How to view TCL REST Response headers - rest

My code sample was
package require rest
set yweather(forecast) {
url http://weather.yahooapis.com/forecastrss
req_args { p: }
opt_args { u: }
}
rest::create_interface yweather
Output
% set res [yweather::forecast -p 94089]
channel {title {content {Yahoo! Weather - Sunnyvale, CA}} .........
But i am trying to view Response header, like Status codes, set-cookie information. I don't know how to view, some one please help to resolve this issue.
Thanks

Typically with handling REST, I'd just use the standard http package directly (or wrapped into a little class). That would let you use http::meta to get at the gory response details, and also let you control much more precisely what message gets sent in the first place (usually rather important!)
However, that's me (as I'm pretty au fait with REST and the http package). Let's dig into the rest package more carefully and get it to do what we want.
By close reading of the documentation, I see that the interface descriptor dictionary allows the keys pre_transform and post_transform, and that the http token is available in the calling context. Let's try with the post_transform…
package require rest
set yweather(forecast) {
url http://weather.yahooapis.com/forecastrss
req_args { p: }
opt_args { u: }
post_transform extract_metadata
}
rest::create_interface yweather
proc extract_metadata {response} {
upvar 1 token token
lappend response [http::meta $token]
return $response
}
Now, if you do:
set res [yweather::forecast -p 94089]
You should get the extra information you want (and far more probably!) in the meta field at the end.

Related

convenience method in spray (soon to be akka-http) to create a Location header w/ host port & contextRoot ?

When I create an object through POST in my Spray app I'd like to return a 201 status, together with a Location header that has the absolute URI of the newly created resource (including host port & contextRoot of my app)
Here is an example code fragment from my application...
post {
respondWithHeaders(Location( fullyQualifiedUri("/movies"))) {
entity(as[MovieImpl]) { (movieToInsert: MovieImpl) => {
addMovies(movieToInsert)
complete("OK")
}
}
}
}
Note that I now have to write the method 'fullyQualifiedUri' to return
a URI with host, port, etc. It would be nice if Spray did that for me
automagically.
Side note:
I think that having the Location header include the absolute URI of the newly
created resource makes it easier on my REST API's clients (although it does seem that there are a variety of opinions on this.)
Thanks in advance for any guidance you can provide.
-chris
To build the URI you'll need the Id of the newly created resource. Then you can use the requestInstance directive to get the incoming request URI and build the new resource URI from it. You also need to set the return code to Created to meet your requirements:
post {
requestInstance { request =>
val movieId = ???
respondWithHeaders(Location( request.uri.withPath(request.uri.path / movieId))) {
entity(as[MovieImpl]) { (movieToInsert: MovieImpl) => {
addMovies(movieToInsert)
complete(StatusCodes.Created)
}
}
}
}
}

PUT Request not happening at all in Fantom

I am having some trouble with PUT requests to the google sheets api.
I have this code
spreadsheet_inputer := WebClient(`$google_sheet_URI_cells/R3C6?access_token=$accesstoken`)
xml_test := XDoc{
XElem("entry")
{
addAttr("xmlns","http://www.w3.org/2005/Atom")
addAttr("xmlns:gs","http://schemas.google.com/spreadsheets/2006")
XElem("id") { XText("https://spreadsheets.google.com/feeds/cells/$spreadsheet_id/1/private/full/R3C6?access_token=$accesstoken"), },
XElem("link") { addAttr("rel","edit");addAttr("type","application/atom+xml");addAttr("href","https://spreadsheets.google.com/feeds/cells/$spreadsheet_id/1/private/full/R3C6?access_token=$accesstoken"); },
XElem("gs:cell") { addAttr("row","3");addAttr("col","6");addAttr("inputValue","testing 123"); },
},
}
spreadsheet_inputer.reqHeaders["If-match"] = "*"
spreadsheet_inputer.reqHeaders["Content-Type"] = "application/atom+xml"
spreadsheet_inputer.reqMethod = "PUT"
spreadsheet_inputer.writeReq
spreadsheet_inputer.reqOut.writeXml(xml_test.writeToStr).close
echo(spreadsheet_inputer.resStr)
Right now it returns
sys::IOErr: No input stream for response 0
at the echo statement.
I have all the necessary data (at least i'm pretty sure) and it works here https://developers.google.com/oauthplayground/
Just to note, it does not accurately update the calendars.
EDIT: I had it return the response code and it was a 0, any pointers on what this means from the google sheets api? Or the fantom webclient?
WebClient.resCode is a non-nullable Int so it is 0 by default hence the problem would be either the request not being sent or the response not being read.
As you are obviously writing the request, the problem should the latter. Try calling WebClient.readRes() before resStr.
This readRes()
Read the response status line and response headers. This method may be called after the request has been written via writeReq and reqOut. Once this method completes the response status and headers are available. If there is a response body, it is available for reading via resIn. Throw IOErr if there is a network or protocol error. Return this.
Try this:
echo(spreadsheet_inputer.readRes.resStr)
I suspect the following line will also cause you problems:
spreadsheet_inputer.reqOut.writeXml(xml_test.writeToStr).close
becasue writeXml() escapes the string to be XML safe, whereas you'll want to just print the string. Try this:
spreadsheet_inputer.reqOut.writeChars(xml_test.writeToStr).close

Spray Authentication method with BasicAuth

Spray is hard!! I now know that my knowledge on HTTP protocol is not nearly enough and API design isn't easy. However, I still very much want my practice app to work. I'm writing this authentication for POST/PUT/DELETE method. It appears that there are at least two ways to do this: BasicAuth or write a custom directive.
I found this article:
BasicAuth: https://github.com/jacobus/s4/blob/master/src/main/scala/s4/rest/S4Service.scala
I'm trying it out because it looks simple.
The compile and run stages are fine, and the server runs. However, when I'm trying to send a PUT request to test the implementation (using Python's Httpie: http PUT 127.0.0.1:8080/sec-company/casper username=username token=123), the feedback is:HTTP/1.1 404 Not Found
Here's my route:
pathPrefix("sec-company") {
path("casper") {
//first examine username and token
authenticate(BasicAuth(CustomUserPassAuthenticator, "company-security")) {userProfile =>
post { ctx =>
entity(as[Company.Company]) { company =>
complete {
company
}
}
}
}
Here is my implementation of UserPassAuthenticator:
object CustomUserPassAuthenticator extends UserPassAuthenticator[UserProfile] {
def apply(userPass: Option[UserPass]) = Promise.successful(
userPass match {
case Some(UserPass(user, token)) => getUserProfile(user, token)
case _ => None
}
).future
}
First of all, is this the right way to implement authentication? Second, where does UserPassAuthenticator find the username and password?? Can I send back a better HTTP header other than 404 to indicate failed authentication?
If this is far from correct, is there any tutorial on authentication that I can follow? TypeSafe's Spray templates are more about overall patterns and less about Spray's functionality!
Thank you!
I had the same problem, even after looking at https://github.com/spray/spray/wiki/Authentication-Authorization (which says it's for an older version of Akka but it still seems to apply) I came up with the following:
trait Authenticator {
def basicUserAuthenticator(implicit ec: ExecutionContext): AuthMagnet[AuthInfo] = {
def validateUser(userPass: Option[UserPass]): Option[AuthInfo] = {
for {
p <- userPass
user <- Repository.apiUsers(p.user)
if user.passwordMatches(p.pass)
} yield AuthInfo(user)
}
def authenticator(userPass: Option[UserPass]): Future[Option[AuthInfo]] = Future { validateUser(userPass) }
BasicAuth(authenticator _, realm = "Private API")
}
}
I mix in this trait into the Actor that runs the routes and then I call it like this:
runRoute(
pathPrefix("api") {
authenticate(basicUserAuthenticator) { authInfo =>
path("private") {
get {
authorize(authInfo.hasPermission("get") {
// ... and so on and so forth
}
}
}
}
}
}
The AuthInfo object returned by the validateUser method is passed as a parameter to the closure given to the authorize method. Here it is:
case class AuthInfo(user: ApiUser) {
def hasPermission(permission: String) = user.hasPermission(permission)
}
In Spray (and HTTP), authentication (determining whether you have a valid user) is separate from authorization (determining whether the user has access to a resource). In the ApiUser class I also store the set of permissions the user has. This is a simplified version, my hasPermission method is a bit more complex since I also parametrize permissions, so it's not just that a particular user has permission to do a get on a resource, he might have permission to read only some parts of that resource. You might make things very simple (any logged-in user can access any resource) or extremely complex, depending on your needs.
As to your question, when using HTTP BASIC authentication (the BasicAuth object), the credentials are passed in the request in an Authorization: header. Your HTTP library should take care of generating that for you. According to the HTTP standard, the server should return a 401 status code if the authentication was incorrect or not provided, or a 403 status code if the authentication was correct but the user doesn't have permissions to view the content.

Getting a 204 No Content response when I use restSetResponse in Coldfusion 10 REST

I am trying to use restSetResponse to set my own status and content as described in the docs here:
http://help.adobe.com/en_US/ColdFusion/10.0/Developing/WSe61e35da8d318518-5719eac51353e6bb244-7fec.html
Here is my REST method:
remote any function test() httpmethod="get" {
var response = {
status: 400,
content: 'something is wrong'
};
restSetResponse(response);
}
Any help would be greatly appreciated. Thanks!
In the link you provided, note the first numbered bullet under the "Send custom success responses using restSetResponse" heading. If you define the CFC as REST service, you need to ensure the returnType is set to "void". In your example, you have your returnType set to "any".

What's the best way to handle a REST API's 'create' response in Backbone.js

I'm using backbone.js to interact with a REST API that, when posting to it to create a new resource, responds with a status of 201, a 'Location' header pointing to the resource's URI, but an empty body.
When I create a new model at the moment, its successful, but the local representation of the model only contains the properties I explicitly set, not any of the properties that would be set on the server (created_date, etc.)
From what I understand, Backbone would update its representation of the model with data in the body, if there were any. But, since there isn't, it doesn't.
So, clearly, I need to use the location in the Location header to update the model, but what's the best way to do this.
My current mindset is that I would have to parse the url from the header, split out the id, set the id for the model, then tell the model to fetch().
This seems really messy. Is there a cleaner way to do it?
I have some influence over the API. Is the best solution to try to get the API author to return the new model as the body of the response (keeping the 201 and the location header as well)?
Thanks!
Sounds like you will have to do a little customization.
Perhaps override the parse method and url method of your model class inherited from
Backbone.Model.
The inherited functions are:
url : function() {
var base = getUrl(this.collection);
if (this.isNew()) return base;
return base + (base.charAt(base.length - 1) == '/' ? '' : '/') + this.id;
},
parse : function(resp) {
return resp;
},
and you could try something like:
parse: function(resp, xhr) {
this._url = xhr.getResponseHeader('location')
return resp
}
url: function() {
return this._url
}
Yes, backbone.js really wants the result of a save (be it PUT or POST) to be a parseable body which can be used to update the model. If, as you say, you have influence over the API, you should see if you can arrange for the content body to contain the resource attributes.
As you point out, its makes little sense to make a second over-the-wire call to fully materialize the model.
It may be that a status code of 200 is more appropriate. Purists may believe that a 201 status code implies only a location is returned and not the entity. Clearly, that doesn't make sense in this case.
With Backbone 0.9.9, I couldn't get the accepted answer to work. The signature of the parse function seems to have changed in an older version, and the xhr object is no longer available in the function signature.
This is an example of what I did, to make it work with Backbone v0.9.9 and jQuery 1.8.3 (using a Deferred Object/Promise), relying on the jqXHR object returned by Backbone.Model.save() :
window.CompanyView = Backbone.View.extend({
// ... omitted other functions...
// Invoked on a form submit
createCompany: function(event) {
event.preventDefault();
// Store a reference to the model for use in the promise
var model = this.model;
// Backbone.Model.save returns a jqXHR object
var xhr = model.save();
xhr.done(function(resp, status, xhr) {
if (!model.get("id") && status == "success" && xhr.status == 201) {
var location = xhr.getResponseHeader("location");
if (location) {
// The REST API sends back a Location header of format http://foo/rest/companys/id
// Split and obtain the last fragment
var fragments = location.split("/");
var id = fragments[fragments.length - 1];
// Set the id attribute of the Backbone model. This also updates the id property
model.set("id", id);
app.navigate('companys/' + model.id, {trigger: true});
}
}
});
}
});
I did not use the success callback that could be specified in the options hash provided to the Backbone.Model.save function, since that callback is invoked before the XHR response is received. That is, it is pointless to store a reference to the jqXHR object and use it in the success callback, since the jqXHR would not contain any response headers (yet) when the callback is invoked.
Another other to solve this would be to write a custom Backbone.sync implementation, but I didn't prefer this approach.