Subscriptions in Paymill - paymill

A client with a subscription "Large" (recurring payment).
I create a payment and offer object for doing that, and it works.
Now I want to update that subscription to "Small" (a different name and amount) but without updating the credit card.
The paymill flow for doing this is very documented very vague and it's uncertain what the process is.
Have you done anything like this with Paymill, I would be happy to hear about what calls you are doing.
I am using the .NET wrapper

To change an offer (plan) of a running subscription there are 3 types you can use.
Here is the documentation: https://developers.paymill.com/en-gb/subscription-v2-workflow/#update-sub-plan
In .NET they are exposed with the three methods, that are documented:
ChangeOfferKeepCaptureDateAndRefundAsync
ChangeOfferKeepCaptureDateNoRefundAsync
ChangeOfferChangeCaptureDateAndRefundAsync

Related

How do I make free read-only calls to a smart contract on Hedera blockchain network without incurring charges?

The problem is that I am trying to make free read-only calls to a smart contract on the Hedera network, but am encountering unexpected results. I have tried various methods, but am unable to successfully make the calls without incurring charges. I am looking for a solution or guidance on how to properly make these free read-only calls to the smart contract on Hedera.
//Create the transaction
const transaction = new ContractExecuteTransaction()
.setContractId(newContractId)
.setFunction("get_message")
I expected this get_message to not charge me HBAR since that function just returns a hardcoded string but I cant execute it for free like I want to. How do I do this?
If you're using the SDK, using ContractCallQuery() is better suited for read-only queries. See sample below:
// Query the contract to check changes in state variable
const contractQueryTx1 = new ContractCallQuery()
.setContractId(contractId)
.setGas(100000)
.setFunction("get_message";
const contractQuerySubmit1 = await contractQueryTx1.execute(client);
Note that the SDK still requires some small amount of gas.
There are a couple of other ways to do cost-free queries.
Use mirror nodes. These two tutorials can give you additional information on working with mirror nodes: https://hedera.com/blog/how-to-inspect-smart-contract-transactions-on-hedera-using-mirror-nodes and https://hedera.com/blog/how-to-look-up-transaction-history-on-hedera-using-mirror-nodes-back-to-the-basics
If you use Hashio (https://swirldslabs.com/hashio/) as a JSON-RPC relay, then you can use EVM tooling to deploy and interact with contracts on Hedera. Then you can simply call contracts the way you would in a chain like Ethereum. Here are some examples: https://github.com/hashgraph/hedera-json-rpc-relay/tree/main/tools

How to organize endpoints when using FeathersJS's seemingly restrictive api methods?

I'm trying to figure out if FeathersJS suits my needs. I have looked at several examples and use cases. FeathersJS uses a set of request methods : find, get, create, update, patch and delete. No other methods let alone custom methods can be implemented and used, as confirmed on this other SO post..
Let's imagine this application where users can save their app settings. Careless of following method conventions, I would create an endpoint describing the action that is performed by the user. In this case, we could have, for instance: /saveSettings. Knowing there won't be any setting-finding, -creation, -updating (only some -patching) or -deleting. I might also need a /getSettings route.
My question is: can every action be reduced down to these request methods? To me, these actions are strongly bound to a specific collection/model. Sometimes, we need to create actions that are not bound to a single collection and could potentially interact with more than one collection/model.
For this example, I'm guessing it would be translated in FeathersJS with a service named Setting which would hold two methods: get() and a patch().
If that is the correct approach, it looks to me as if this solution is more server-oriented than client-oriented in the sense that we have to know, client-side, what underlying collection is going to get changed or affected. It feels like we are losing some level of freedom by not having some kind of routing between endpoints and services (like we have in vanilla ExpressJS).
Here's another example: I have a game character that can skill-up. When the user decides to skill-up a particular skill, a request is sent to the server. This endpoint can look like POST: /skillUp What would it be in FeathersJS? by implementing SkillUpService#create?
I hope you get the issue I'm trying to highlight here. Do you have some ideas to share or recommendations on how to organize the API in this particular framework?
I'm not an expert of featherJs, but if you build your database and models with a good logic,
these methods are all you need :
for the settings example, saveSettings corresponds to setting.patch({options}) so to the route settings/:id?options (method PATCH) since the user already has some default settings (created whith the user). getSetting would correspond to setting.find(query)
To create the user AND the settings, I guess you have a method to call setting.create({defaultOptions}) when the user CREATE route is called. This would be the right way.
for the skillUp route, depends on the conception of your database, but I guess it would be something like a table that gives you the level/skills/character, so you need a service for this specific table and to call skillLevel.patch({character, level})
In addition to the correct answer that #gui3 has already given, it is probably worth pointing out that Feathers is intentionally restricting in order to help you create RESTful APIs which focus on resources (data) and a known set of methods you can execute on them.
Aside from the answer you linked, this is also explained in more detail in the FAQ and an introduction to REST API design and why Feathers does what it does can be found in this article: Design patterns for modern web APIs. These are best practises that helped scale the internet (specifically the HTTP protocol) to what it is today and can work really well for creating APIs. If you still want to use the routes you are suggesting (which a not RESTful) then Feathers is not the right tool for the job.
One strategy you may want to consider is using a request parameter in a POST body such as { "action": "type" } and use a switch statement to conditionally perform the desired action. An example of this strategy is discussed in this tutorial.

How do multiple versions of a REST API share the same data model?

There is a ton of documentation on academic theory and best practices on how to manage versioning for RESTful Web Services, however I have not seen much discussion on how multiple REST APIs interact with data.
I'd like to see various architectural strategies or documentation on how to handle hosting multiple versions of your app that rely on the same data pool.
For instance, suppose you make a database level destructive change to a database table that causes you to have to increment your major API version to v2.
Now at any given time, users could be interacting with the v1 web service and the v2 web service at the same time and creating data that is visible and editable by both services. How should this be handled?
Most of changes introduced to API affect the content of the response, till changes introduced are incremental this is not a very big problem (note: you should never expose the exact DB model directly to the clients).
When you make a destructive/significant change to DB model and new API version of API is introduced, there are two options:
Turn the previous version off, filter out all queries to reply with 301 and new location.
If 1. is impossible to need to maintain both previous and current version of the API. Since this might time and money consuming it should be done only for some time and finally previous version should be turned off.
What with DB model? When two versions of API are active at the same time I'd try to keep the DB model as consistent as possible - having in mind that running two versions at the same time is just temporary. But as I wrote earlier, DB model should never be exposed directly to the clients - this may help you to avoid a lot of problems.
I have given this a little thought...
One solution may be this:
Just because the v1 API should not change, it doesn't mean the underlying implementation cannot change. You can modify the v1 implementation code to set a default value, omit the saving of a field, return an unchecked exception, or do some kind of computational logic that helps the v1 API to be compatible with the shared datasource. Then, implement a better, cleaner, more idealistic implementation in v2.
when you are going to change any thing in your API structure that can change the response, you most increase you'r API Version.
for example you have this request and response:
request post: a, b, c, d
res: {a,b,c+d}
and your are going to add 'e' in your response fetched from database.
if you don't have any change based on 'e' in current client versions, you can add it on your current API version.
but if you'r new changes are going to change last responses, for example:
res: {a+e, b, c+d}
you most increase API number to prevent crashing.
changing in the request input's are the same.

Adding to a property in a restful API

I am in the process of designing an HTTP API.
I have a Card resource which has an Balance property, which clients can add/subtract to.
At first I thought this should be implemented as PUT, because it's a form of Update to the resource, but then I read that PUT is idempotent, but adding to an amount isn't idempotent.
As it's not a creation of an object, I think I'm left with referring to it as a controller, something like:
POST example.org/card/{card-Id}/AddToBalance
data: value=10
will add 10 to the balance.
Is there a better way?
Yea, use cases like these are not where REST excels (expressing operations, particularly when they only affect a small subset of an entities data). Your particular case is pretty simple though, you can handle it with a slight change to your verb and endpoint:
PUT example.org/card/{card-Id}/balance
{"value" : 100}
Basically read as "Update the balance of card {id} to 100". On the server side you will still need to validate the transaction, and determine wether its a valid add based off the existing value of the balance.
Design Looks good as for as REST principals are concerned.
PUT action should be Idempotent. But it depends upon you requirement
Other thing you can use PATCH, as you are just doing partial amount of Updates rather than complete replacement of resources.

Multiple WCF service calls in ACID transaction

Here's my scenario: I need to make three or four calls to different WCF services before completing the transaction - what are my options, if any?
ServiceA.SaveWork(work1);
ServiceB.SaveWork(work2);
ServiceC.SaveWork(work3);
ServiceD.SendNotification(notification);
If one call fails, all fail... Note that these services may not be in the same domain.
Cheers!
You should be able to wrap those into a System.Transctions.TransactionScope to achieve this:
using(TransactionScope scope = new TransactionScope())
{
ServiceA.SaveWork(work1);
ServiceB.SaveWork(work2);
ServiceC.SaveWork(work3);
ServiceD.SendNotification(notification);
scope.Complete();
}
Of course, you need to make sure your WCF services don't explicitly prevent being part of a transaction! (check out the TransactionFlow attribute - avoid the TransactionFlow.NotAllowed setting!)
If these services are all on different machines etc, using two phase commit will lead to lots of real world problems.
Therefore I don’t think transactions are a good solution....
I think you need to make all your services so you can undo the work if needed to recover from an error. Undoing a item of work can be very complex in the real world.
E.g If you need to book a car and a hotel and then the hotel burns down, you can’t expect to be able to un-book the car without losing some money.
However if all the services sit on top of the same database, then transactions may work well for you.