I have a webapp written mostly in ruby compiled with opal. I now would like to store/retrieve file in my owncloud, maybe using WebDAV. I am looking for an example how to do this using HTTP module.
I tried
HTTP.get("https://owncloud/foo.abc") do |req|
req.username= "user"
...
end.then do |response|
puts response
end
But that does not work. no method then for module HTTP.
So it seem that if I pass a block to HTTP.get it no longer returns a promise.
When I do not pass a block I don' know
how to configure the request.
Best if I could find an full example how to use HTTP from opal.
The small example in opal blog die not hell out.
I think username/password should be passed in the options hash (see the opal-jquery README).
HTTP.get("https://owncloud/foo.abc", username: 'user').then do |response|
puts response
end
A note about the Promise-style:
The block is used as the default form of callback. To switch to promise-style you should not pass any block, instead try assigning the result of HTTP.get to a variable to modify the request options:
req = HTTP.get("https://owncloud/foo.abc")
puts req.inspect # <= do something with the request
req.then do |response|
puts response
end
Related
In the Ruby-doc Net/HTTP there is a detailed example for streaming response bodies - it applies when you try to download a large file.
I am looking for an equivalent code snippet to upload a file via PUT. Spent quite a bit of time trying to make code work with no luck. I think I need to implement a particular interface and pass it the to request.body_stream
I need streaming because I want to alter the content of the file while it is being uploaded so I want to have access to the buffered chunks while the upload takes place. I would gladly use a library like http.rb or rest-client as long as I can use streaming.
Thanks in advance!
For reference following is the working non streamed version
uri = URI("http://localhost:1234/upload")
Net::HTTP.start(uri.host, uri.port) do |http|
request = Net::HTTP::Put.new uri
File.open("/home/files/somefile") do |f|
request.body = f.read()
end
# Ideally I would need to use **request.body_stream** instead of **body** to get streaming
http.request request do |response|
response.read_body do |result|
# display the operation result
puts result
end
end
end
When I run the curl command
curl -v -H "Content-type: application/json" -X POST -d '{"name":"abc", "id":"12", "subject":"my subject"}' http://localhost:9292
to send a POST request with data to my Rack application, my code prints out {}. That is coming from puts req.POST() in the code below.
Why does it print out {} instead of the POST data? And how do I correctly access the POST data in my Rack application?
require 'json'
class Greeter
def call(env)
req = Rack::Request.new(env)
if req.post?
puts req.POST()
end
[200, {"Content-Type" => "application/json"}, [{x:"Hello World!"}.to_json]]
end
end
run Greeter.new
From reading the docs for POST, looks like it is giving you parsed data based on other content types. If you want to process "application/json", you probably need to
JSON.parse( req.body.read )
instead. To check this, try
puts req.body.read
where you currently have puts req.POST.
req.body is an I/O object, not a string. See the body documentation and view the source. You can see that this is in fact the same as mudasobwa's answer.
Note that other code in a Rack application may expect to read the same I/O, such as the param parsers in Sinatra or Rails. To ensure that they see the same data and not get an error, you may want to call req.body.rewind, possibly both before and after reading the request body in your code. However, if you are in such a situation, you might instead consider whether your framework has options to process JSON directly via some option on the controller or request content-type handler declaration etc - most likely there will be an option to handle this kind of request within the framework.
Try:
env['rack.input'].read
I found it in "How to receive a JSON object with Rack" and, though it still sounds weird to me, it likely works.
You can try:
req.params
Hope this can help you.
I'm migrating servers but unfortunately the old server IP is hardcoded inside my iPhone app. Obviously I'm going to submit an update that sets the API endpoint to my new server, but in the meantime I need to setup an app on the old server that redirects all the requests to the new server. I've heard Sinatra would be perfect for this.
require 'sinatra'
get "/foo/bar" do
redirect "http://new-server.com/foo/bar", 303
end
post "/foo/bar" do
redirect "http://new-server.com/foo/bar", 303
end
The problem is that these do not forward the GET or POST parameters along with the request. I read on the Sinatra doc that you can do that by putting them in the URL directly (works for GET requests), or by setting session variables.
Is manually parsing and formatting the GET params to put them back into the redirect URL the only way to go for GET redirects? How are you supposed to forward POST parameters?
For GET requests, use request.fullpath or request.query_string. For POST request, use status code 307, so the subsequent request will be a POST with the same parameters.
helpers do
def new_url
"http://new-server.com" + request.fullpath
end
end
get "/foo/bar" do
redirect new_url
end
post "/foo/bar" do
redirect new_url, 307
end
I would overload the Hash class in lib/overload_hash.rb, like so:
class Hash
def to_url_params
elements = []
keys.size.times do |i|
elements << "#{keys[i]}=#{values[i]}"
end
elements.join('&')
end
end
EDIT (Better solution using net / http)
Place a require "lib/overload_hash", require "net/http" and require "uri" under require 'sinatra'. The following example can be translated into GET easily.
post '/foo/bar' do
uri = URI.parse("http://example.com/search")
response = Net::HTTP.post_form(uri, params.to_ur_params)
response
end
I'm trying to use a super simple API from is.gd:
http://is.gd/api.php?longurl=http://www.example.com
Which returns a response header "HTTP/1.1 200 OK" if the URL was shortened as expected, or "HTTP/1.1 500 Internal Server Error" if there was any problem that prevented this. Assuming the request was successful, the body of the response will contain only the new shortened URL
I don't even know where to begin or if there are any available ruby methods to make sending and receiving of these API requests frictionless. I basically want to assign the response (the shortened url) to a ruby object.
How would you do this? Thanks in advance.
Super simple:
require 'open-uri'
def shorten(url)
open("http://is.gd/api.php?longurl=#{url}").read
rescue
nil
end
open-uri is part of the Ruby standard library and (among other things) makes it possible to do HTTP requests using the open method (which usually opens files). open returns an IO, and calling read on the IO returns the body. open-uri will throw an exception if the server returns a 500 error, and in this case I'm catching the exception and return nil, but if you want you can let the exception bubble up to the caller, or raise another exception.
Oh, and you would use it like this:
url = "http://www.example.com"
puts "The short version of #{url} is #{shorten(url)}"
I know you already got an answer you accepted, but I still want to mention httparty because I've made very good experiences wrapping APIs (Delicious and Github) with it.
It seems like the methods of Ruby's Net::HTTP are all or nothing when it comes to reading the body of a web page. How can I read, say, the just the first 100 bytes of the body?
I am trying to read from a content server that returns a short error message in the body of the response if the file requested isn't available. I need to read enough of the body to determine whether the file is there. The files are huge, so I don't want to get the whole body just to check if the file is available.
This is an old thread, but the question of how to read only a portion of a file via HTTP in Ruby is still a mostly unanswered one according to my research. Here's a solution I came up with by monkey-patching Net::HTTP a bit:
require 'net/http'
# provide access to the actual socket
class Net::HTTPResponse
attr_reader :socket
end
uri = URI("http://www.example.com/path/to/file")
begin
Net::HTTP.start(uri.host, uri.port) do |http|
request = Net::HTTP::Get.new(uri.request_uri)
# calling request with a block prevents body from being read
http.request(request) do |response|
# do whatever limited reading you want to do with the socket
x = response.socket.read(100);
# be sure to call finish before exiting the block
http.finish
end
end
rescue IOError
# ignore
end
The rescue catches the IOError that's thrown when you call HTTP.finish prematurely.
FYI, the socket within the HTTPResponse object isn't a true IO object (it's an internal class called BufferedIO), but it's pretty easy to monkey-patch that, too, to mimic the IO methods you need. For example, another library I was using (exifr) needed the readchar method, which was easy to add:
class Net::BufferedIO
def readchar
read(1)[0].ord
end
end
Shouldn't you just use an HTTP HEAD request (Ruby Net::HTTP::Head method) to see if the resource is there, and only proceed if you get a 2xx or 3xx response? This presumes your server is configured to return a 4xx error code if the document is not available. I would argue this was the correct solution.
An alternative is to request the HTTP head and look at the content-length header value in the result: if your server is correctly configured, you should easily be able to tell the difference in length between a short message and a long document. Another alternative: set the content-range header field in the request (which again assumes that the server is behaving correctly WRT the HTTP spec).
I don't think that solving the problem in the client after you've sent the GET request is the way to go: by that time, the network has done the heavy lifting, and you won't really save any wasted resources.
Reference: http header definitions
I wanted to do this once, and the only thing that I could think of is monkey patching the Net::HTTP#read_body and Net::HTTP#read_body_0 methods to accept a length parameter, and then in the former just pass the length parameter to the read_body_0 method, where you can read only as much as length bytes.
To read the body of an HTTP request in chunks, you'll need to use Net::HTTPResponse#read_body like this:
http.request_get('/large_resource') do |response|
response.read_body do |segment|
print segment
end
end
Are you sure the content server only returns a short error page?
Doesn't it also set the HTTPResponse to something appropriate like 404. In which case you can trap the HTTPClientError derived exception (most likely HTTPNotFound) which is raised when accessing Net::HTTP.value().
If you get an error then your file wasn't there if you get 200 the file is starting to download and you can close the connection.
You can't. But why do you need to? Surely if the page just says that the file isn't available then it won't be a huge page (i.e. by definition, the file won't be there)?