sourceafBedSheet::HttpRequestHeaders.fan

** A wrapper for HTTP request headers with accessors for some commonly used headings.
** 
** @see `https://en.wikipedia.org/wiki/List_of_HTTP_header_fields`
class HttpRequestHeaders {
    
    private Str:Str headers

    internal new make(Str:Str headers) { this.headers = headers }

    ** List of acceptable encodings.
    ** 
    ** Example: 'Accept-Encoding: compress;q=0.5, gzip;q=1.0'
    QualityValues acceptEncoding {
        get { QualityValues(headers["Accept-Encoding"]) }
        private set { }
    }

    Str? accessControlRequestHeaders {
        get { headers["Access-Control-Request-Headers"] }
        private set { }
    }

    Str? accessControlRequestMethod {
        get { headers["Access-Control-Request-Method"]?.upper }
        private set { }
    }

    ** The MIME type of the body of the request (used with POST and PUT requests)
    ** 
    ** Example: 'Content-Type: application/x-www-form-urlencoded'
    MimeType? contentType {
        get { makeIfNotNull("Content-Type") { MimeType(it, true) }}
        private set { }
    }

    ** The domain name of the server (for virtual hosting), and the TCP port number on which the 
    ** server is listening. The port number may be omitted if the port is the standard port for 
    ** the service requested.
    ** 
    ** Example: 'Host: www.alienfactory.co.uk:8069'
    Uri? host {
        get { headers["Host"]?.toUri }
        private set { }
    }

    ** Allows a 304 Not Modified to be returned if content is unchanged.
    ** 
    ** Example: 'If-Modified-Since: Sat, 29 Oct 1994 19:43:31 GMT'
    DateTime? ifModifiedSince {
        get { makeIfNotNull("If-Modified-Since") { DateTime.fromHttpStr(it, true) }}
        private set { }
    }

    ** Allows a 304 Not Modified to be returned if content is unchanged.
    ** 
    ** Example: 'If-None-Match: "737060cd8c284d8af7ad3082f209582d"'
    Str? ifNoneMatch {
        get { headers["If-None-Match"] }
        private set { }
    }

    ** Initiates a request for cross-origin resource sharing.
    ** 
    ** Example: 'Origin: http://www.example-social-network.com'
    Str? origin {
        get { headers["Origin"] }
        private set { }
    }

    ** This is the address of the previous web page from which a link to the currently requested 
    ** page was followed. 
    ** 
    ** Example: 'Referer: http://en.wikipedia.org/wiki/Main_Page'
    Uri? referrer {
        // yeah, I know I've mispelt referrer!
        // see `https://en.wikipedia.org/wiki/HTTP_referrer`
        get { headers["Referer"]?.toUri }
        private set { }
    }

    ** The user agent string of the user agent.
    ** 
    ** Example: 'User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20100101 Firefox/21.0'
    Str? userAgent {
        get { headers["User-Agent"] }
        private set { }
    }

    ** Mainly used to identify Ajax requests. 
    ** 
    ** Example: 'X-Requested-With: XMLHttpRequest'
    Str? xRequestedWith {
        get { headers["X-Requested-With"] }
        private set { }
    }



    @Operator
    Str? get(Str name) {
        headers[name]
    }

    Void each(|Str val, Str key| c) {
        headers.each(c)
    }
    
    Str:Str map() {
        headers
    }
    
    private Obj? makeIfNotNull(Str name, |Obj->Obj| func) {
        val := headers[name]
        return (val == null) ? null : func(val)
    }

}