Fix http://support.iris-go.com/d/17-fallback-handler-for-non-matched-routes/9

Former-commit-id: 8a8a25ab8fb33a342c8d05fc7eae7cafd5bb02b2

HISTORY.md

@@ -8,8 +8,18 @@
 
 
 ## 6.1.4 -> 6.2.0 (√Νεxτ)
+_Update: 12 March 2017_
 
-_Last update: 28 Feb 2017_
+- Enhance Custom http errors with gzip and static files handler, as requested/reported [here](http://support.iris-go.com/d/17-fallback-handler-for-non-matched-routes/9).
+- Enhance per-party custom http errors (now it works on any wildcard path too).
+- Add a third parameter on `app.OnError(...)` for custom http errors with regexp validation, see [status_test.go](https://github.com/kataras/iris/blob/v6/status_test.go) for an example.
+- Add a `context.ParamIntWildcard(...)` to skip the first slash, useful for wildcarded paths' parameters.
+
+
+> Prepare for nice things, tomorrow is Iris' first birthday!
+
+
+_Update: 28 Feb 2017_
 
 > Note: I want you to know that I spent more than 200 hours (16 days of ~10-15 hours per-day, do the math) for this release, two days to write these changes, please read the sections before think that you have an issue and post a new question, thanks!
 

context.go

@@ -164,8 +164,12 @@ var _ ContextPool = &contextPool{}
 
 func (c *contextPool) Acquire(w http.ResponseWriter, r *http.Request) *Context {
 	ctx := c.pool.Get().(*Context)
+	ctx.Middleware = nil
+	ctx.session = nil
 	ctx.ResponseWriter = acquireResponseWriter(w)
 	ctx.Request = r
+	ctx.values = ctx.values[0:0]
+
 	return ctx
 }
 
@@ -173,13 +177,8 @@ func (c *contextPool) Release(ctx *Context) {
 	// flush the body (on recorder) or just the status code (on basic response writer)
 	// when all finished
 	ctx.ResponseWriter.flushResponse()
-
-	ctx.Middleware = nil
-	ctx.session = nil
-	ctx.Request = nil
 	///TODO:
 	ctx.ResponseWriter.releaseMe()
-	ctx.values.Reset()
 
 	c.pool.Put(ctx)
 }
@@ -810,8 +809,8 @@ func (ctx *Context) WriteGzip(b []byte) (int, error) {
 		ctx.ResponseWriter.Header().Add(varyHeader, acceptEncodingHeader)
 
 		gzipWriter := acquireGzipWriter(ctx.ResponseWriter)
+		defer releaseGzipWriter(gzipWriter)
 		n, err := gzipWriter.Write(b)
-		releaseGzipWriter(gzipWriter)
 
 		if err == nil {
 			ctx.SetHeader(contentEncodingHeader, "gzip")
@@ -1307,6 +1306,28 @@ func (ctx *Context) ParamInt(key string) (int, error) {
 	return ctx.GetInt(key)
 }
 
+// ParamIntWildcard removes the first slash if found and
+// returns the int representation of the key's wildcard path parameter's value.
+//
+// Returns -1 with an error if the parameter couldn't be found.
+func (ctx *Context) ParamIntWildcard(key string) (int, error) {
+	v := ctx.Get(key)
+	if v != nil {
+		if vint, ok := v.(int); ok {
+			return vint, nil
+		} else if vstring, sok := v.(string); sok {
+			if len(vstring) > 1 {
+				if vstring[0] == '/' {
+					vstring = vstring[1:]
+				}
+			}
+			return strconv.Atoi(vstring)
+		}
+	}
+
+	return -1, errIntParse.Format(v)
+}
+
 // ParamInt64 returns the int64 representation of the key's path named parameter's value
 func (ctx *Context) ParamInt64(key string) (int64, error) {
 	return strconv.ParseInt(ctx.Param(key), 10, 64)

fs.go

@@ -1,12 +1,23 @@
 package iris
 
 import (
+	"fmt"
+	"io"
 	"mime"
+	"mime/multipart"
 	"net/http"
+	"net/textproto"
+	"net/url"
 	"os"
+	"path"
 	"path/filepath"
+	"sort"
+	"strconv"
 	"strings"
 	"sync"
+	"time"
+
+	"github.com/kataras/go-errors"
 )
 
 // StaticHandlerBuilder is the web file system's Handler builder
@@ -149,26 +160,55 @@ func (w *fsHandler) Build() HandlerFunc {
 	w.once.Do(func() {
 		w.filesystem = w.directory
 
-		// set the filesystem to itself in order to be recognised of listing property (can be change at runtime too)
-		fileserver := http.FileServer(w)
-		fsHandler := fileserver
-		if w.stripPath {
-			prefix := w.requestPath
-			fsHandler = http.StripPrefix(prefix, fileserver)
-		}
-
-		h := func(ctx *Context) {
-			writer := ctx.ResponseWriter
-
-			if w.gzip && ctx.clientAllowsGzip() {
-				ctx.ResponseWriter.Header().Add(varyHeader, acceptEncodingHeader)
-				ctx.SetHeader(contentEncodingHeader, "gzip")
-				gzipResWriter := acquireGzipResponseWriter(ctx.ResponseWriter) //.ResponseWriter)
-				writer = gzipResWriter
-				defer releaseGzipResponseWriter(gzipResWriter)
+		hStatic := func(ctx *Context) {
+			upath := ctx.Request.URL.Path
+			if !strings.HasPrefix(upath, "/") {
+				upath = "/" + upath
+				ctx.Request.URL.Path = upath
 			}
 
-			fsHandler.ServeHTTP(writer, ctx.Request)
+			// Note the request.url.path is changed but request.RequestURI is not
+			// so on custom errors we use the requesturi instead.
+			// this can be changed
+			_, prevStatusCode := serveFile(ctx,
+				w.filesystem,
+				path.Clean(upath),
+				false,
+				w.listDirectories,
+				(w.gzip && ctx.clientAllowsGzip()),
+			)
+
+			// check for any http errors after the file handler executed
+			if prevStatusCode >= 400 { // error found (404 or 400 or 500 usually)
+				if writer, ok := ctx.ResponseWriter.(*gzipResponseWriter); ok && writer != nil {
+					writer.ResetBody()
+					writer.Disable()
+					// ctx.ResponseWriter.Header().Del(contentType) // application/x-gzip sometimes lawl
+					// remove gzip headers
+					headers := ctx.ResponseWriter.Header()
+					headers[contentType] = nil
+					headers["X-Content-Type-Options"] = nil
+					headers[varyHeader] = nil
+					headers[contentEncodingHeader] = nil
+					headers[contentLength] = nil
+				}
+				// execute any custom error handler (per-party or global, if not found then it creates a new one and fires it)
+				ctx.Framework().Router.Errors.Fire(prevStatusCode, ctx)
+				return
+			}
+
+			// go to the next middleware
+			if ctx.Pos < len(ctx.Middleware)-1 {
+				ctx.Next()
+			}
+		}
+
+		var fileserver HandlerFunc
+
+		if w.stripPath {
+			fileserver = StripPrefix(w.requestPath, hStatic)
+		} else {
+			fileserver = hStatic
 		}
 
 		if len(w.exceptions) > 0 {
@@ -176,15 +216,17 @@ func (w *fsHandler) Build() HandlerFunc {
 			for i := range w.exceptions {
 				middleware[i] = Prioritize(w.exceptions[i])
 			}
-			middleware[len(w.exceptions)] = HandlerFunc(h)
+			middleware[len(w.exceptions)] = HandlerFunc(fileserver)
 
 			w.handler = func(ctx *Context) {
 				ctx.Middleware = append(middleware, ctx.Middleware...)
 				ctx.Do()
 			}
-		} else {
-			w.handler = h
+			return
 		}
+
+		w.handler = fileserver
+
 	})
 
 	return w.handler
@@ -209,6 +251,683 @@ func StripPrefix(prefix string, h HandlerFunc) HandlerFunc {
 	}
 }
 
+//  +------------------------------------------------------------+
+//  |                                                            |
+//  |                      serve file handler                    |
+//  | edited from net/http/fs.go in order to support GZIP with   |
+//  | custom iris http errors and fallback to non-compressed data|
+//  | when not supported.                                        |
+//  |                                                            |
+//  +------------------------------------------------------------+
+
+var htmlReplacer = strings.NewReplacer(
+	"&", "&amp;",
+	"<", "&lt;",
+	">", "&gt;",
+	// "&#34;" is shorter than "&quot;".
+	`"`, "&#34;",
+	// "&#39;" is shorter than "&apos;" and apos was not in HTML until HTML5.
+	"'", "&#39;",
+)
+
+func dirList(ctx *Context, f http.File) (string, int) {
+	dirs, err := f.Readdir(-1)
+	if err != nil {
+		// TODO: log err.Error() to the Server.ErrorLog, once it's possible
+		// for a handler to get at its Server via the http.ResponseWriter. See
+		// Issue 12438.
+		return "Error reading directory", StatusInternalServerError
+
+	}
+	sort.Slice(dirs, func(i, j int) bool { return dirs[i].Name() < dirs[j].Name() })
+
+	ctx.ResponseWriter.Header().Set(contentType, contentHTML+"; charset="+ctx.Framework().Config.Charset)
+	fmt.Fprintf(ctx.ResponseWriter, "<pre>\n")
+	for _, d := range dirs {
+		name := d.Name()
+		if d.IsDir() {
+			name += "/"
+		}
+		// name may contain '?' or '#', which must be escaped to remain
+		// part of the URL path, and not indicate the start of a query
+		// string or fragment.
+		url := url.URL{Path: name}
+		fmt.Fprintf(ctx.ResponseWriter, "<a href=\"%s\">%s</a>\n", url.String(), htmlReplacer.Replace(name))
+	}
+	fmt.Fprintf(ctx.ResponseWriter, "</pre>\n")
+	return "", StatusOK
+}
+
+// errSeeker is returned by ServeContent's sizeFunc when the content
+// doesn't seek properly. The underlying Seeker's error text isn't
+// included in the sizeFunc reply so it's not sent over HTTP to end
+// users.
+var errSeeker = errors.New("seeker can't seek")
+
+// errNoOverlap is returned by serveContent's parseRange if first-byte-pos of
+// all of the byte-range-spec values is greater than the content size.
+var errNoOverlap = errors.New("invalid range: failed to overlap")
+
+// The algorithm uses at most sniffLen bytes to make its decision.
+const sniffLen = 512
+
+// if name is empty, filename is unknown. (used for mime type, before sniffing)
+// if modtime.IsZero(), modtime is unknown.
+// content must be seeked to the beginning of the file.
+// The sizeFunc is called at most once. Its error, if any, is sent in the HTTP response.
+func serveContent(ctx *Context, name string, modtime time.Time, sizeFunc func() (int64, error), content io.ReadSeeker, gzip bool) (string, int) /* we could use the TransactionErrResult but prefer not to create new objects for each of the errors on static file handlers*/ {
+
+	setLastModified(ctx, modtime)
+	done, rangeReq := checkPreconditions(ctx, modtime)
+	if done {
+		return "", StatusNotModified
+	}
+
+	code := StatusOK
+
+	// If Content-Type isn't set, use the file's extension to find it, but
+	// if the Content-Type is unset explicitly, do not sniff the type.
+	ctypes, haveType := ctx.ResponseWriter.Header()[contentType]
+	var ctype string
+	if !haveType {
+		ctype = typeByExtension(filepath.Ext(name))
+		if ctype == "" {
+			// read a chunk to decide between utf-8 text and binary
+			var buf [sniffLen]byte
+			n, _ := io.ReadFull(content, buf[:])
+			ctype = http.DetectContentType(buf[:n])
+			_, err := content.Seek(0, io.SeekStart) // rewind to output whole file
+			if err != nil {
+				return "seeker can't seek", StatusInternalServerError
+
+			}
+		}
+		ctx.ResponseWriter.Header().Set(contentType, ctype)
+	} else if len(ctypes) > 0 {
+		ctype = ctypes[0]
+	}
+
+	size, err := sizeFunc()
+	if err != nil {
+		return err.Error(), StatusInternalServerError
+	}
+
+	// handle Content-Range header.
+	sendSize := size
+	var sendContent io.Reader = content
+
+	if gzip {
+		// set the "Accept-Encoding" here in order to prevent the content-length header to be setted later on.
+		ctx.SetHeader(contentEncodingHeader, "gzip")
+		ctx.ResponseWriter.Header().Add(varyHeader, acceptEncodingHeader)
+		gzipResWriter := acquireGzipResponseWriter(ctx.ResponseWriter)
+		ctx.ResponseWriter = gzipResWriter
+	}
+	if size >= 0 {
+		ranges, err := parseRange(rangeReq, size)
+		if err != nil {
+			if err == errNoOverlap {
+				ctx.ResponseWriter.Header().Set("Content-Range", fmt.Sprintf("bytes */%d", size))
+			}
+			return err.Error(), StatusRequestedRangeNotSatisfiable
+
+		}
+		if sumRangesSize(ranges) > size {
+			// The total number of bytes in all the ranges
+			// is larger than the size of the file by
+			// itself, so this is probably an attack, or a
+			// dumb client. Ignore the range request.
+			ranges = nil
+		}
+		switch {
+		case len(ranges) == 1:
+			// RFC 2616, Section 14.16:
+			// "When an HTTP message includes the content of a single
+			// range (for example, a response to a request for a
+			// single range, or to a request for a set of ranges
+			// that overlap without any holes), this content is
+			// transmitted with a Content-Range header, and a
+			// Content-Length header showing the number of bytes
+			// actually transferred.
+			// ...
+			// A response to a request for a single range MUST NOT
+			// be sent using the multipart/byteranges media type."
+			ra := ranges[0]
+			if _, err := content.Seek(ra.start, io.SeekStart); err != nil {
+				return err.Error(), StatusRequestedRangeNotSatisfiable
+			}
+			sendSize = ra.length
+			code = StatusPartialContent
+			ctx.ResponseWriter.Header().Set("Content-Range", ra.contentRange(size))
+		case len(ranges) > 1:
+			sendSize = rangesMIMESize(ranges, ctype, size)
+			code = StatusPartialContent
+
+			pr, pw := io.Pipe()
+			mw := multipart.NewWriter(pw)
+			ctx.ResponseWriter.Header().Set(contentType, "multipart/byteranges; boundary="+mw.Boundary())
+			sendContent = pr
+			defer pr.Close() // cause writing goroutine to fail and exit if CopyN doesn't finish.
+			go func() {
+				for _, ra := range ranges {
+					part, err := mw.CreatePart(ra.mimeHeader(ctype, size))
+					if err != nil {
+						pw.CloseWithError(err)
+						return
+					}
+					if _, err := content.Seek(ra.start, io.SeekStart); err != nil {
+						pw.CloseWithError(err)
+						return
+					}
+					if _, err := io.CopyN(part, content, ra.length); err != nil {
+						pw.CloseWithError(err)
+						return
+					}
+				}
+				mw.Close()
+				pw.Close()
+			}()
+		}
+		ctx.ResponseWriter.Header().Set("Accept-Ranges", "bytes")
+		if ctx.ResponseWriter.Header().Get(contentEncodingHeader) == "" {
+
+			ctx.ResponseWriter.Header().Set(contentLength, strconv.FormatInt(sendSize, 10))
+		}
+	}
+
+	ctx.SetStatusCode(code)
+
+	if ctx.Method() != MethodHead {
+		io.CopyN(ctx.ResponseWriter, sendContent, sendSize)
+	}
+
+	return "", code
+}
+
+// scanETag determines if a syntactically valid ETag is present at s. If so,
+// the ETag and remaining text after consuming ETag is returned. Otherwise,
+// it returns "", "".
+func scanETag(s string) (etag string, remain string) {
+	s = textproto.TrimString(s)
+	start := 0
+	if strings.HasPrefix(s, "W/") {
+		start = 2
+	}
+	if len(s[start:]) < 2 || s[start] != '"' {
+		return "", ""
+	}
+	// ETag is either W/"text" or "text".
+	// See RFC 7232 2.3.
+	for i := start + 1; i < len(s); i++ {
+		c := s[i]
+		switch {
+		// Character values allowed in ETags.
+		case c == 0x21 || c >= 0x23 && c <= 0x7E || c >= 0x80:
+		case c == '"':
+			return string(s[:i+1]), s[i+1:]
+		default:
+			break
+		}
+	}
+	return "", ""
+}
+
+// etagStrongMatch reports whether a and b match using strong ETag comparison.
+// Assumes a and b are valid ETags.
+func etagStrongMatch(a, b string) bool {
+	return a == b && a != "" && a[0] == '"'
+}
+
+// etagWeakMatch reports whether a and b match using weak ETag comparison.
+// Assumes a and b are valid ETags.
+func etagWeakMatch(a, b string) bool {
+	return strings.TrimPrefix(a, "W/") == strings.TrimPrefix(b, "W/")
+}
+
+// condResult is the result of an HTTP request precondition check.
+// See https://tools.ietf.org/html/rfc7232 section 3.
+type condResult int
+
+const (
+	condNone condResult = iota
+	condTrue
+	condFalse
+)
+
+func checkIfMatch(ctx *Context) condResult {
+	im := ctx.Request.Header.Get("If-Match")
+	if im == "" {
+		return condNone
+	}
+	for {
+		im = textproto.TrimString(im)
+		if len(im) == 0 {
+			break
+		}
+		if im[0] == ',' {
+			im = im[1:]
+			continue
+		}
+		if im[0] == '*' {
+			return condTrue
+		}
+		etag, remain := scanETag(im)
+		if etag == "" {
+			break
+		}
+		if etagStrongMatch(etag, ctx.ResponseWriter.Header().Get("Etag")) {
+			return condTrue
+		}
+		im = remain
+	}
+
+	return condFalse
+}
+
+func checkIfUnmodifiedSince(ctx *Context, modtime time.Time) condResult {
+	ius := ctx.Request.Header.Get("If-Unmodified-Since")
+	if ius == "" || isZeroTime(modtime) {
+		return condNone
+	}
+	if t, err := http.ParseTime(ius); err == nil {
+		// The Date-Modified header truncates sub-second precision, so
+		// use mtime < t+1s instead of mtime <= t to check for unmodified.
+		if modtime.Before(t.Add(1 * time.Second)) {
+			return condTrue
+		}
+		return condFalse
+	}
+	return condNone
+}
+
+func checkIfNoneMatch(ctx *Context) condResult {
+	inm := ctx.Request.Header.Get("If-None-Match")
+	if inm == "" {
+		return condNone
+	}
+	buf := inm
+	for {
+		buf = textproto.TrimString(buf)
+		if len(buf) == 0 {
+			break
+		}
+		if buf[0] == ',' {
+			buf = buf[1:]
+		}
+		if buf[0] == '*' {
+			return condFalse
+		}
+		etag, remain := scanETag(buf)
+		if etag == "" {
+			break
+		}
+		if etagWeakMatch(etag, ctx.ResponseWriter.Header().Get("Etag")) {
+			return condFalse
+		}
+		buf = remain
+	}
+	return condTrue
+}
+
+func checkIfModifiedSince(ctx *Context, modtime time.Time) condResult {
+	if ctx.Method() != MethodGet && ctx.Method() != MethodHead {
+		return condNone
+	}
+	ims := ctx.Request.Header.Get("If-Modified-Since")
+	if ims == "" || isZeroTime(modtime) {
+		return condNone
+	}
+	t, err := http.ParseTime(ims)
+	if err != nil {
+		return condNone
+	}
+	// The Date-Modified header truncates sub-second precision, so
+	// use mtime < t+1s instead of mtime <= t to check for unmodified.
+	if modtime.Before(t.Add(1 * time.Second)) {
+		return condFalse
+	}
+	return condTrue
+}
+
+func checkIfRange(ctx *Context, modtime time.Time) condResult {
+	if ctx.Method() != MethodGet {
+		return condNone
+	}
+	ir := ctx.Request.Header.Get("If-Range")
+	if ir == "" {
+		return condNone
+	}
+	etag, _ := scanETag(ir)
+	if etag != "" {
+		if etagStrongMatch(etag, ctx.ResponseWriter.Header().Get("Etag")) {
+			return condTrue
+		}
+		return condFalse
+
+	}
+	// The If-Range value is typically the ETag value, but it may also be
+	// the modtime date. See golang.org/issue/8367.
+	if modtime.IsZero() {
+		return condFalse
+	}
+	t, err := http.ParseTime(ir)
+	if err != nil {
+		return condFalse
+	}
+	if t.Unix() == modtime.Unix() {
+		return condTrue
+	}
+	return condFalse
+}
+
+var unixEpochTime = time.Unix(0, 0)
+
+// isZeroTime reports whether t is obviously unspecified (either zero or Unix()=0).
+func isZeroTime(t time.Time) bool {
+	return t.IsZero() || t.Equal(unixEpochTime)
+}
+
+func setLastModified(ctx *Context, modtime time.Time) {
+	if !isZeroTime(modtime) {
+		ctx.SetHeader("Last-Modified", modtime.UTC().Format(ctx.Framework().Config.TimeFormat))
+	}
+}
+
+func writeNotModified(ctx *Context) {
+	// RFC 7232 section 4.1:
+	// a sender SHOULD NOT generate representation metadata other than the
+	// above listed fields unless said metadata exists for the purpose of
+	// guiding cache updates (e.g., Last-Modified might be useful if the
+	// response does not have an ETag field).
+	h := ctx.ResponseWriter.Header()
+	delete(h, contentType)
+
+	delete(h, contentLength)
+	if h.Get("Etag") != "" {
+		delete(h, "Last-Modified")
+	}
+	ctx.SetStatusCode(StatusNotModified)
+}
+
+// checkPreconditions evaluates request preconditions and reports whether a precondition
+// resulted in sending StatusNotModified or StatusPreconditionFailed.
+func checkPreconditions(ctx *Context, modtime time.Time) (done bool, rangeHeader string) {
+	// This function carefully follows RFC 7232 section 6.
+	ch := checkIfMatch(ctx)
+	if ch == condNone {
+		ch = checkIfUnmodifiedSince(ctx, modtime)
+	}
+	if ch == condFalse {
+
+		ctx.SetStatusCode(StatusPreconditionFailed)
+		return true, ""
+	}
+	switch checkIfNoneMatch(ctx) {
+	case condFalse:
+		if ctx.Method() == MethodGet || ctx.Method() == MethodHead {
+			writeNotModified(ctx)
+			return true, ""
+		}
+		ctx.SetStatusCode(StatusPreconditionFailed)
+		return true, ""
+
+	case condNone:
+		if checkIfModifiedSince(ctx, modtime) == condFalse {
+			writeNotModified(ctx)
+			return true, ""
+		}
+	}
+
+	rangeHeader = ctx.Request.Header.Get("Range")
+	if rangeHeader != "" {
+		if checkIfRange(ctx, modtime) == condFalse {
+			rangeHeader = ""
+		}
+	}
+	return false, rangeHeader
+}
+
+// name is '/'-separated, not filepath.Separator.
+func serveFile(ctx *Context, fs http.FileSystem, name string, redirect bool, showList bool, gzip bool) (string, int) {
+	const indexPage = "/index.html"
+
+	// redirect .../index.html to .../
+	// can't use Redirect() because that would make the path absolute,
+	// which would be a problem running under StripPrefix
+	if strings.HasSuffix(ctx.Request.URL.Path, indexPage) {
+		localRedirect(ctx, "./")
+		return "", StatusMovedPermanently
+	}
+
+	f, err := fs.Open(name)
+	if err != nil {
+		msg, code := toHTTPError(err)
+		return msg, code
+	}
+	defer f.Close()
+
+	d, err := f.Stat()
+	if err != nil {
+		msg, code := toHTTPError(err)
+		return msg, code
+
+	}
+
+	if redirect {
+		// redirect to canonical path: / at end of directory url
+		// ctx.Request.URL.Path always begins with /
+		url := ctx.Request.URL.Path
+		if d.IsDir() {
+			if url[len(url)-1] != '/' {
+				localRedirect(ctx, path.Base(url)+"/")
+				return "", StatusMovedPermanently
+			}
+		} else {
+			if url[len(url)-1] == '/' {
+				localRedirect(ctx, "../"+path.Base(url))
+				return "", StatusMovedPermanently
+			}
+		}
+	}
+
+	// redirect if the directory name doesn't end in a slash
+	if d.IsDir() {
+		url := ctx.Request.URL.Path
+		if url[len(url)-1] != '/' {
+			localRedirect(ctx, path.Base(url)+"/")
+			return "", StatusMovedPermanently
+		}
+	}
+
+	// use contents of index.html for directory, if present
+	if d.IsDir() {
+		index := strings.TrimSuffix(name, "/") + indexPage
+		ff, err := fs.Open(index)
+		if err == nil {
+			defer ff.Close()
+			dd, err := ff.Stat()
+			if err == nil {
+				name = index
+				d = dd
+				f = ff
+			}
+		}
+	}
+
+	// Still a directory? (we didn't find an index.html file)
+	if d.IsDir() {
+		if !showList {
+			return "", StatusForbidden
+		}
+		if checkIfModifiedSince(ctx, d.ModTime()) == condFalse {
+			writeNotModified(ctx)
+			return "", StatusNotModified
+		}
+		ctx.ResponseWriter.Header().Set("Last-Modified", d.ModTime().UTC().Format(ctx.Framework().Config.TimeFormat))
+		return dirList(ctx, f)
+
+	}
+
+	// serveContent will check modification time
+	sizeFunc := func() (int64, error) { return d.Size(), nil }
+	return serveContent(ctx, d.Name(), d.ModTime(), sizeFunc, f, gzip)
+}
+
+// toHTTPError returns a non-specific HTTP error message and status code
+// for a given non-nil error value. It's important that toHTTPError does not
+// actually return err.Error(), since msg and httpStatus are returned to users,
+// and historically Go's ServeContent always returned just "404 Not Found" for
+// all errors. We don't want to start leaking information in error messages.
+func toHTTPError(err error) (msg string, httpStatus int) {
+	if os.IsNotExist(err) {
+		return "404 page not found", StatusNotFound
+	}
+	if os.IsPermission(err) {
+		return "403 Forbidden", StatusForbidden
+	}
+	// Default:
+	return "500 Internal Server Error", StatusInternalServerError
+}
+
+// localRedirect gives a Moved Permanently response.
+// It does not convert relative paths to absolute paths like Redirect does.
+func localRedirect(ctx *Context, newPath string) {
+	if q := ctx.Request.URL.RawQuery; q != "" {
+		newPath += "?" + q
+	}
+	ctx.ResponseWriter.Header().Set("Location", newPath)
+	ctx.SetStatusCode(StatusMovedPermanently)
+}
+
+func containsDotDot(v string) bool {
+	if !strings.Contains(v, "..") {
+		return false
+	}
+	for _, ent := range strings.FieldsFunc(v, isSlashRune) {
+		if ent == ".." {
+			return true
+		}
+	}
+	return false
+}
+
+func isSlashRune(r rune) bool { return r == '/' || r == '\\' }
+
+// httpRange specifies the byte range to be sent to the client.
+type httpRange struct {
+	start, length int64
+}
+
+func (r httpRange) contentRange(size int64) string {
+	return fmt.Sprintf("bytes %d-%d/%d", r.start, r.start+r.length-1, size)
+}
+
+func (r httpRange) mimeHeader(contentType string, size int64) textproto.MIMEHeader {
+	return textproto.MIMEHeader{
+		"Content-Range": {r.contentRange(size)},
+		contentType:     {contentType},
+	}
+}
+
+// parseRange parses a Range header string as per RFC 2616.
+// errNoOverlap is returned if none of the ranges overlap.
+func parseRange(s string, size int64) ([]httpRange, error) {
+	if s == "" {
+		return nil, nil // header not present
+	}
+	const b = "bytes="
+	if !strings.HasPrefix(s, b) {
+		return nil, errors.New("invalid range")
+	}
+	var ranges []httpRange
+	noOverlap := false
+	for _, ra := range strings.Split(s[len(b):], ",") {
+		ra = strings.TrimSpace(ra)
+		if ra == "" {
+			continue
+		}
+		i := strings.Index(ra, "-")
+		if i < 0 {
+			return nil, errors.New("invalid range")
+		}
+		start, end := strings.TrimSpace(ra[:i]), strings.TrimSpace(ra[i+1:])
+		var r httpRange
+		if start == "" {
+			// If no start is specified, end specifies the
+			// range start relative to the end of the file.
+			i, err := strconv.ParseInt(end, 10, 64)
+			if err != nil {
+				return nil, errors.New("invalid range")
+			}
+			if i > size {
+				i = size
+			}
+			r.start = size - i
+			r.length = size - r.start
+		} else {
+			i, err := strconv.ParseInt(start, 10, 64)
+			if err != nil || i < 0 {
+				return nil, errors.New("invalid range")
+			}
+			if i >= size {
+				// If the range begins after the size of the content,
+				// then it does not overlap.
+				noOverlap = true
+				continue
+			}
+			r.start = i
+			if end == "" {
+				// If no end is specified, range extends to end of the file.
+				r.length = size - r.start
+			} else {
+				i, err := strconv.ParseInt(end, 10, 64)
+				if err != nil || r.start > i {
+					return nil, errors.New("invalid range")
+				}
+				if i >= size {
+					i = size - 1
+				}
+				r.length = i - r.start + 1
+			}
+		}
+		ranges = append(ranges, r)
+	}
+	if noOverlap && len(ranges) == 0 {
+		// The specified ranges did not overlap with the content.
+		return nil, errNoOverlap
+	}
+	return ranges, nil
+}
+
+// countingWriter counts how many bytes have been written to it.
+type countingWriter int64
+
+func (w *countingWriter) Write(p []byte) (n int, err error) {
+	*w += countingWriter(len(p))
+	return len(p), nil
+}
+
+// rangesMIMESize returns the number of bytes it takes to encode the
+// provided ranges as a multipart response.
+func rangesMIMESize(ranges []httpRange, contentType string, contentSize int64) (encSize int64) {
+	var w countingWriter
+	mw := multipart.NewWriter(&w)
+	for _, ra := range ranges {
+		mw.CreatePart(ra.mimeHeader(contentType, contentSize))
+		encSize += ra.length
+	}
+	mw.Close()
+	encSize += int64(w)
+	return
+}
+
+func sumRangesSize(ranges []httpRange) (size int64) {
+	for _, ra := range ranges {
+		size += ra.length
+	}
+	return
+}
+
 // typeByExtension returns the MIME type associated with the file extension ext.
 // The extension ext should begin with a leading dot, as in ".html".
 // When ext has no associated type, typeByExtension returns "".

policy.go

@@ -294,6 +294,10 @@ type (
 	// RouterWrapperPolicy is the Policy which enables a wrapper on the top of
 	// the builded Router. Usually it's useful for third-party middleware
 	// when need to wrap the entire application with a middleware like CORS.
+	//
+	// Developers can Adapt more than one RouterWrapper
+	// those wrappers' execution comes from last to first.
+	// That means that the second wrapper will wrap the first, and so on.
 	RouterWrapperPolicy func(w http.ResponseWriter, r *http.Request, next http.HandlerFunc)
 )
 
@@ -364,8 +368,26 @@ func (r RouterBuilderPolicy) Adapt(frame *Policies) {
 }
 
 // Adapt adaps a RouterWrapperPolicy object to the main *Policies.
-func (r RouterWrapperPolicy) Adapt(frame *Policies) {
-	frame.RouterWrapperPolicy = r
+func (rw RouterWrapperPolicy) Adapt(frame *Policies) {
+	if rw != nil {
+		wrapper := rw
+		prevWrapper := frame.RouterWrapperPolicy
+
+		if prevWrapper != nil {
+			nextWrapper := rw
+			wrapper = func(w http.ResponseWriter, r *http.Request, next http.HandlerFunc) {
+				if next != nil {
+					nexthttpFunc := http.HandlerFunc(func(_w http.ResponseWriter, _r *http.Request) {
+						prevWrapper(_w, _r, next)
+					})
+					nextWrapper(w, r, nexthttpFunc)
+				}
+
+			}
+		}
+		frame.RouterWrapperPolicy = wrapper
+	}
+
 }
 
 // RenderPolicy is the type which you can adapt custom renderers

policy_routerwrapper_test.go

@@ -0,0 +1,50 @@
+package iris_test
+
+import (
+	"net/http"
+	"testing"
+
+	. "gopkg.in/kataras/iris.v6"
+	"gopkg.in/kataras/iris.v6/adaptors/httprouter"
+	"gopkg.in/kataras/iris.v6/httptest"
+)
+
+func TestRouterWrapperPolicySimple(t *testing.T) {
+	w1 := RouterWrapperPolicy(func(w http.ResponseWriter, r *http.Request, next http.HandlerFunc) {
+		w.Write([]byte("DATA "))
+		next(w, r) // continue to the main router
+	})
+
+	w2 := RouterWrapperPolicy(func(w http.ResponseWriter, r *http.Request, next http.HandlerFunc) {
+		if r.RequestURI == "/" {
+			next(w, r) // continue to w1
+			return
+		}
+		// else don't execute the router and the handler and fire not found
+		w.WriteHeader(StatusNotFound)
+	})
+
+	app := New()
+	app.Adapt(
+		httprouter.New(),
+		w1, // order matters, second wraps the first and so on, so the last(w2) is responsible to execute the next wrapper (if more than one) and the router
+		w2,
+		// w2 -> w1 -> httprouter -> handler
+	)
+
+	app.OnError(StatusNotFound, func(ctx *Context) {
+		ctx.Writef("not found")
+	})
+
+	app.Get("/", func(ctx *Context) {
+		ctx.Write([]byte("OK"))
+	})
+
+	app.Get("/routerDoesntContinue", func(ctx *Context) {
+
+	})
+
+	e := httptest.New(app, t)
+	e.GET("/").Expect().Status(StatusOK).Body().Equal("DATA OK")
+	e.GET("/routerDoesntContinue").Expect().Status(StatusNotFound)
+}

response_recorder.go

@@ -18,15 +18,14 @@ func acquireResponseRecorder(underline *responseWriter) *ResponseRecorder {
 	w := rrpool.Get().(*ResponseRecorder)
 	w.responseWriter = underline
 	w.headers = underline.Header()
+	w.ResetBody()
 	return w
 }
 
 func releaseResponseRecorder(w *ResponseRecorder) {
-	w.ResetBody()
 	if w.responseWriter != nil {
 		releaseResponseWriter(w.responseWriter)
 	}
-
 	rrpool.Put(w)
 }
 
@@ -124,9 +123,18 @@ func (w *ResponseRecorder) ResetHeaders() {
 	w.headers = w.responseWriter.Header()
 }
 
+// ReseAllHeaders clears all headers, both temp and underline's response writer
+func (w *ResponseRecorder) ReseAllHeaders() {
+	w.headers = http.Header{}
+	h := w.responseWriter.Header()
+	for k := range h {
+		h[k] = nil
+	}
+}
+
 // Reset resets the response body, headers and the status code header
 func (w *ResponseRecorder) Reset() {
-	w.ResetHeaders()
+	w.ReseAllHeaders()
 	w.statusCode = StatusOK
 	w.ResetBody()
 }
@@ -135,9 +143,12 @@ func (w *ResponseRecorder) Reset() {
 // called automatically at the end of each request, see ReleaseCtx
 func (w *ResponseRecorder) flushResponse() {
 	if w.headers != nil {
+		h := w.responseWriter.Header()
+
 		for k, values := range w.headers {
+			h[k] = nil
 			for i := range values {
-				w.responseWriter.Header().Add(k, values[i])
+				h.Add(k, values[i])
 			}
 		}
 	}

response_writer.go

@@ -13,7 +13,9 @@ import (
 
 type gzipResponseWriter struct {
 	ResponseWriter
-	gzipWriter *gzip.Writer
+	gzipWriter *gzip.Writer // it contains the underline writer too
+	chunks     []byte
+	disabled   bool
 }
 
 var gzpool = sync.Pool{New: func() interface{} { return &gzipResponseWriter{} }}
@@ -22,6 +24,8 @@ func acquireGzipResponseWriter(underline ResponseWriter) *gzipResponseWriter {
 	w := gzpool.Get().(*gzipResponseWriter)
 	w.ResponseWriter = underline
 	w.gzipWriter = acquireGzipWriter(w.ResponseWriter)
+	w.chunks = w.chunks[0:0]
+	w.disabled = false
 	return w
 }
 
@@ -32,7 +36,32 @@ func releaseGzipResponseWriter(w *gzipResponseWriter) {
 
 // Write compresses and writes that data to the underline response writer
 func (w *gzipResponseWriter) Write(contents []byte) (int, error) {
-	return w.gzipWriter.Write(contents)
+	// save the contents to serve them (only gzip data here)
+	w.chunks = append(w.chunks, contents...)
+	return len(w.chunks), nil
+}
+
+func (w *gzipResponseWriter) flushResponse() {
+	if w.disabled {
+		w.ResponseWriter.Write(w.chunks)
+	} else {
+		// if it's not disable write all chunks gzip compressed
+		w.gzipWriter.Write(w.chunks) // it writes to the underline responseWriter (look acquireGzipResponseWriter)
+	}
+	w.ResponseWriter.flushResponse()
+}
+
+func (w *gzipResponseWriter) ResetBody() {
+	w.chunks = w.chunks[0:0]
+}
+
+func (w *gzipResponseWriter) Disable() {
+	w.disabled = true
+}
+
+func (w *gzipResponseWriter) releaseMe() {
+	releaseGzipResponseWriter(w)
+	w.ResponseWriter.releaseMe()
 }
 
 var rpool = sync.Pool{New: func() interface{} { return &responseWriter{statusCode: StatusOK} }}

router.go

@@ -348,16 +348,6 @@ func (router *Router) Any(registeredPath string, handlersFn ...HandlerFunc) {
 	}
 }
 
-// if / then returns /*wildcard or /something then /something/*wildcard
-// if empty then returns /*wildcard too
-func validateWildcard(reqPath string, paramName string) string {
-	if reqPath[len(reqPath)-1] != slashByte {
-		reqPath += slash
-	}
-	reqPath += "*" + paramName
-	return reqPath
-}
-
 func (router *Router) registerResourceRoute(reqPath string, h HandlerFunc) RouteInfo {
 	router.Head(reqPath, h)
 	return router.Get(reqPath, h)
@@ -582,26 +572,12 @@ func (router *Router) StaticHandler(reqPath string, systemPath string, showList
 		path = fullpath[dotWSlashIdx+1:]
 	}
 
-	h := NewStaticHandlerBuilder(systemPath).
+	return NewStaticHandlerBuilder(systemPath).
 		Path(path).
 		Listing(showList).
 		Gzip(enableGzip).
 		Except(exceptRoutes...).
 		Build()
-
-	managedStaticHandler := func(ctx *Context) {
-		h(ctx)
-		prevStatusCode := ctx.ResponseWriter.StatusCode()
-		if prevStatusCode >= 400 { // we have an error
-			// fire the custom error handler
-			router.Errors.Fire(prevStatusCode, ctx)
-		}
-		// go to the next middleware
-		if ctx.Pos < len(ctx.Middleware)-1 {
-			ctx.Next()
-		}
-	}
-	return managedStaticHandler
 }
 
 // StaticWeb returns a handler that serves HTTP requests
@@ -623,7 +599,7 @@ func (router *Router) StaticHandler(reqPath string, systemPath string, showList
 func (router *Router) StaticWeb(reqPath string, systemPath string, exceptRoutes ...RouteInfo) RouteInfo {
 	h := router.StaticHandler(reqPath, systemPath, false, false, exceptRoutes...)
 	paramName := "file"
-	routePath := validateWildcard(reqPath, paramName)
+	routePath := router.Context.Framework().RouteWildcardPath(reqPath, paramName)
 	handler := func(ctx *Context) {
 		h(ctx)
 		if fname := ctx.Param(paramName); fname != "" {
@@ -659,10 +635,22 @@ func (router *Router) Layout(tmplLayoutFile string) *Router {
 	return router
 }
 
-// OnError registers a custom http error handler
-func (router *Router) OnError(statusCode int, handlerFn HandlerFunc) {
+// OnError registers a custom http error handler.
+// Accepts the status code which the 'handlerFn' should be fired,
+// third parameter is OPTIONAL, if setted then the 'handlerFn' will be executed
+// only when this regex expression will be validated and matched to the ctx.Request.RequestURI,
+// keep note that it will compare the whole request path but the error handler owns to this Party,
+// this gives developers power tooling.
+//
+// Each party's static path prefix can have a set of its own error handlers,
+// this works by wrapping the error handlers, so if a party doesn't needs a custom error handler,
+// then it will execute the root's one (if setted, otherwise the framework creates one at runtime).
+func (router *Router) OnError(statusCode int, handlerFn HandlerFunc, rgexp ...string) {
 	staticPath := router.Context.Framework().policies.RouterReversionPolicy.StaticPath(router.relativePath)
-
+	expr := ""
+	if len(rgexp) > 0 {
+		expr = rgexp[0]
+	}
 	if staticPath == "/" {
 		router.Errors.Register(statusCode, handlerFn) // register the user-specific error message, as the global error handler, for now.
 		return
@@ -676,9 +664,12 @@ func (router *Router) OnError(statusCode int, handlerFn HandlerFunc) {
 	// get the previous
 	prevErrHandler := router.Errors.GetOrRegister(statusCode)
 
-	func(statusCode int, staticPath string, prevErrHandler Handler, newHandler Handler) { // to separate the logic
+	func(statusCode int, staticPath string, prevErrHandler Handler, newHandler Handler, expr string) { // to separate the logic
 		errHandler := HandlerFunc(func(ctx *Context) {
-			if strings.HasPrefix(ctx.Path(), staticPath) { // yes the user should use OnError from longest to lower static path's length in order this to work, so we can find another way, like a builder on the end.
+
+			path := ctx.Request.RequestURI // This is relative to: http://support.iris-go.com/d/17-fallback-handler-for-non-matched-routes
+			// note: NOT Request.URL.Path (even if it's not overriden by static handlers.)
+			if strings.HasPrefix(path, staticPath) { // yes the user should use OnError from longest to lower static path's length in order this to work, so we can find another way, like a builder on the end.
 				newHandler.Serve(ctx)
 				return
 			}
@@ -686,9 +677,8 @@ func (router *Router) OnError(statusCode int, handlerFn HandlerFunc) {
 			prevErrHandler.Serve(ctx)
 		})
 
-		router.Errors.Register(statusCode, errHandler)
-	}(statusCode, staticPath, prevErrHandler, handlerFn)
-
+		router.Errors.RegisterRegex(statusCode, errHandler, expr)
+	}(statusCode, staticPath, prevErrHandler, handlerFn, expr)
 }
 
 // EmitError fires a custom http error handler to the client

status.go

@@ -1,6 +1,7 @@
 package iris
 
 import (
+	"regexp"
 	"sync"
 )
 
@@ -153,7 +154,7 @@ type ErrorHandlers struct {
 	mu       sync.RWMutex
 }
 
-// Register registers a handler to a http status
+// Register registers a handler to a http status.
 func (e *ErrorHandlers) Register(statusCode int, handler Handler) {
 	e.mu.Lock()
 	if e.handlers == nil {
@@ -171,6 +172,39 @@ func (e *ErrorHandlers) Register(statusCode int, handler Handler) {
 	e.mu.Unlock()
 }
 
+// RegisterRegex same as Register but it receives a third parameter which is the regex expression
+// which is running versus the REQUESTED PATH, i.e "/api/users/42".
+//
+// If the match against the REQUEST PATH and the 'expr' failed then
+// the previous registered error handler on this specific 'statusCode' will be executed.
+//
+// Returns an error if regexp.Compile failed, nothing special.
+func (e *ErrorHandlers) RegisterRegex(statusCode int, handler Handler, expr string) error {
+	// if expr is empty, skip the validation and set the error handler as it's
+	if expr == "" {
+		e.Register(statusCode, handler)
+		return nil
+	}
+	r, err := regexp.Compile(expr)
+	if err != nil {
+		return err
+	}
+
+	prevHandler := e.GetOrRegister(statusCode)
+
+	e.Register(statusCode, HandlerFunc(func(ctx *Context) {
+		requestPath := ctx.Request.RequestURI
+
+		if r.MatchString(requestPath) {
+			handler.Serve(ctx)
+			return
+		}
+		prevHandler.Serve(ctx)
+	}))
+
+	return nil
+}
+
 // Get returns the handler which is responsible for
 // this 'statusCode' http error.
 func (e *ErrorHandlers) Get(statusCode int) Handler {

status_test.go

@@ -103,3 +103,63 @@ func TestStatusMethodNotAllowed(t *testing.T) {
 	testStatusMethodNotAllowed(httprouter.New(), t)
 	testStatusMethodNotAllowed(gorillamux.New(), t)
 }
+
+func testRegisterRegex(routerPolicy iris.Policy, t *testing.T) {
+
+	app := iris.New()
+	app.Adapt(routerPolicy)
+
+	h := func(ctx *iris.Context) {
+		ctx.WriteString(ctx.Method())
+	}
+
+	app.OnError(iris.StatusNotFound, func(ctx *iris.Context) {
+		ctx.WriteString("root 404")
+	})
+
+	staticP := app.Party("/static")
+	{
+		// or app.Errors... same thing
+		staticP.Errors.RegisterRegex(iris.StatusNotFound, iris.HandlerFunc(func(ctx *iris.Context) {
+			ctx.WriteString("/static 404")
+		}), "/static/[0-9]+")
+
+		// simulate a StaticHandler or StaticWeb simple behavior
+		// in order to get a not found error from a wildcard path registered on the root path of the "/static".
+		// Note:
+		// RouteWildcardPath when you want to work on all router adaptors:httprouter=> *file, gorillamux=> {file:.*}
+		staticP.Get(app.RouteWildcardPath("/", "file"), func(ctx *iris.Context) {
+
+			i, err := ctx.ParamIntWildcard("file")
+			if i > 0 || err == nil {
+				// this handler supposed to accept only strings, for the sake of the test.
+				ctx.EmitError(iris.StatusNotFound)
+				return
+			}
+
+			ctx.SetStatusCode(iris.StatusOK)
+		})
+
+	}
+
+	app.Get("/mypath", h)
+
+	e := httptest.New(app, t)
+	// print("-------------------TESTING ")
+	// println(app.Config.Other[iris.RouterNameConfigKey].(string) + "-------------------")
+
+	e.GET("/mypath").Expect().Status(iris.StatusOK).Body().Equal("GET")
+	e.GET("/rootnotfound").Expect().Status(iris.StatusNotFound).Body().Equal("root 404")
+
+	// test found on party
+	e.GET("/static/itshouldbeok").Expect().Status(iris.StatusOK)
+	// test no found on party ( by putting at least one integer after /static)
+	e.GET("/static/42").Expect().Status(iris.StatusNotFound).Body().Equal("/static 404")
+
+	// println("-------------------------------------------------------")
+}
+
+func TestRegisterRegex(t *testing.T) {
+	testRegisterRegex(httprouter.New(), t)
+	testRegisterRegex(gorillamux.New(), t)
+}