harness-drone/vendor/github.com/dimfeld/httptreemux/group.go
2017-07-31 15:15:05 -04:00

195 lines
6.4 KiB
Go

package httptreemux
import (
"fmt"
"net/url"
"strings"
)
type Group struct {
path string
mux *TreeMux
}
// Add a sub-group to this group
func (g *Group) NewGroup(path string) *Group {
if len(path) < 1 {
panic("Group path must not be empty")
}
checkPath(path)
path = g.path + path
//Don't want trailing slash as all sub-paths start with slash
if path[len(path)-1] == '/' {
path = path[:len(path)-1]
}
return &Group{path, g.mux}
}
// Path elements starting with : indicate a wildcard in the path. A wildcard will only match on a
// single path segment. That is, the pattern `/post/:postid` will match on `/post/1` or `/post/1/`,
// but not `/post/1/2`.
//
// A path element starting with * is a catch-all, whose value will be a string containing all text
// in the URL matched by the wildcards. For example, with a pattern of `/images/*path` and a
// requested URL `images/abc/def`, path would contain `abc/def`.
//
// # Routing Rule Priority
//
// The priority rules in the router are simple.
//
// 1. Static path segments take the highest priority. If a segment and its subtree are able to match the URL, that match is returned.
//
// 2. Wildcards take second priority. For a particular wildcard to match, that wildcard and its subtree must match the URL.
//
// 3. Finally, a catch-all rule will match when the earlier path segments have matched, and none of the static or wildcard conditions have matched. Catch-all rules must be at the end of a pattern.
//
// So with the following patterns, we'll see certain matches:
// router = httptreemux.New()
// router.GET("/:page", pageHandler)
// router.GET("/:year/:month/:post", postHandler)
// router.GET("/:year/:month", archiveHandler)
// router.GET("/images/*path", staticHandler)
// router.GET("/favicon.ico", staticHandler)
//
// /abc will match /:page
// /2014/05 will match /:year/:month
// /2014/05/really-great-blog-post will match /:year/:month/:post
// /images/CoolImage.gif will match /images/*path
// /images/2014/05/MayImage.jpg will also match /images/*path, with all the text after /images stored in the variable path.
// /favicon.ico will match /favicon.ico
//
// # Trailing Slashes
//
// The router has special handling for paths with trailing slashes. If a pattern is added to the
// router with a trailing slash, any matches on that pattern without a trailing slash will be
// redirected to the version with the slash. If a pattern does not have a trailing slash, matches on
// that pattern with a trailing slash will be redirected to the version without.
//
// The trailing slash flag is only stored once for a pattern. That is, if a pattern is added for a
// method with a trailing slash, all other methods for that pattern will also be considered to have a
// trailing slash, regardless of whether or not it is specified for those methods too.
//
// This behavior can be turned off by setting TreeMux.RedirectTrailingSlash to false. By
// default it is set to true. The specifics of the redirect depend on RedirectBehavior.
//
// One exception to this rule is catch-all patterns. By default, trailing slash redirection is
// disabled on catch-all patterns, since the structure of the entire URL and the desired patterns
// can not be predicted. If trailing slash removal is desired on catch-all patterns, set
// TreeMux.RemoveCatchAllTrailingSlash to true.
//
// router = httptreemux.New()
// router.GET("/about", pageHandler)
// router.GET("/posts/", postIndexHandler)
// router.POST("/posts", postFormHandler)
//
// GET /about will match normally.
// GET /about/ will redirect to /about.
// GET /posts will redirect to /posts/.
// GET /posts/ will match normally.
// POST /posts will redirect to /posts/, because the GET method used a trailing slash.
func (g *Group) Handle(method string, path string, handler HandlerFunc) {
g.mux.mutex.Lock()
defer g.mux.mutex.Unlock()
addSlash := false
addOne := func(thePath string) {
node := g.mux.root.addPath(thePath[1:], nil, false)
if addSlash {
node.addSlash = true
}
node.setHandler(method, handler, false)
if g.mux.HeadCanUseGet && method == "GET" && node.leafHandler["HEAD"] == nil {
node.setHandler("HEAD", handler, true)
}
}
checkPath(path)
path = g.path + path
if len(path) == 0 {
panic("Cannot map an empty path")
}
if len(path) > 1 && path[len(path)-1] == '/' && g.mux.RedirectTrailingSlash {
addSlash = true
path = path[:len(path)-1]
}
if g.mux.EscapeAddedRoutes {
u, err := url.ParseRequestURI(path)
if err != nil {
panic("URL parsing error " + err.Error() + " on url " + path)
}
escapedPath := unescapeSpecial(u.String())
if escapedPath != path {
addOne(escapedPath)
}
}
addOne(path)
}
// Syntactic sugar for Handle("GET", path, handler)
func (g *Group) GET(path string, handler HandlerFunc) {
g.Handle("GET", path, handler)
}
// Syntactic sugar for Handle("POST", path, handler)
func (g *Group) POST(path string, handler HandlerFunc) {
g.Handle("POST", path, handler)
}
// Syntactic sugar for Handle("PUT", path, handler)
func (g *Group) PUT(path string, handler HandlerFunc) {
g.Handle("PUT", path, handler)
}
// Syntactic sugar for Handle("DELETE", path, handler)
func (g *Group) DELETE(path string, handler HandlerFunc) {
g.Handle("DELETE", path, handler)
}
// Syntactic sugar for Handle("PATCH", path, handler)
func (g *Group) PATCH(path string, handler HandlerFunc) {
g.Handle("PATCH", path, handler)
}
// Syntactic sugar for Handle("HEAD", path, handler)
func (g *Group) HEAD(path string, handler HandlerFunc) {
g.Handle("HEAD", path, handler)
}
// Syntactic sugar for Handle("OPTIONS", path, handler)
func (g *Group) OPTIONS(path string, handler HandlerFunc) {
g.Handle("OPTIONS", path, handler)
}
func checkPath(path string) {
// All non-empty paths must start with a slash
if len(path) > 0 && path[0] != '/' {
panic(fmt.Sprintf("Path %s must start with slash", path))
}
}
func unescapeSpecial(s string) string {
// Look for sequences of \*, *, and \: that were escaped, and undo some of that escaping.
// Unescape /* since it references a wildcard token.
s = strings.Replace(s, "/%2A", "/*", -1)
// Unescape /\: since it references a literal colon
s = strings.Replace(s, "/%5C:", "/\\:", -1)
// Replace escaped /\\: with /\:
s = strings.Replace(s, "/%5C%5C:", "/%5C:", -1)
// Replace escaped /\* with /*
s = strings.Replace(s, "/%5C%2A", "/%2A", -1)
// Replace escaped /\\* with /\*
s = strings.Replace(s, "/%5C%5C%2A", "/%5C%2A", -1)
return s
}