WOPI client and host query - ms-wopi

Trying to implement Collabora (CODE) editor on a web app. Currently writing the wopi host code, and I am seeking clarity on one minor detail:
Does wopi client (in my case, CODE) access the file directly from my wopi host using the url passed to it and then send the data to user's browser (in case of which, during updating, the data is posted to wopi client which in turn will post to wopi host? right?), or does accessing and updating the file is done from the user's browser through wopi host url?

This image of a WOPI-Conversation may help. The WOPI server (which is the server where the endpoints are), communicates with the WOPI client. The WOPI client then renders the iframe in the user browser. When saving, the WOPI client will POST the new content to the "PutFile" endpoint on the WOPI server to save it.

Related

Is it possible to specify a default WOPI host for Office Online Server?

Is there a way to specify a default WOPI host for Office Online Server (local installation, not cloud), so that the domain part in WOPISrc param can be omitted?
I am building a host page that uses an iframe to display the Online Office editor, and it bugs me that WOPI host information is exposed as the WOPISrc param of the iframe source URL.
No, there is no way to do that. From this perspective, OOS works in a kinda stateless fashion.
And even if there was a way, the URL couldn't be truly protected...obscured perhaps, but not protected.

How can I avoid hardcoding URLs in a RESTful client/server web app with deep linking?

I'm working on a SPA which is a client to a RESTful web service. Both the client and server are part of the same project, i.e. I can modify the code for both sides freely. I've been reading up on RESTful API design to try and make sure I'm doing everything the "right" way. One of my takeaways from reading is that a RESTful service should publish hyperlinks so clients can access more information, and that clients should have no hardcoded information about service URLs other than an entry point. Using hyperlinks allows the client to be more flexible in the event that the server makes URL changes.
However I can't figure out how this architecture is supposed to work when users are allowed to link to a specific client state. For example:
One of the views is a list of books available for purchase. The client sets the browser's location to /books/ to identify this page, and the backend data comes from an endpoint /api/books/, retrieved from an API entry point that publishes that URL. The service URL responds with a JSON document like this:
[
{"title": "The Great Gatsby",
"id": 24,
"url": "http://localhost/api/books/24/"},
< and so on >
]
The client uses this to generate readable links that, when clicked, go to a detailed view of a single book. The browser's location is updated to /books/the-great-gatsby/24/ so users can bookmark this view and link to it.
How does the client handle when users click this link directly?? How would it know where to get the information for this book without having a hardcoded URL?
The best I could come up with is the following sequence of requests:
GET /api/ - view which services are available (to find there are books at all)
OPTIONS /api/books/ - view a description of what operations are available on books (so e.g. it can make sure it can find books by ID)
GET /api/books/?id=24 - See if it can find a book with an ID that matches the ID in the browser's location.
GET /api/books/24/ - Actually retrieve the data
Anything shorter would imply that the client has hardcoded knowledge of the API's URLs. However, from a web app point of view, this seems grossly inefficient.
Is there some trick I'm missing? Is there a way for the client to "know" how to get more detail about book ID 24 without somehow having the /api/books/24/ endpoint hardcoded?
if you request this resource /books/the-great-gatsby/24/ from the server, the server should respond with something specific to that URL. Currently, you are probably analyzing window.location which is a bit of a hack.
If /books/the-great-gatsby/24/ is static content, then you have very little choice: You store the client's current state explicitly somewhere (i.e. /books?data=api/books/24 or implicitly /books/the-great-gatsby/24/ which then leads to the client having to know how to translate that to an API resource.
The RESTful way is to use hypertext to indicate where any related resources (i.e. your data to render is) are which makes a tag an appropriate choice.
i.e. ditch the static content, and render /books/the-great-gatsby/24/ with a <head><link href="api/books/24" ....></link></head>
However, if you always retain control of your client side and don't plan to publish the API to third parties, you might be more productive ditching RESTful and just go RESTish.
The Resource URL Locator pattern
In this answer: user is (the human interacting with) the internet browser, client is the Single Page Application (SPA) and server is the REST API.
Deep linking is a convenience of the client to the user; the client itself may still not have knowledge of the server's URLs, so the client must start at the root URL of the server. The client uses content negotiation to indicate which media type it needs. The first request of the client to the server when bootstrapping itself could be as follows:
GET /?id=24 HTTP/1.1
Accept: application/vnd.company.book+json
Optionally, the client uses the id querystring parameter as a hint to the server to select the specific resource it is looking for.
When the server has determined which resource the client is looking for it can respond with a redirect to the canonical URL of the resource:
HTTP/1.1 303 See Other
Location: https://example.com/api/books/24
The client can now follow the redirect and get the resource it needs to bootstrap the application.
#Evert's comment got me thinking. Isn't a deep link or a bookmark just a continuation of application state from a previous point in time? It doesn't really matter how much time has passed after the previous application state transition.
You could say that the 'current' application state in HATEOAS is the last followed link. The current state must be stored somewhere and it might as well be stored in the application URL.
Starting the application at a deep link indicates to the application that it should rebuild the application state by requesting the resource indicated by the application URL. If the resource is no longer available or has moved, the server should respond with a 404 Not Found or 301 Moved Permanently respectively.
With this approach the server is still in control of the URLs. The application follows the hypermedia links in the server's responses and doesn't generate URLs itself.

What's the REST way to verify an email?

When a user register to my web application I send an email to verify his inbox.
In the email there are a link to a resource like this:
GET /verify/{token}
Since the resource is being updated behind the scenes, doesn't it break the RESTful approach?
How can I do it in a RESTful manner?
What you are talking about is not REST. REST is for machine to machine communication and not for human to machine communication. You can develop a 1st party REST client, which sends the activation to the REST service.
You can use your verification URI in the browser to access the REST client:
# user follows a hyperlink in the browser manually
GET example.com/client/v1/verify/{token}
# asking the client to verify the token
and after that the REST client will get the hyperlink for verification from the REST service and send the POST to the service in the background.
# the REST client follows the hyperlinks given by the service automatically
# the REST client can run either on the HTTP client or server side
GET example.com/api/v1
# getting the starting page of the REST service
# getting the hyperlink for verification
POST example.com/api/v1/verification {token}
# following the verification hyperlink
If you have a server side 1st party REST client, then the HTTP requests to the REST service will run completely on the server and you won't see anything about it in the browser. If you have a client side REST client, then you can send the POST in the browser with AJAX CORS or you can try to POST directly with a HTML form (not recommended). Anyways the activation should be a POST or a PUT.
It depends on what are you trying to do.
Does it fire an email after validating the user for example? If so, it is not an idempotent method and you should use POST.
Example:
POST /users/{id}/verify/{token}
If the method doesn't have any consequence besides the update, I think you should use PUT.
Aren't you overthinking REST? With e-mail verification you want the user to be able to simply click the link from whatever mail user agent he is using, so you'll end up with a simple GET on the server (presented as a hyperlink to the user) with the token either in the path or as part of the query string:
GET http://example.com/verify-email/TOKEN
GET http://example.com/verify-email?token=TOKEN
Either is fine for this use case. It is not really a resource you are getting or creating; just a trigger for some process on the backend.
Why do you think this would run afoul of good design?

Can a Facebook app fetch data from an external server using HTTP requests

Want to access data from external service for a facebook application. Not getting a solution on how to do the same.
Facebook apps are iframes inside Facebook. If your application has it's own server-side code, you can access that external service from the server and send the results to the client.
If you don't have your own server-side code, relying on Facebook objects for persistence, than you can access the remote service from the client via JavaScript - but there is a "but". Browsers usually only allow JavaScript to send requests to the domain where the page came from, and obviously your app is not served from the domain of the external service(otherwise it wouldn't be "external"). That means your users will have to set the security options in their browsers to allow access to remote domains - which means you'll have to supply instructions on how to do that, and we all know how good users are at following instructions... Also, having to change security options might scare away some users.
So - if possible, try to do it from your server-side.

Sending all webpage requests from uiwebview through a proxy server

I have an app and a server that I am working with. The server acts as a proxy server. In my app, I have a uiwebview which sends a request to the proxy server. The proxy server then generates a response for the uiwebview, sending back the requested page, but the problem is that the uiwebview does not load any of the the resource urls in the page such as style sheets, images etc. through the proxy server.
My question is, is there a way to send a response from the proxy server back to the uiwebview, telling the uiwebview to load all the resources through the proxy server, or is there a way to change all resource url requests made by a uiwebview to point to the proxy?
Have a read up about NSURLProtocol and see if that will meet your requirements to change the url requests to the proxy.