My quick Request class for CoffeeScript

request.coffee

# This is my first full blow coffeescript class Im working on
# thoughts?

class Request
    constructor: ->
        @xhrObjects = [
                -> new XMLHttpRequest()
                -> new ActiveXObject("Msxml2.XMLHTTP")
                -> new ActiveXObject("Microsoft.XMLHTTP")
            ]
            
        @request = null
        throw new Error("XMLHttpRequest not supported") if @request?

        for request in @xhrObjects
            do(request) =>
                try
                    requestObject = request()
                    @request = requestObject
                catch err
                    continue

    response: ->
        header  = @request.getResponseHeader("Content-Type")
        text    = @request.responseText
        
        if "javascript" in header
            eval(text)
        else if "json" in header
            JSON.parse(text)
            
        return text
        
    parseHeaders: ->
        headerObject = {}
        headers      = @request.getAllResponseHeaders()
        leadSpace    = /^\s*/
        trailSpace   = /\s*$/
        lines        = headers.split("\n")
        
        for line in lines
            if line.length == 0
                continue
            
            pos     = line.indexOf(':')
            name    = line.substring(0, post).replace(leadSpace, "").replace(trailSpace, "")
            value   = line.substring((post + 1)).replace(leadSpace, "").replace(trailSpace, "")
            
            headerObject[name] = value
            
        return headerObject
        
    queryString: (params)->
        query = new Array
        
        for key, value of params
            query.push("%@=%@".$$(key, value))
            
        return query.join("&") 
        
    encodeData: (data)->
        params = {}
        for item in data
            params[encodeURIComponent(item).replace(/%20/g, "+")] = encodeURIComponent(data[item].toString()).replace(/%20/g, "+")
            
        return @queryString(params)
        
    execute: (method, options)->
        throw new Error("No HTTP request method provided") unless method

        options ?= {}
        throw new Error("No URL was provided") unless options.url
        
        callback        = options.callback if options.callback?() else ->
        errorCallback   = options.error if options.error?() else (status, reason)-> 
                throw new Error("Error Status: %@ // Reason: %@".$$(status, reason))
        url             = options.url
        params          = option.params ? null
        async           = options.async ? true
        
        @request.onreadystatechange = =>
            if @request.readyState is 4
                if @request.status in [0, 200]
                    callback.apply(@, [@response()])
                else
                    errorCallback.apply(@, [@request.status, @request.statusText])


        params      = "?" + @queryString(params) if params
        requestUrl  = url + params if method is "GET" else url
        @request.open(method, requestUrl, async)
        
        if method is "POST"
            @request.setRequestHeader("Content-Type", "application/x-www-form-urlencode")
            @request.send(@encodeData(params))
        else
            @request.send(null)
            
        if not async
            return @response()
        
        
    get: (options)->
        @execute("GET", options)
        
    post: (options)->
        @execute("POST", options)