with the name of all the other tables someone want to include.
So if frontend calls:
getTableA(array('tableB', 'tableD', 'tableF'))
Then the resource would include/join the tables B, D and F. In short: API resource let's the frontend decide what it want to get delivered.
Which of these 3 strategies are best do you think? Or there is some more that could be taken in consideration?
You need to architect your API in a way that consumers shouldn't know about how the data is stored in the underlying data store.
Furthermore, if you want to allow consumers to decide which fields you want to project in the response, you could give them using some query string format.
BTW, maybe you should avoid re-inventing the wheel. There's a standard called Open Data (OData) which already defines a lot of things like you already require in your API, and since it has been made by Microsoft, it has deep support on .NET.
Check this tutorial (Create an OData v4 Endpoint Using ASP.NET Web API 2.2) to get more in touch with OData.
We have an app which is exposing a RESTful API to a UI for purchasing an item. I have a question regarding API design. Lets say the following action should be taken in order
Item to be chosen for purchase
Next give the address to be delivered to
My question is: should we design a single API which gets both data perform both? Or should we design two API calls - one that creates a purchase record and second that update the address to be delivered to?
The recommended SOA approach is to choose coarse-grained services, which would seem to argue the minimum amount of API calls.
However, from a business point of view, item selection and purchase and item delivery are two very different concerns that should be separate components in your architecture. For item selection, you need to consider things like inventory and pricing. For delivery address, you need to consider user address lists, address validation, shipping, and taxation.
Those two components are not likely to interact much except maybe some external association between an item id and address id. For this reason, I'd recommend two API calls. Functionally, this would also allow your API users do things like update the delivery address without re-purchasing an item, send the bill to one address and the item to another address, etc.
As you state that you design a RESTful API you usually start by designing resources instead of the intended calls. Later on, resource representations can be chosen that include other resources for optimised HTTP request counts.
You might want to choose to proceed the following way:
Model the item list resource (GET - lists all items, POST - allows item creation) /items/
Model the address list resource /addresses/
Model the item instance resource /items/item/resourceId
Model the address instance resource /addresses/address/resourceId
Now all of your resources are available you can think about usage patterns. All your resources are generically available and can be mashed up.
Possible approaches to answer your questions would be:
Extend the item instance resource with the needed address details (coarse grained as lreeder stated)
Model a resource /deliverydetails/ as list and instance resource containing item(s) and address, make the deliverydetails to be queried by item id or whatever your use case fits best
Hope that helps!
Btw. you are automatically following SOA approaches with a Resource Oriented Design. Interfaces will be naturally fitting your business requirements and generic enough to support more advanced use cases.
Here is a good example
EDIT: I've solved my issues (for now at least).
I've recently been working with the Zendesk REST Api and their use of the custom "X-On-Behalf-Of" header for looking up tickets opened by a particular user got me thinking about Restful Api design choices (in no specific language, more of a how to name URIs question). I've also read this related question on Custom HTTP headers, but it left me with more questions than answers.
Say I have an example restful web service dealing with rental apartment applications where clients use Basic Auth (keep it simple) to authenticate. Define the basic data as such:
Users (can be of type landlord or renter)
Forms (which consist of one or more Document resources and some form meta data like form name and version info)
And then some type of resource corresponding to Rental Applications, which ties together Forms, Applicants (one or more renters), Landlord, and some metadata like status and dates.
I'm struggling to properly model the URIs for the Applications resource in general, and more specifically with respect to a clients role. (assume api root is https://api.example.com/)
How do I allow a Landlord to fetch a list of applications sent to them? My intuition says make a request to "GET /applications" and Basic Auth lets the server know which user to build the list for; likewise "GET /applications" requested by a Renter would return a list of applications they've sent...but I'm not confident this is a solid design in general to mix and match sender vs. recipient lists at the same URI. Should I be thinking about the "/applications" resource differently, and perhaps allowing a hierarchy like "/applications/[USER_IDENTIFIER]" for each user instead?
Also, regardless of my applications URI design, assume a Landlord is able to create an application on behalf of a renter. Is this better accomplished by sending a custom header like "X-Create-On-Behalf-Of: somerenter#example.com" with the PUT/POST creation request? Or should my schema define a field which allows for this alternative scenario.
I'm very much an amateur at this, so I'm open to any criticism of my assumptions/design, as well as any pointers for learning more about designing RESTful api's. Thanks for reading.
I think I've found a solution.
Landlords and Renters are really just subclasses of the same object, which I'll call Party (as in party to a transaction, not birthday party). So then each one has their own resource, named like /party/PARTY_ID.
It's easy to extend this to see that /party/SOME_LANDLORD/applications and /party/SOME_RENTER/applications solve my issues. It also removes my need to consider custom headers.
Let's pretend we're talking about an HTML complaint form, one field of which is a product list from the company catalog.
I gather that validation usually (always?) goes in its own class.
I also gather that it's good practice to have gateway classes which can handle all the database queries internally, so when I save my complaint from my complaint form I don't have to worry about the database details.
But what about validation that requires accessing the database - for example checking that the product is actually a product we have (and not someone tampering with the form). This can only be done by finding a match in the database... but my database is abstracted behind my gateway.
Do I add validation logic to my gateway? Do I create validator gateway classes? Do I empower my validator with database logic?
EDIT - attempt to clarify...
customer clicks link to complaint form
HTML complaint form is built with a <select><item></item></select> dropdown with X products from our fictional company catalog
Customer completes form and Submits // Wiseguy alters HTML so product is "Schweddy Balls" and submits
Form class validates simple things like date, all required fields have data, email address, etc.
at step 4, in order to validate that the product being complained about is legit, you'd have to hit the database's product table to see if it's still a valid datapoint. Should that logic go in the form class, the gateway class, or somewhere else? putting it in the form class breeds dependencies, does it not?
Validation should, oddly enough, not be done directly through a Validation class. A model object's class (in this case probably Complaint) should include the Validation class and the validations should be done in there. Since the Complaint has access to all Complaints, validation methods can use the methods of the Complaint class, or call another model class if needed.
When you say "gateway" to the database, I believe you're talking about on Object Relational Mapping (ORM), which allows model objects, like a Complaint, to abstractly talk to the database. The ORM should have no knowledge of the structure or specifics of the application, it should only be an abstract API for objects to communicate to the database or other backend.
Surely my response does not cover everything, so further questions/clarifications welcome.
It's usually good practice to store valid data, only. So, one necessarily writes a validator on the server-side to ensure that requests are valid and only valid data gets put into the database, and as an optimization one typically validates on the client side (e.g. in JavaScript) so that the user is informed of invalid input without needing to submit the form and without needing to make a roundtrip. Doing the validation as part of the database write, allows subsequent reads to be done trivially with no checks.
I don't know the specifics of what counts as "valid" for you, but you can probably save a lot of database lookups with caching. Perhaps you could give some more information about your requirements?