The ResponseCacheAttribute supports VaryByQueryKeys, which obviously creates a cache miss if the query string (or specified parts of the query string differ).
But, REST API design guidelines prefer the key of an HTTP GET to be in the route.
e.g.:
http://example.com/api/books/123
http://example.com/api/books/987
Whereas if you want to cache book 123 or 987 and vary the cache it would need to be?:
e.g.
http://example.com/api/books?id=123
http://example.com/api/books?id=987
I feel like I am missing something. There is no "VaryByRoute" property of "ResponseCacheAttribute".
There are mentions of "vary-by-route" in classic ASPNET (not core) I noticed headers of vary-by-route being used, but those are not directly appliable in ASP.NET core.
How should this be handled?
How do I vary the caching by the route where one of the parts of the route path is the "key"?
This post is a bit old and I hope you already had your answer, but this question appears in searches so I'll write a short one.
Whereas if you want to cache book 123 or 987 and vary the cache it would need to be?:
No. Both paths goes to the same action method, where all query parameters (whether they are explicit or not) are paired with the ones on the method that are named.
So, assuming you have an action that can be simplified like this:
public IActionResult Get(int id)
the ResponseCache attribute will works even if you omit the key name in the url path.
I'm trying to create a chat bot that will help users search up motorcycles.
I'm new to API.AI and have set up my entities and their synonyms, my intent and user expressions, as well as references to the entities (#engineSize, #make, #bikeType).
My problem is when I try to add a required action and prompt, and then try to save the intent, I get the following message:
"The following entities reference each other and form an infinite loop: [engineSize]."
Initially I thought I was using the references wrong in the user expressions. I deleted every reference except for one expression which uses all three entities.
I can't figure out what I'm doing wrong. Any help would be greatly appreciated, thanks! Pix below for further details.
EDIT: I fixed one of the issues of trying to pass a template expression as an example. However, I still get the same error message. I will replace and update my image links to include the edits.
Annotated User expressions
Required Actions
Interestingly enough, the answer to this post would have been difficult to find because the problem was in defining my entities.
In the entity definitions, I included an #ref to the entity itself. ie the bikeType entity contained #bikeType as one of its definitions.
This is not to be mistaken with the User Expressions. As long as the user expression is marked as a Template (the entire line is denoted with an '#' on the far left, as opposed to a large " ), there should be no issues.
Edited for clarity to get at root problem
In the provided user input examples you give the intent, you are supposed to provide general examples and then highlight any text belonging to an entity to map where entities appear in user's inquiries.
In your case, you have input the actual entity reference '#engineSize' as an example belonging to the engineSize entity, creating a self reference.
A proper provided user example would look like:
Also note though that if you are just using entities to store generic information like numbers, addresses, times, etc. it generally makes far more sense to use prebuilt system entities for those categories than create a custom entity, for example #sys.number-integer might be exactly what you need
It looks like you need to get a firmer understanding of entities, for which I would recommend the documentation:
https://docs.api.ai/docs/concept-entities
I'm wondering whether it is at all possible to make the client ask the server for a given string, and incorporate it into another string ?
I don't see how to do that using the async approach.
As far as I know there is no really simple way to do this, because the i18n machanism of GWT replaces strings at compile-time and not at runtime.
You can try one of the following approaches:
Load the i18n in your entrypoint, store all messages in a local Map and create the Label etc, with the values from you cache. PRO: all GWT standard CONS: one request more, before you can show a translated page
Use JSP and no HTML at serverside. Wthin you jsp can create a JSON from your
message.properties and put it into your hostpage. PRO: You can synchronous read te values CONS: You will need to write a JSP which reads the properties for the correnct language, You will need to write a JSNI method to load the translated values.
Rethink, if you need a different way of translation. The built-in i18n will create tranlated versions of your app at compile-tim
I think I would use the second approach.
I have extended the UserBase class in System.ServiceModel.DomainServices.Server.ApplicationServices in my Silverlight RIA, and yes people still use Silverlight, and I was wondering what the best practice would be regarding IsInRole(#"domain\groupName") and how I might get away from using a hard-coded group name?
I am using Windows auth and an Authentication DomainService.
You could put all your domain\group strings in a static class - then at least your hardcoded strings are all in one place.
If you wish to use the RequiresRole attribute then the strings will need to be const rather than static otherwise VS will complain during build.
Hardcoded group name isn't so bad - the problem is a hardcoded domain name IMHO - since you can define groups that are exclusive to your application and push the onus on setup onto the network admin (this is how many Windows server applications behave)
Alternatively you could use standard ASP.NET roles and have some custom mapping between domain groups and ASP.NET roles (a bit like how SQL Server must do it)
What is the best way to version REST URIs? Currently we have a version # in the URI itself, ie.
http://example.com/users/v4/1234/
for version 4 of this representation.
Does the version belong in the queryString? ie.
http://example.com/users/1234?version=4
Or is versioning best accomplished another way?
Do not version URLs, because ...
you break permalinks
The url changes will spread like a disease through your interface. What do you do with representations that have not changed but point to the representation that has? If you change the url, you break old clients. If you leave the url, your new clients may not work.
Versioning media types is a much more flexible solution.
Assuming that your resource is returning some variant of application/vnd.yourcompany.user+xml all you need to do is create support for a new application/vnd.yourcompany.userV2+xml media type and through the magic of content negotiation your v1 and v2 clients can co-exist peacefully.
In a RESTful interface, the closest thing you have to a contract is the definition of the media-types that are exchanged between the client and the server.
The URLs that the client uses to interact with the server should be provided by the server embedded in previously retrieved representations. The only URL that needs to be known by the client is the root URL of the interface. Adding version numbers to urls only has value if you construct urls on the client, which you are not suppose to do with a RESTful interface.
If you need to make a change to your media-types that will break your existing clients then create a new one and leave your urls alone!
And for those readers currently saying that this makes no sense if I am using application/xml and application/json as media-types. How are we supposed to version those? You're not. Those media-types are pretty much useless to a RESTful interface unless you parse them using code-download, at which point versioning is a moot point.
I would say making it part of the URI itself (option 1) is best because v4 identifies a different resource than v3. Query parameters like in your second option can be best used to pass-in additional (query) info related to the request, rather than the resource.
Ah, I'm putting my old grumpy hat on again.
From a ReST perspective, it doesn't matter at all. Not a sausage.
The client receives a URI it wants to follow, and treats it as an opaque string. Put whatever you want in it, the client has no knowledge of such a thing as a version identifier on it.
What the client knows is that it can process the media type, and I'll advise to follow Darrel's advice. Also I personally feel that needing to change the format used in a restful architecture 4 times should bring huge massive warning signs that you're doing something seriously wrong, and completely bypassing the need to design your media type for change resiliance.
But either way, the client can only process a document with a format it can understand, and follow links in it. It should know about the link relationships (the transitions). So what's in the URI is completely irrelevant.
I personally would vote for http://localhost/3f3405d5-5984-4683-bf26-aca186d21c04
A perfectly valid identifier that will prevent any further client developer or person touching the system to question if one should put v4 at the beginning or at the end of a URI (and I suggest that, from the server perspective, you shouldn't have 4 versions, but 4 media types).
You should NOT put the version in the URL, you should put the version in the Accept Header of the request - see my post on this thread:
Best practices for API versioning?
If you start sticking versions in the URL you end up with silly URLs like this:
http://company.com/api/v3.0/customer/123/v2.0/orders/4321/
And there are a bunch of other problems that creep in as well - see my blog:
http://thereisnorightway.blogspot.com/2011/02/versioning-and-types-in-resthttp-api.html
These (less-specific) SO questions about REST API versioning may be helpful:
Versioning RESTful services?
Best practices for web service REST API versioning
There are 4 different approaches to versioning the API:
Adding version to the URI path:
http://example.com/api/v1/foo
http://example.com/api/v2/foo
When you have breaking change, you must increment the version like: v1, v2, v3...
You can implement a controller in you code like this:
#RestController
public class FooVersioningController {
#GetMapping("v1/foo")
public FooV1 fooV1() {
return new FooV1("firstname lastname");
}
#GetMapping("v2/foo")
public FooV2 fooV2() {
return new FooV2(new Name("firstname", "lastname"));
}
Request parameter versioning:
http://example.com/api/v2/foo/param?version=1
http://example.com/api/v2/foo/param?version=2
The version parameter can be optional or required depending on how you want the API to be used.
The implementation can be similar to this:
#GetMapping(value = "/foo/param", params = "version=1")
public FooV1 paramV1() {
return new FooV1("firstname lastname");
}
#GetMapping(value = "/foo/param", params = "version=2")
public FooV2 paramV2() {
return new FooV2(new Name("firstname", "lastname"));
}
Passing a custom header:
http://localhost:8080/foo/produces
With header:
headers[Accept=application/vnd.company.app-v1+json]
or:
headers[Accept=application/vnd.company.app-v2+json]
Largest advantage of this scheme is mostly semantics: You aren’t cluttering the URI with anything to do with the versioning.
Possible implementation:
#GetMapping(value = "/foo/produces", produces = "application/vnd.company.app-v1+json")
public FooV1 producesV1() {
return new FooV1("firstname lastname");
}
#GetMapping(value = "/foo/produces", produces = "application/vnd.company.app-v2+json")
public FooV2 producesV2() {
return new FooV2(new Name("firstname", "lastname"));
}
Changing Hostnames or using API Gateways:
Essentially, you’re moving the API from one hostname to another. You might even just call this building a new API to the same resources.
Also,you can do this using API Gateways.
I wanted to create versioned APIs and I found this article very useful:
http://blog.steveklabnik.com/posts/2011-07-03-nobody-understands-rest-or-http
There is a small section on "I want my API to be versioned". I found it simple and easy to understand. The crux is to use Accept field in the header to pass version information.
If the REST services require authentication before use, you could easily associate the API key/token with an API version and do the routing internally. To use a new version of the API, a new API key could be required, linked to that version.
Unfortunately, this solution only works for auth-based APIs. However, it does keep versions out of the URIs.
If you use URIs for versioning, then the version number should be in the URI of the API root, so every resource identifier can include it.
Technically a REST API does not break by URL changes (the result of the uniform interface constraint). It breaks only when the related semantics (for example an API specific RDF vocab) changes in a non backward compatible way (rare). Currently a lot of ppl do not use links for navigation (HATEOAS constraint) and vocabs to annotate their REST responses (self-descriptive message constraint) that's why their clients break.
Custom MIME types and MIME type versioning does not help, because putting the related metadata and the structure of the representation into a short string does not work. Ofc. the metadata and the structure will frequently change, and so the version number too...
So to answer your question the best way to annotate your requests and responses with vocabs (Hydra, linked data) and forget versioning or use it only by non backward compatible vocab changes (for example if you want to replace a vocab with another one).
I'd include the version as an optional value at the end of the URI. This could be a suffix like /V4 or a query parameter like you've described. You might even redirect the /V4 to the query parameter so you support both variations.
I vote up for doing this in mime type but not in URL.
But the reason is not the same as other guys.
I think the URL should be unique (excepting those redirects) for locating the unique resource.
So, if you accept /v2.0 in URLs, why it is not /ver2.0 or /v2/ or /v2.0.0? Or even -alpha and -beta? (then it totally becomes the concept of semver)
So, the version in mime type is more acceptable than the URL.