Golang Context.Has方法代码示例

// Flush sends content to output.
//
// If no writer is specified, this will attempt to write to whatever is in the
// Context with the key "http.ResponseWriter". If no suitable writer is found, it will
// not write to anything at all.
//
// Params:
// 	- writer: A Writer of some sort. This will try to write to the HTTP response if no writer
// 	is specified.
// 	- content: The content to write as a body. If this is a byte[], it is sent unchanged. Otherwise.
// 	we first try to convert to a string, then pass it into a writer.
// 	- contentType: The content type header (e.g. text/html). Default is text/plain
// 	- responseCode: Integer HTTP Response Code: Default is `http.StatusOK`.
// 	- headers: a map[string]string of HTTP headers. The keys will be run through
// 	 http.CannonicalHeaderKey()
//
// Note that this is optimized for writing from strings or arrays, not Readers. For larger
// objects, you may find it more efficient to use a different command.
//
// Context:
// - If this finds `web.ContentEncoding`, it will set a content-encoding header.
//
// Returns
//
// 	- boolean true
func Flush(cxt cookoo.Context, params *cookoo.Params) (interface{}, cookoo.Interrupt) {

	// Make sure we have a place to write this stuff.
	writer, ok := params.Has("writer")
	if writer == nil {
		writer, ok = cxt.Has("http.ResponseWriter")
		if !ok {
			return false, nil
		}
	}
	out := writer.(http.ResponseWriter)

	// Get the rest of the info.
	code := params.Get("responseCode", http.StatusOK).(int)
	header := out.Header()
	contentType := params.Get("contentType", "text/plain; charset=utf-8").(string)

	// Prepare the content.
	var content []byte
	rawContent, ok := params.Has("content")
	if !ok {
		// No content. Send nothing in the body.
		content = []byte("")
	} else if byteContent, ok := rawContent.([]byte); ok {
		// Got a byte[]; add it as is.
		content = byteContent
	} else {
		// Use the formatter to convert to a string, and then
		// cast it to bytes.
		content = []byte(fmt.Sprintf("%v", rawContent))
	}

	// Add headers:
	header.Set(http.CanonicalHeaderKey("content-type"), contentType)

	te := cxt.Get(ContentEncoding, "").(string)
	if len(te) > 0 {
		header.Set(http.CanonicalHeaderKey("transfer-encoding"), te)
	}

	headerO, ok := params.Has("headers")
	if ok {
		headers := headerO.(map[string]string)
		for k, v := range headers {
			header.Add(http.CanonicalHeaderKey(k), v)
		}
	}

	// Send the headers.
	out.WriteHeader(code)

	//io.WriteString(out, content)
	out.Write(content)

	return true, nil
}

// ServeFiles is a cookoo command to serve files from a set of filesystem directories.
//
// If no writer is specified, this will attempt to write to whatever is in the
// Context with the key "http.ResponseWriter". If no suitable writer is found, it will
// not write to anything at all.
//
// Example:
//
//     registry.Route("GET /**", "Serve assets").
//         Does(web.ServeFiles, "fileServer").
//            Using("directory").WithDefault("static")
//
// Example 2:
//
//     registry.Route("GET /foo/**", "Serve assets").
//         Does(web.ServeFiles, "fileServer").
//             Using("directory").WithDefault("static").
//             Using("removePrefix").WithDefault("/foo")
//
// Params:
// 	- directory: A directory to serve files from.
// 	- removePrefix: A prefix to remove from the url before looking for it on the filesystem.
// 	- writer: A Writer of some sort. This will try to write to the HTTP response if no writer
// 	  is specified.
// 	- request: A request of some sort. This will try to use the HTTP request if no request
// 	  is specified.
func ServeFiles(cxt cookoo.Context, params *cookoo.Params) (interface{}, cookoo.Interrupt) {

	writer, ok := params.Has("writer")
	if writer == nil {
		writer, ok = cxt.Has("http.ResponseWriter")
		if !ok {
			return nil, &cookoo.Reroute{"@404"}
		}
	}
	out := writer.(http.ResponseWriter)

	req, ok := params.Has("request")
	if req == nil {
		req, ok = cxt.Has("http.Request")
		if !ok {
			return nil, &cookoo.Reroute{"@404"}
		}
	}

	in := req.(*http.Request)

	directory := params.Get("directory", nil)
	if directory == nil {
		return nil, &cookoo.Reroute{"@404"}
	}

	prefix := params.Get("removePrefix", "").(string)
	urlPath := strings.TrimPrefix(in.URL.Path, prefix)
	staticFile := path.Join(directory.(string), urlPath)

	info, err := os.Stat(staticFile)
	if err != nil {
		return nil, &cookoo.Reroute{"@404"}
	}

	if info.IsDir() == false {
		http.ServeFile(out, in, staticFile)
		return true, nil
	}
	return nil, &cookoo.Reroute{"@404"}
}

func (r *RequestResolver) Resolve(path string, cxt cookoo.Context) (string, error) {
	// Parse out any flags. Maybe flag specs are in context?

	flagsetO, ok := cxt.Has("globalFlags")
	if !ok {
		// No args to parse. Just return path.
		return path, nil
	}
	flagset := flagsetO.(*flag.FlagSet)
	flagset.Parse(strings.Split(path, " "))
	addFlagsToContext(flagset, cxt)
	args := flagset.Args()

	// This is a failure condition... Need to fix Cookoo to support error return.
	if len(args) == 0 {
		return path, &cookoo.RouteError{"Could not resolve route " + path}
	}

	// Put the rest of the args to the context.
	cxt.Put("args", args[1:])

	// Parse argv[0] as subcommand
	return args[0], nil
}