Rest API path with many to many relationship - spring

I am defining a rest path for a many to many relationships.
I want to get a list of users which are guest of a company.
Is the path below sufficient?
/api/v1/users/companies/{companyId}/guests
Because I put it in UserController so it cant not be
/api/v1/companies/{companyId}/guests
Do you have any suggestion?

I primarily intended to write a comment, but it's the way too long so I've written an answer instead.
First of all, REST is an architectural style and not a cookbook for designing URIs. REST doesn't enforce any URI design (as long as it's compliant with the RFC 3986) and it's totally up to you to pick the URIs that better identify your resources.
Do you have any suggestion?
Answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise. What you'll read from this point is my personal opinion.
If the guests and the companies resources can be managed independently, I would use the following mappings:
/companies
/guests
Then you can use a query parameter to filter the guests for a given company:
GET /guests?company={id} HTTP/1.1
Host: example.org
To create a guest resource for a given company, you could use:
POST /guests HTTP/1.1
Host: example.org
Content-Type: application/json
{
"name": "John Appleseed",
"companyId": 1
}

REST doesn't care what spellings you use for your resource identifiers, so long as they are consistent with the production rules defined in RFC 3986.
/api/v1/users/companies/{companyId}/guests
That's fine
/api/v1/companies/{companyId}/guests
That would also be fine.
/d4158568-c40f-4c51-93cd-25642f6f42e2
So would that.
/api/v1/companies/guests?companyId={companyId}
On the web, you are perhaps more likely to see an identifier like this one; forms are a useful way of enabling a client to provide data, and HTML has production rules for creating a URI from data in a form. Of course, HTTP also has mechanisms that allow you to redirect the clients attention from one URI to another, so you don't have to restrict identifiers to those appropriate for a specific client.

Related

What HTTP Protocol can I use if I need to GET something from the server but I also need to send a requestbody?

I am using SpringBoot...
I can not use GET protocol and include a body, but I am not going to create or update anything on the server so I do not want to use POST or PUT, any other protocol that acts like a GET with body?
if you wonder what I need to send in that body it is an url parameter, like for example http://somewebsite.com/stuff/etc and I feel that putting this inside a request body is better than putting it as a requestparam
I can not use GET protocol and include a body, but I am not going to create or update anything on the server so I do not want to use POST or PUT, any other protocol that acts like a GET with body?
Your best bet, where suitable, would be to mimic how HTML forms work; which is to say having a family of resources with identifiers that are filled in by the client (in general, via URI templates -- often via query parameters as would happen with an HTML form).
When that's not appropriate: as of 2022-11, your best bet is POST. It's not a great answer (in particular, general purpose HTTP components won't know that the semantics of the request are safe), but it is the best option available of the registered methods.
POST serves many useful purposes in HTTP, including the general purpose of "
"this action isn’t worth standardizing." -- Roy Fielding, 2009
Eventually, the HTTPbis-wg will finalize the safe-method-with-a-body proposal, and at that point that will become a much better option than POST (for the cases that match the new semantics).

Defining right API endpoint REST/RPC

I am developing an API in a microservice for Invoice entity that takes in input a list of Purchase Order Item (i.e. PO Item) identifiers for ex. PO# + productIdentifier together can be used to identify a POItem uniquely. The response of the API is the invoiced quantity of each PO Item.
Input Model -
input GetInvoicedQuantityForPOItemsRequest {
poItemIdentifierList : POItemIdentifierList
}
Structures
list POItemIdentifierList {
member : POItemIdentifier
}
structure POItemIdentifier {
purchaseOrderNumber : String,
productIdentifier : Long
}
Invoiced Quantity of a POItem = SUM of Quantity of Invoice Items created from that PO Item.
Note : A single PO can be used to create multiple Invoices. An Invoice can be created from multiple POs.
I am quite new to REST and so far we have been using RPC endpoints in our legacy service. But now i am building a new service where i am defining endpoints in REST format (for ex. CreateInvoice has been changed to POST /invoice) and I need some suggestions from Stack Overflow community what would be the right approach for defining the REST endpoint of this API or should we keep it in RPC format itself.
RPC endpoint for this API in legacy system : POST /getInvoicedQuantityForPOItems
Our first attempt on REST for this is : POST /invoice/items/invoicedQuantityForPOItems. But this URI does not look like a Noun it is a Verb.
this URI does not look like a Noun it is a Verb.
REST doesn't care what spelling conventions you use for your resource identifiers.
Example: this URI works exactly the same way that every other URI on the web works, even though "it looks like a verb"
https://www.merriam-webster.com/dictionary/post
The explanation is that, in HTTP, the semantics of the request are not determined by parsing the identifier, but instead by parsing the method token (GET, POST, PUT, etc).
So the machines just don't care about the spelling of the identifier (besides purely mechanical concerns, like making sure it satisfies the RFC 3986 production rules).
URI are identifiers of resources. Resources are generalizations of documents. Therefore, human beings are likely to be happier if your identifier looks like the name of a document, rather than the name of an action.
Where it gets tricky: HTTP is an application protocol whose application domain is the transfer of files over a network. The methods in HTTP are about retrieving documents and metadata (GET/HEAD) or are about modifying documents (PATCH/POST/PUT). The notion of a function, or a parameterized query, doesn't really exist in HTTP.
The usual compromise is to make the parameters part of the identifier for a document, then use a GET request to fetch the current representation of that document. On the server, you parse the identifier to obtain the arguments you need to generate the current representation of the document.
So the identifier for this might look something like
/invoicedQuantityForPOItems?purchaseOrder=12345&productIdentifiers=567,890
An application/x-www-form-urlencoded representation of key value pairs embedded in the query part of the URI is a common spelling convention on the web, primarily because that's how HTML forms work with GET actions. Other identifier conventions can certainly work, though you'll probably be happier in the long term if you stick to a convention that is easily described by a URI template.

QueryString Structure of a Conditial Retrieve in OneM2M?

This is an example resource tree.
I need to retrieve latest 48 hours' data of cnt-2 and cnt-0 all together. What kind of query string should I put to the request ?
/in-cse
/in-cse/ae-123
/in-cse/cnt-2
/in-cse/cin-21
/in-cse/cin-22
/in-cse/cin-23
/in-cse/ae-124
/in-cse/cnt-0
/in-cse/cin-01
/in-cse/cin-02
/in-cse/cin-03
/in-cse/cnt-1
/in-cse/cin-11
/in-cse/cin-22
/in-cse/cin-33
Where should I put the ids of cnt-0 and cnt-2 in the querystring ?
/onem2m/api/v1/~/in-cse?fu=2&crb=20190808T000000&cra=20190806T000000&ty=4
Also should I use only querystring to make discovery or is it valid to make a POST request ?
With the example request in your question you will also get all the matching <contentInstance> resources of cnt-1, because you do the discovery on the level of the IN-CSE. Unfortunately, you cannot have multiple targets in a single request, but I see at least two solutions that could work for your use case:
You can add labels two <contentInstance> resources and add label to your search.
/onem2m/api/v1/~/in-cse?fu=2&crb=20190808T000000&cra=20190806T000000&label=myLabel&ty=4
You can add a <group> that contains the <container> resources that are important to your use case (ie. cnt-0 and cnt-2) and make the <group>'s fanoutPoint the target of your discovery request. The CSE is then responsible to redirect the discovery to each member of the <group>.
/onem2m/api/v1/~/in-cse/aGroup/fopt?fu=2&crb=20190808T000000&cra=20190806T000000&ty=4
In my opinion the second method is the more "elegant" one because it makes the (application) relationship of the two <container> resources clearer , but the first one might also be feasible if your <contentInstance> resources are tagged using labels anyway.
Regarding the POST request: For the HTTP binding query parameters are only allowed for filtering and discovery. Please have a look at TS-0009, section 6.2.2.2 Query component.
Btw, there are currently ongoing discussions in oneM2M to describe the differences between retrieval and discovery a bit better.

JSON API REST endpoint with permissions-restricted fields

JSON API REST endpoint with permissions-restricted fields
I am working on a JSON API-compliant REST api. Some endpoints contain fields that should be restricted (read-only or not available) for certain users.
What is the best way to architect the api to allow that certain users have access to certain fields, while others do not? By "best", I mean:
Most compliant with REST standards, ideally JSON API standards
Most clarity in terms of preventing bugs and confusion on behalf of clients consuming the API
I am considering the following options, each with their set of concerns/ questions. I would be more than grateful for any other solutions!
Option 1: Return null on restricted fields for users without permissions
Different data values would be returned per-user. Is this strictly anti-REST?
Lack of distinction between null meaning "null value" and null meaning "You don't have access to this"
In REST/ JSON API architecture, is it okay for an endpoint to return different data per user, based on permissions? I have the impression that this would be contrary to the spirit of resource-based REST architecture, but I could not find anything specific to point to in any doc or standard (e.g. JSON API). Also applies to Option 2.
Is there any paradigm for adding some sort of "You don't have access" flag in the resource's metadata?
Option 2: Exclude restricted fields entirely for users without permissions
Different data values would be returned per-user. Is this strictly anti-REST?
Possibility of "undefined" errors in client, when trying to retrieve field value
Option 3: Move restricted field(s) onto another endpoint, available as an ?include='field_name' relation for those with permission
Example: /api/entity includes attribute field "cost" which is only available to Admin users. Admin users can request cost data via GET /api/entity?include=cost. For all users, "cost" is exposed as a relation in the resource object, with a "type" and "id".
This is the option I am leaning toward. The main con here is endpoint clutter. I have a lot of relations that would need to be made into separate endpoints, simply to support a permissions-quarantined data on an already-existing endpoint.
In the JSON API specs, I am having trouble determining if it's ok for an endpoint to exist as a relation only, e.g. can we have /api/entity/1/cost, but NOT have a top-level api endpoint, /api/cost. My assumption is that if a resource has a "type" (in this case, the relation type being 'cost'), it also has to live on a top-level endpoint.
In this scenario, the client could get a 401: Unauthorized error response if a non-admin user tries to GET /api/entity?include=cost or GET /api/cost/:id
Note: I have already built a separate permissions schema so that the client can determine which CRUD privileges the user has, per top-level endpoint, before making any requests. Permission sets are indexed by resource type.
Any help on the matter would be very much appreciated! And if anything needs to be clarified, feel free to ask.
I would definitely not use undefined or null to indicate fields that the user is not allowed to see. To me, that feels like a lie and represents that the data is really not there. They would have to really know your API in order to get a grasp of what is really going on.
I would recommend something more like your 3rd option, except I would make it a different endpoint altogether. So in your example, the endpoints would be:
/api/entity/1/cost
and for admins
/api/admin/entity/1/cost
or something like that.
This way your server code for the admin endpoint could just be focused on authenticating this admin user and getting them back all the fields that they have visibility on. If a non admin user tries to hit that route, reject them with an unauthorized status code.
I'm not saying that you should not implement the GET param to be able to specify fields as well. You can if you want to, but I don't think it just won't be necessary in this case.

Combining GET and POST in Sinatra (Ruby)

I am trying to make a RESTful api and have some function which needs credentials. For example say I'm writing a function which finds all nearby places within a certain radius, but only authorised users can use it.
One way to do it is to send it all using GET like so:
http://myapi.heroku.com/getNearbyPlaces?lon=12.343523&lat=56.123533&radius=30&username=john&password=blabla123
but obviously that's the worst possible way to do it.
Is it possible to instead move the username and password fields and embed them as POST variables over SSL, so the URL will only look like so:
https://myapi.heroku.com/getNearbyPlaces?lon=12.343523&lat=56.123533&radius=30
and the credentials will be sent encrypted.
How would I then in Sinatra and Ruby properly get at the GET and POST variables? Is this The Right Way To Do It? If not why not?
If you are really trying to create a restful API instead if some URL endpoints which happen to speak some HTTP dialect, you should stick to GET. It's even again in your path, so you seem to be pretty sure it's a get.
Instead of trying to hide the username and password in GET or POST parameters, you should instead use Basic authentication, which was invented especially for that purpose and is universally available in clients (and is available using convenience methods in Sinatra).
Also, if you are trying to use REST, you should embrace the concept of resources and resoiurce collections (which is implied by the R and E of REST). So you have a single URL like http://myapi.heroku.com/NearbyPlaces. If you GET there, you gather information about that resource, if you POST, you create a new resource, if you PUT yopu update n existing resource and if you DELETE, well, you delete it. What you should do before is th structure your object space into these resources and design your API around it.
Possibly, you could have a resource collection at http://myapi.heroku.com/places. Each place as a resource has a unique URL like http://myapi.heroku.com/places/123. New polaces can be created by POSTing to http://myapi.heroku.com/places. And nearby places could be gathered by GETing http://myapi.heroku.com/places/nearby?lon=12.343523&lat=56.123533&radius=30. hat call could return an Array or URLs to nearby places, e.g.
[
"http://myapi.heroku.com/places/123",
"http://myapi.heroku.com/places/17",
"http://myapi.heroku.com/places/42"
]
If you want to be truly discoverable, you might also embrace HATEOAS which constraints REST smentics in a way to allows API clients to "browse" through the API as a user with a browser would do. To allow this, you use Hyperlink inside your API which point to other resources, kind of like in the example above.
The params that are part of the url (namely lon, lat and radius) are known as query parameters, the user and password information that you want to send in your form are known as form parameters. In Sinatra both of these type of parameters are made available in the params hash of a controller.
So in Sinatra you would be able to access your lon parameter as params[:lon] and the user parameter as params[:user].
I suggest using basic or digest authentication and a plain GET request. In other words, your request should be "GET /places?lat=x&lon=x&radius=x" and you should let HTTP handle the authentication. If I understand your situation correctly, this is the ideal approach and will certainly be the most RESTful solution.
As an aside, your URI could be improved. Having verbs ("get") and query-like adjectives ("nearby") in your resource names is not really appropriate. In general, resources should be nouns (ie. "places", "person", "books"). See the example request I wrote above; "get" is redundant because you are using a GET request and "nearby" is redundant because you are already querying by location.

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