3 ms·

To be fair, you need at least one hard-coded URL in your client, don't you? To hit the root entrypoint. And if you have one hard-coded URL... and use it as the

by slver 5y ago

To be fair, you need at least one hard-coded URL in your client, don't you? To hit the root entrypoint. And if you have one hard-coded URL... and use it as the root of other URLs, then it's no hard to support than anything. URLs are useful in REST because the API often crosses domain boundaries and company boundaries. One site links to another and so on. Most APIs are not like that. In fact they're only like that when they serve, say, static image assets off a CDN, and guess what, then passing back a URL in your API is self-evident and natural. But not for everything IMHO.

unscaled 5y ago
If you look at the hydra API example[1] linked by OP, this is exactly what it needs: one entrypoint URL. If your API only needs a single domain name (as over 99% of the APIs are), clients can just have the base URL encoded in a constant or a configuration file. What HATEOAS ostensibly gives you is not the ability to painlessly switch domains, but rather to change your entire URL path structure and even the entire schema represented by your REST endpoints. This feature turns out to be quite useless for most REST clients. Cosmetic changes to URL structure aside, any useful change (in other words - a schema change), will break the client logic, which is still hard-coded to deal with a predefined schema, predefined types of resources and a predefined set of actions that can be performed on each of them. Roy Fielding accurately notes that a truly "RESTful" app should let the engine of its state be completely driven by the server. In other words the client cannot have any _specific_ logic related to "state transfers". If your client is not doing this, like a browser does, than what does it have left to gain from implementing HATEOAS? I'm honestly interested in hearing good arguments, since I haven't heard anything that managed to convince me yet. I've always worked all my API up to level 2 (HTTP Verbs) of the Richardson Maturity model, but I've never felt convinced that HATEOAS is worth the effort. It seems like the majority of HTTP API designers out there have the same opinion. [1]: https://generic.hypermedia.app/ https://generic.hypermedia.app/
- slver 5y ago
  > What HATEOAS ostensibly gives you is not the ability to painlessly switch domains, but rather to change your entire URL path structure and even the entire schema represented by your REST endpoints. Which would be utterly pointless, because the fact this schema is opaque to the clients means that it's meaningless to the clients. So you have no reason to change it. > I've always worked all my API up to level 2 (HTTP Verbs) of the Richardson Maturity model, but I've never felt convinced that HATEOAS is worth the effort. It seems like the majority of HTTP API designers out there have the same opinion. The "maturity model" is honestly non-sense and Fielding also thinks that. It's kinda like first level to being a bird is flapping your hands, second step is whistling with your mouth... No, you're not any closer to being a bird, you need to be the entire thing for the benefits of being a bird to come about. Trying to stick to the CRUD concept of HTTP verbs is rather harmful. CRUD is a common starting point for a domain's verb structure, but being restricted to it is crippling and results in bizarre obscure semantics or underdeveloped business constraints. I'd say to hell with all of it. I stick to HTTP as-is, and that's it. Also it's telling I think that to this day HTML forms only support GET and POST. Even HTML isn't RESTful I guess. /s
  - unscaled 5y ago
    While Level 3, as currently implemented by some APIs, is a cargo-culted version of Fielding's idea of HATEOAS, Level 1 and 2 of the model have some usefulness for some types of APIs. What you get by implementing what is called a "RESTful API" nowadays is something that is very different from the original concept of REST, but is still useful to some applications, over plain RPC. Let's unpack it. Fielding RESTful system as a system which implement the following constraints: 1. Follows a Client-Server model 2. Is Stateless (request-response model) 3. Indicates cacheability of responses 4. Has Uniform Interface defined by the following restrictions: Identification of resources (URIs); Manipulation of resources through representations (media types); Self-descriptive messages; Hypermedia as the engine of application state (HATEOAS) 5. Isolates access to non-adjacent layers 6. (Optional) Supports code on demand. Applying all the restrictions stated above, lets you immense benefits: for instance cacheability, stateless and uniform resource identification make your system easy to distribute and scale to handle large amount of traffic; self-describing messages, manipulation of resources through representations and code-on-demand let you have a system that can evolve gracefully without requiring a big bang protocol upgrade. The half-assed "RESTful APIs" of today implement only a subset of the constraints listed above. They are always client-serves, stateless, isolate access to non-adjacent layers and implement two of the uniform interface restrictions (URIs and manipulation of resources through representations). Sometimes they also indicate cacheability. However, they do not support HATEOAS (including most of the level 3 wannabes), code-on-demand and most importantly self-describing messages. The lack of the constraints above means our modern APIs cannot achieve some of the benefits the web browser does: most notably flexibility and open-ended evolution. But they do have some other benefits over traditional RPC systems. I think the maturity model itself is quite useless, but the following properties are useful: 1. Correct HTTP verbs: Differentiating between PUT and POST will let your intermediaries know when the request can be retried. 2. URIs uniquely identify resources: beyond the obvious benefit (cachability), it allows for easy sharding, distribution and smart redirection by any intermediary server. With traditional HTTP-RPC (even with a standardized protocol like gRPC or SOAP), your intermediary has to be fully aware of the RPC schema to cache or know when it can retry. If you want to add a sharding gateway you need to especially develop a customized solution. A Level 2 "RESTful API" still has all these benefits.

by slver 5y ago

unscaled 5y ago

If you look at the hydra API example[1] linked by OP, this is exactly what it needs: one entrypoint URL. If your API only needs a single domain name (as over 99% of the APIs are), clients can just have the base URL encoded in a constant or a configuration file. What HATEOAS ostensibly gives you is not the ability to painlessly switch domains, but rather to change your entire URL path structure and even the entire schema represented by your REST endpoints. This feature turns out to be quite useless for most REST clients. Cosmetic changes to URL structure aside, any useful change (in other words - a schema change), will break the client logic, which is still hard-coded to deal with a predefined schema, predefined types of resources and a predefined set of actions that can be performed on each of them. Roy Fielding accurately notes that a truly "RESTful" app should let the engine of its state be completely driven by the server. In other words the client cannot have any _specific_ logic related to "state transfers". If your client is not doing this, like a browser does, than what does it have left to gain from implementing HATEOAS? I'm honestly interested in hearing good arguments, since I haven't heard anything that managed to convince me yet. I've always worked all my API up to level 2 (HTTP Verbs) of the Richardson Maturity model, but I've never felt convinced that HATEOAS is worth the effort. It seems like the majority of HTTP API designers out there have the same opinion. [1]: https://generic.hypermedia.app/ https://generic.hypermedia.app/

slver 5y ago
> What HATEOAS ostensibly gives you is not the ability to painlessly switch domains, but rather to change your entire URL path structure and even the entire schema represented by your REST endpoints. Which would be utterly pointless, because the fact this schema is opaque to the clients means that it's meaningless to the clients. So you have no reason to change it. > I've always worked all my API up to level 2 (HTTP Verbs) of the Richardson Maturity model, but I've never felt convinced that HATEOAS is worth the effort. It seems like the majority of HTTP API designers out there have the same opinion. The "maturity model" is honestly non-sense and Fielding also thinks that. It's kinda like first level to being a bird is flapping your hands, second step is whistling with your mouth... No, you're not any closer to being a bird, you need to be the entire thing for the benefits of being a bird to come about. Trying to stick to the CRUD concept of HTTP verbs is rather harmful. CRUD is a common starting point for a domain's verb structure, but being restricted to it is crippling and results in bizarre obscure semantics or underdeveloped business constraints. I'd say to hell with all of it. I stick to HTTP as-is, and that's it. Also it's telling I think that to this day HTML forms only support GET and POST. Even HTML isn't RESTful I guess. /s
- unscaled 5y ago
  While Level 3, as currently implemented by some APIs, is a cargo-culted version of Fielding's idea of HATEOAS, Level 1 and 2 of the model have some usefulness for some types of APIs. What you get by implementing what is called a "RESTful API" nowadays is something that is very different from the original concept of REST, but is still useful to some applications, over plain RPC. Let's unpack it. Fielding RESTful system as a system which implement the following constraints: 1. Follows a Client-Server model 2. Is Stateless (request-response model) 3. Indicates cacheability of responses 4. Has Uniform Interface defined by the following restrictions: Identification of resources (URIs); Manipulation of resources through representations (media types); Self-descriptive messages; Hypermedia as the engine of application state (HATEOAS) 5. Isolates access to non-adjacent layers 6. (Optional) Supports code on demand. Applying all the restrictions stated above, lets you immense benefits: for instance cacheability, stateless and uniform resource identification make your system easy to distribute and scale to handle large amount of traffic; self-describing messages, manipulation of resources through representations and code-on-demand let you have a system that can evolve gracefully without requiring a big bang protocol upgrade. The half-assed "RESTful APIs" of today implement only a subset of the constraints listed above. They are always client-serves, stateless, isolate access to non-adjacent layers and implement two of the uniform interface restrictions (URIs and manipulation of resources through representations). Sometimes they also indicate cacheability. However, they do not support HATEOAS (including most of the level 3 wannabes), code-on-demand and most importantly self-describing messages. The lack of the constraints above means our modern APIs cannot achieve some of the benefits the web browser does: most notably flexibility and open-ended evolution. But they do have some other benefits over traditional RPC systems. I think the maturity model itself is quite useless, but the following properties are useful: 1. Correct HTTP verbs: Differentiating between PUT and POST will let your intermediaries know when the request can be retried. 2. URIs uniquely identify resources: beyond the obvious benefit (cachability), it allows for easy sharding, distribution and smart redirection by any intermediary server. With traditional HTTP-RPC (even with a standardized protocol like gRPC or SOAP), your intermediary has to be fully aware of the RPC schema to cache or know when it can retry. If you want to add a sharding gateway you need to especially develop a customized solution. A Level 2 "RESTful API" still has all these benefits.