Add API call to get a channel by its name (#4700)

* add api for getByChannelName

* add tests

* fix test

* rename and tests

* check for permissions and test

api/channel.go

@@ -31,6 +31,7 @@ func InitChannel() {
 	BaseRoutes.Channels.Handle("/update_purpose", ApiUserRequired(updateChannelPurpose)).Methods("POST")
 	BaseRoutes.Channels.Handle("/update_notify_props", ApiUserRequired(updateNotifyProps)).Methods("POST")
 	BaseRoutes.Channels.Handle("/autocomplete", ApiUserRequired(autocompleteChannels)).Methods("GET")
+	BaseRoutes.Channels.Handle("/name/{channel_name:[A-Za-z0-9_-]+}", ApiUserRequired(getChannelByName)).Methods("GET")
 
 	BaseRoutes.NeedChannelName.Handle("/join", ApiUserRequired(join)).Methods("POST")
 
@@ -953,6 +954,37 @@ func getChannel(c *Context, w http.ResponseWriter, r *http.Request) {
 
 }
 
+func getChannelByName(c *Context, w http.ResponseWriter, r *http.Request) {
+	params := mux.Vars(r)
+	channelname := params["channel_name"]
+
+	cchan := Srv.Store.Channel().GetByName(c.TeamId, channelname)
+
+	if cresult := <-cchan; cresult.Err != nil {
+		c.Err = cresult.Err
+		return
+	} else {
+		data := &model.Channel{}
+		data = cresult.Data.(*model.Channel)
+
+		if !HasPermissionToChannelContext(c, data.Id, model.PERMISSION_READ_CHANNEL) {
+			return
+		}
+
+		if data.TeamId != c.TeamId && data.Type != model.CHANNEL_DIRECT {
+			c.Err = model.NewLocAppError("getChannel", "api.channel.get_channel.wrong_team.app_error", map[string]interface{}{"ChannelName": channelname, "TeamId": c.TeamId}, "")
+			return
+		}
+
+		if HandleEtag(data.Etag(), w, r) {
+			return
+		} else {
+			w.Header().Set(model.HEADER_ETAG_SERVER, data.Etag())
+			w.Write([]byte(data.ToJson()))
+		}
+	}
+}
+
 func getChannelStats(c *Context, w http.ResponseWriter, r *http.Request) {
 	params := mux.Vars(r)
 	id := params["channel_id"]

api/channel_test.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/mattermost/platform/model"
+	"github.com/mattermost/platform/store"
 	"github.com/mattermost/platform/utils"
 )
 
@@ -1632,3 +1633,30 @@ func TestAutocompleteChannels(t *testing.T) {
 		t.Fatal("should have failed - bad team id")
 	}
 }
+
+func TestGetChannelByName(t *testing.T) {
+	th := Setup().InitBasic()
+	Client := th.BasicClient
+
+	if _, err := Client.GetChannelByName(th.BasicChannel.Name); err != nil {
+		t.Fatal("Failed to get channel")
+	}
+
+	if _, err := Client.GetChannelByName("InvalidChannelName"); err == nil {
+		t.Fatal("Failed to get team")
+	}
+
+	Client.Must(Client.Logout())
+
+	user2 := &model.User{Email: "success+" + model.NewId() + "@simulator.amazonses.com", Nickname: "Jabba the Hutt", Password: "passwd1"}
+	user2 = Client.Must(Client.CreateUser(user2, "")).Data.(*model.User)
+	store.Must(Srv.Store.User().VerifyEmail(user2.Id))
+
+	Client.SetTeamId(th.BasicTeam.Id)
+
+	Client.Login(user2.Email, "passwd1")
+
+	if _, err := Client.GetChannelByName(th.BasicChannel.Name); err == nil {
+		t.Fatal("Should fail due not enough permissions")
+	}
+}

model/client.go

@@ -1252,6 +1252,16 @@ func (c *Client) GetChannels(etag string) (*Result, *AppError) {
 	}
 }
 
+func (c *Client) GetChannelByName(channelName string) (*Result, *AppError) {
+	if r, err := c.DoApiGet(c.GetChannelNameRoute(channelName), "", ""); err != nil {
+		return nil, err
+	} else {
+		defer closeBody(r)
+		return &Result{r.Header.Get(HEADER_REQUEST_ID),
+			r.Header.Get(HEADER_ETAG_SERVER), ChannelMemberFromJson(r.Body)}, nil
+	}
+}
+
 func (c *Client) JoinChannel(id string) (*Result, *AppError) {
 	if r, err := c.DoApiPost(c.GetChannelRoute(id)+"/join", ""); err != nil {
 		return nil, err

webapp/client/client.jsx

@@ -1441,6 +1441,15 @@ export default class Client {
         end(this.handleResponse.bind(this, 'getMyChannelMembers', success, error));
     }
 
+    getChannelByName(channelName, success, error) {
+        request.
+        get(`${this.getChannelsRoute()}/name/${channelName}`).
+        set(this.defaultHeaders).
+        type('application/json').
+        accept('application/json').
+        end(this.handleResponse.bind(this, 'getChannelByName', success, error));
+    }
+
     getChannelStats(channelId, success, error) {
         request.
             get(`${this.getChannelNeededRoute(channelId)}/stats`).

webapp/tests/client_channel.test.jsx

@@ -426,5 +426,20 @@ describe('Client.Channels', function() {
             );
         });
     });
+
+    it('getChannelByName', function(done) {
+        TestHelper.initBasic(() => {
+            TestHelper.basicClient().getChannelByName(
+                TestHelper.basicChannel().name,
+                function(data) {
+                    assert.equal(data.name, TestHelper.basicChannel().name);
+                    done();
+                },
+                function(err) {
+                    done(new Error(err.message));
+                }
+            );
+        });
+    });
 });