Currently provides an HTTP Client based on libcurl

All HTTP request APIs take in a object of type RequestOptions

type RequestOptions
    blocking::Bool 
    query_params::Vector{Tuple} 
    request_timeout::Float64
    callback::Union(Function,Bool)
    content_type::String
    headers::Vector{Tuple}
    ostream::Union{IO, Nothing}
    auto_content_type::Bool
end

• By default all APIs block till request completion and return Response objects.

• If blocking is set to false, then the API returns immediately with a RemoteRef.

• The user can pass in a complete url in the url parameter of the API, or can set query_params as a Vector of (Name, Value) tuples

  In the former case, the passed url is executed as is.

  In the latter case the complete URL if formed by concatenating the url field, a "?" and the escaped (name,value) pairs. Both the name and values must be convertible to appropriate ASCIIStrings.

• In file upload cases, an attempt is made to set the content_type type automatically as derived from the file extension unless auto_content_type is set to false.

• auto_content_type - default is true. If the content_type has not been explicitly specified, the library will try to guess the content type for a PUT/POST from the file extension. For POST it will default to "application/x-www-form-urlencoded". Set this parameter to false to override this behaviour

• Default value for the request_timeout is 0.0 seconds, i.e., never timeout.

• If a callback is specified, its signature should be customize_cb(curl) where curl is the libCURL handle. The callback can further customize the request by using libCURL easy* APIs directly

• headers - additional headers to be set. Vector of {Name, Value} Tuples

• ostream - if set as an IO, any returned data to written to ostream. If it is a String, it is treated as a filename and written to the file. In both these cases the data is not returned as part of the Response object

Each API returns an object of type

    type Response
        body::IOBuffer
        headers::Dict{ASCIIString, ASCIIString}
        http_code::Int
        total_time::Float64
    end

If you expecting ascii text as a response, for example, html content, or json, bytestring(r.body) will return the stringified response. For binary data use the functions described in http://docs.julialang.org/en/latest/stdlib/base/#i-o to access the raw data.

The exported APIs from module HTTPClient are :

 get(url::String, options::RequestOptions)

 post (url::String, data, options::RequestOptions)

 put (url::String, data, options::RequestOptions)

• For both post and put above, the data can be either a
  • String - sent as is.
  • IOStream - Content type is set to "application/octet-stream" unless specified otherwise
  • Dict{Name, Value} or Vector{Tuple{Name, Value}} - Content type is set to "application/x-www-form-urlencoded" unless specified otherwise
  • (:file, filename::String) - The file is read, and the content-type is set automatically unless specified otherwise.

 head(url::String, options::RequestOptions)
 
 delete(url::String, options::RequestOptions)
 
 trace(url::String, options::RequestOptions)
 
 options(url::String, options::RequestOptions)

The options can also be specified as named arguments in each of the above APIS. For example, get(url; blocking=false, request_timeout=30.0)

The names are field names of RequestOptions

• See test/tests.jl for sample code

• Change the sleep in a loop to using fdwatcher when support for fdwatcher becomes available in mainline