Hold matched route full path in the Context (#1826)

* Return nodeValue from getValue method

* Hold route full path in the Context

* Add small example

README.md

@@ -252,6 +252,11 @@ func main() {
 		c.String(http.StatusOK, message)
 	})
 
+	// For each matched request Context will hold the route definition
+	router.POST("/user/:name/*action", func(c *gin.Context) {
+		c.FullPath() == "/user/:name/*action" // true
+	})
+
 	router.Run(":8080")
 }
 ```

context.go

@@ -48,6 +48,7 @@ type Context struct {
 	Params   Params
 	handlers HandlersChain
 	index    int8
+	fullPath string
 
 	engine *Engine
 
@@ -70,6 +71,7 @@ func (c *Context) reset() {
 	c.Params = c.Params[0:0]
 	c.handlers = nil
 	c.index = -1
+	c.fullPath = ""
 	c.Keys = nil
 	c.Errors = c.Errors[0:0]
 	c.Accepted = nil
@@ -111,6 +113,15 @@ func (c *Context) Handler() HandlerFunc {
 	return c.handlers.Last()
 }
 
+// FullPath returns a matched route full path. For not found routes
+// returns an empty string.
+//     router.GET("/user/:id", func(c *gin.Context) {
+//         c.FullPath() == "/user/:id" // true
+//     })
+func (c *Context) FullPath() string {
+	return c.fullPath
+}
+
 /************************************/
 /*********** FLOW CONTROL ***********/
 /************************************/

gin.go

@@ -252,6 +252,7 @@ func (engine *Engine) addRoute(method, path string, handlers HandlersChain) {
 	root := engine.trees.get(method)
 	if root == nil {
 		root = new(node)
+		root.fullPath = "/"
 		engine.trees = append(engine.trees, methodTree{method: method, root: root})
 	}
 	root.addRoute(path, handlers)
@@ -382,16 +383,17 @@ func (engine *Engine) handleHTTPRequest(c *Context) {
 		}
 		root := t[i].root
 		// Find route in tree
-		handlers, params, tsr := root.getValue(rPath, c.Params, unescape)
-		if handlers != nil {
-			c.handlers = handlers
-			c.Params = params
+		value := root.getValue(rPath, c.Params, unescape)
+		if value.handlers != nil {
+			c.handlers = value.handlers
+			c.Params = value.params
+			c.fullPath = value.fullPath
 			c.Next()
 			c.writermem.WriteHeaderNow()
 			return
 		}
 		if httpMethod != "CONNECT" && rPath != "/" {
-			if tsr && engine.RedirectTrailingSlash {
+			if value.tsr && engine.RedirectTrailingSlash {
 				redirectTrailingSlash(c)
 				return
 			}
@@ -407,7 +409,7 @@ func (engine *Engine) handleHTTPRequest(c *Context) {
 			if tree.method == httpMethod {
 				continue
 			}
-			if handlers, _, _ := tree.root.getValue(rPath, nil, unescape); handlers != nil {
+			if value := tree.root.getValue(rPath, nil, unescape); value.handlers != nil {
 				c.handlers = engine.allNoMethod
 				serveError(c, http.StatusMethodNotAllowed, default405Body)
 				return

routes_test.go

@@ -554,3 +554,38 @@ func TestRouteServeErrorWithWriteHeader(t *testing.T) {
 	assert.Equal(t, 421, w.Code)
 	assert.Equal(t, 0, w.Body.Len())
 }
+
+func TestRouteContextHoldsFullPath(t *testing.T) {
+	router := New()
+
+	// Test routes
+	routes := []string{
+		"/",
+		"/simple",
+		"/project/:name",
+		"/project/:name/build/*params",
+	}
+
+	for _, route := range routes {
+		actualRoute := route
+		router.GET(route, func(c *Context) {
+			// For each defined route context should contain its full path
+			assert.Equal(t, actualRoute, c.FullPath())
+			c.AbortWithStatus(http.StatusOK)
+		})
+	}
+
+	for _, route := range routes {
+		w := performRequest(router, "GET", route)
+		assert.Equal(t, http.StatusOK, w.Code)
+	}
+
+	// Test not found
+	router.Use(func(c *Context) {
+		// For not found routes full path is empty
+		assert.Equal(t, "", c.FullPath())
+	})
+
+	w := performRequest(router, "GET", "/not-found")
+	assert.Equal(t, http.StatusNotFound, w.Code)
+}

tree.go

@@ -94,6 +94,7 @@ type node struct {
 	nType     nodeType
 	maxParams uint8
 	wildChild bool
+	fullPath  string
 }
 
 // increments priority of the given child and reorders if necessary.
@@ -154,6 +155,7 @@ func (n *node) addRoute(path string, handlers HandlersChain) {
 					children:  n.children,
 					handlers:  n.handlers,
 					priority:  n.priority - 1,
+					fullPath:  fullPath,
 				}
 
 				// Update maxParams (max of all children)
@@ -229,6 +231,7 @@ func (n *node) addRoute(path string, handlers HandlersChain) {
 					n.indices += string([]byte{c})
 					child := &node{
 						maxParams: numParams,
+						fullPath:  fullPath,
 					}
 					n.children = append(n.children, child)
 					n.incrementChildPrio(len(n.indices) - 1)
@@ -296,6 +299,7 @@ func (n *node) insertChild(numParams uint8, path string, fullPath string, handle
 			child := &node{
 				nType:     param,
 				maxParams: numParams,
+				fullPath:  fullPath,
 			}
 			n.children = []*node{child}
 			n.wildChild = true
@@ -312,6 +316,7 @@ func (n *node) insertChild(numParams uint8, path string, fullPath string, handle
 				child := &node{
 					maxParams: numParams,
 					priority:  1,
+					fullPath:  fullPath,
 				}
 				n.children = []*node{child}
 				n = child
@@ -339,6 +344,7 @@ func (n *node) insertChild(numParams uint8, path string, fullPath string, handle
 				wildChild: true,
 				nType:     catchAll,
 				maxParams: 1,
+				fullPath:  fullPath,
 			}
 			n.children = []*node{child}
 			n.indices = string(path[i])
@@ -352,6 +358,7 @@ func (n *node) insertChild(numParams uint8, path string, fullPath string, handle
 				maxParams: 1,
 				handlers:  handlers,
 				priority:  1,
+				fullPath:  fullPath,
 			}
 			n.children = []*node{child}
 
@@ -364,13 +371,21 @@ func (n *node) insertChild(numParams uint8, path string, fullPath string, handle
 	n.handlers = handlers
 }
 
+// nodeValue holds return values of (*Node).getValue method
+type nodeValue struct {
+	handlers HandlersChain
+	params   Params
+	tsr      bool
+	fullPath string
+}
+
 // getValue returns the handle registered with the given path (key). The values of
 // wildcards are saved to a map.
 // If no handle can be found, a TSR (trailing slash redirect) recommendation is
 // made if a handle exists with an extra (without the) trailing slash for the
 // given path.
-func (n *node) getValue(path string, po Params, unescape bool) (handlers HandlersChain, p Params, tsr bool) {
-	p = po
+func (n *node) getValue(path string, po Params, unescape bool) (value nodeValue) {
+	value.params = po
 walk: // Outer loop for walking the tree
 	for {
 		if len(path) > len(n.path) {
@@ -391,7 +406,7 @@ walk: // Outer loop for walking the tree
 					// Nothing found.
 					// We can recommend to redirect to the same URL without a
 					// trailing slash if a leaf exists for that path.
-					tsr = path == "/" && n.handlers != nil
+					value.tsr = path == "/" && n.handlers != nil
 					return
 				}
 
@@ -406,20 +421,20 @@ walk: // Outer loop for walking the tree
 					}
 
 					// save param value
-					if cap(p) < int(n.maxParams) {
-						p = make(Params, 0, n.maxParams)
+					if cap(value.params) < int(n.maxParams) {
+						value.params = make(Params, 0, n.maxParams)
 					}
-					i := len(p)
-					p = p[:i+1] // expand slice within preallocated capacity
-					p[i].Key = n.path[1:]
+					i := len(value.params)
+					value.params = value.params[:i+1] // expand slice within preallocated capacity
+					value.params[i].Key = n.path[1:]
 					val := path[:end]
 					if unescape {
 						var err error
-						if p[i].Value, err = url.QueryUnescape(val); err != nil {
-							p[i].Value = val // fallback, in case of error
+						if value.params[i].Value, err = url.QueryUnescape(val); err != nil {
+							value.params[i].Value = val // fallback, in case of error
 						}
 					} else {
-						p[i].Value = val
+						value.params[i].Value = val
 					}
 
 					// we need to go deeper!
@@ -431,40 +446,42 @@ walk: // Outer loop for walking the tree
 						}
 
 						// ... but we can't
-						tsr = len(path) == end+1
+						value.tsr = len(path) == end+1
 						return
 					}
 
-					if handlers = n.handlers; handlers != nil {
+					if value.handlers = n.handlers; value.handlers != nil {
+						value.fullPath = n.fullPath
 						return
 					}
 					if len(n.children) == 1 {
 						// No handle found. Check if a handle for this path + a
 						// trailing slash exists for TSR recommendation
 						n = n.children[0]
-						tsr = n.path == "/" && n.handlers != nil
+						value.tsr = n.path == "/" && n.handlers != nil
 					}
 
 					return
 
 				case catchAll:
 					// save param value
-					if cap(p) < int(n.maxParams) {
-						p = make(Params, 0, n.maxParams)
+					if cap(value.params) < int(n.maxParams) {
+						value.params = make(Params, 0, n.maxParams)
 					}
-					i := len(p)
-					p = p[:i+1] // expand slice within preallocated capacity
-					p[i].Key = n.path[2:]
+					i := len(value.params)
+					value.params = value.params[:i+1] // expand slice within preallocated capacity
+					value.params[i].Key = n.path[2:]
 					if unescape {
 						var err error
-						if p[i].Value, err = url.QueryUnescape(path); err != nil {
-							p[i].Value = path // fallback, in case of error
+						if value.params[i].Value, err = url.QueryUnescape(path); err != nil {
+							value.params[i].Value = path // fallback, in case of error
 						}
 					} else {
-						p[i].Value = path
+						value.params[i].Value = path
 					}
 
-					handlers = n.handlers
+					value.handlers = n.handlers
+					value.fullPath = n.fullPath
 					return
 
 				default:
@@ -474,12 +491,13 @@ walk: // Outer loop for walking the tree
 		} else if path == n.path {
 			// We should have reached the node containing the handle.
 			// Check if this node has a handle registered.
-			if handlers = n.handlers; handlers != nil {
+			if value.handlers = n.handlers; value.handlers != nil {
+				value.fullPath = n.fullPath
 				return
 			}
 
 			if path == "/" && n.wildChild && n.nType != root {
-				tsr = true
+				value.tsr = true
 				return
 			}
 
@@ -488,7 +506,7 @@ walk: // Outer loop for walking the tree
 			for i := 0; i < len(n.indices); i++ {
 				if n.indices[i] == '/' {
 					n = n.children[i]
-					tsr = (len(n.path) == 1 && n.handlers != nil) ||
+					value.tsr = (len(n.path) == 1 && n.handlers != nil) ||
 						(n.nType == catchAll && n.children[0].handlers != nil)
 					return
 				}
@@ -499,7 +517,7 @@ walk: // Outer loop for walking the tree
 
 		// Nothing found. We can recommend to redirect to the same URL with an
 		// extra trailing slash if a leaf exists for that path
-		tsr = (path == "/") ||
+		value.tsr = (path == "/") ||
 			(len(n.path) == len(path)+1 && n.path[len(path)] == '/' &&
 				path == n.path[:len(n.path)-1] && n.handlers != nil)
 		return

tree_test.go

@@ -35,22 +35,22 @@ func checkRequests(t *testing.T, tree *node, requests testRequests, unescapes ..
 	}
 
 	for _, request := range requests {
-		handler, ps, _ := tree.getValue(request.path, nil, unescape)
+		value := tree.getValue(request.path, nil, unescape)
 
-		if handler == nil {
+		if value.handlers == nil {
 			if !request.nilHandler {
 				t.Errorf("handle mismatch for route '%s': Expected non-nil handle", request.path)
 			}
 		} else if request.nilHandler {
 			t.Errorf("handle mismatch for route '%s': Expected nil handle", request.path)
 		} else {
-			handler[0](nil)
+			value.handlers[0](nil)
 			if fakeHandlerValue != request.route {
 				t.Errorf("handle mismatch for route '%s': Wrong handle (%s != %s)", request.path, fakeHandlerValue, request.route)
 			}
 		}
 
-		if !reflect.DeepEqual(ps, request.ps) {
+		if !reflect.DeepEqual(value.params, request.ps) {
 			t.Errorf("Params mismatch for route '%s'", request.path)
 		}
 	}
@@ -454,10 +454,10 @@ func TestTreeTrailingSlashRedirect(t *testing.T) {
 		"/doc/",
 	}
 	for _, route := range tsrRoutes {
-		handler, _, tsr := tree.getValue(route, nil, false)
-		if handler != nil {
+		value := tree.getValue(route, nil, false)
+		if value.handlers != nil {
 			t.Fatalf("non-nil handler for TSR route '%s", route)
-		} else if !tsr {
+		} else if !value.tsr {
 			t.Errorf("expected TSR recommendation for route '%s'", route)
 		}
 	}
@@ -471,10 +471,10 @@ func TestTreeTrailingSlashRedirect(t *testing.T) {
 		"/api/world/abc",
 	}
 	for _, route := range noTsrRoutes {
-		handler, _, tsr := tree.getValue(route, nil, false)
-		if handler != nil {
+		value := tree.getValue(route, nil, false)
+		if value.handlers != nil {
 			t.Fatalf("non-nil handler for No-TSR route '%s", route)
-		} else if tsr {
+		} else if value.tsr {
 			t.Errorf("expected no TSR recommendation for route '%s'", route)
 		}
 	}
@@ -490,10 +490,10 @@ func TestTreeRootTrailingSlashRedirect(t *testing.T) {
 		t.Fatalf("panic inserting test route: %v", recv)
 	}
 
-	handler, _, tsr := tree.getValue("/", nil, false)
-	if handler != nil {
+	value := tree.getValue("/", nil, false)
+	if value.handlers != nil {
 		t.Fatalf("non-nil handler")
-	} else if tsr {
+	} else if value.tsr {
 		t.Errorf("expected no TSR recommendation")
 	}
 }