feat: add EntryPage for login, signup pages to fix background flashing issue (#1416)

* feat: fix flush in login Pages

* fix: code format

* fix: improve code

* Update App.js

* Update EntryPage.js

* fix: optimize api request

* Update App.js

* Update App.js

* fix: fix css

* fix: css and getApllicationObj

Co-authored-by: hsluoyz <hsluoyz@qq.com>

web/src/EntryPage.js

@@ -0,0 +1,84 @@
+// Copyright 2022 The Casdoor Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import React from "react";
+import {Redirect, Route, Switch} from "react-router-dom";
+import {Spin} from "antd";
+import i18next from "i18next";
+import * as Setting from "./Setting";
+import SignupPage from "./auth/SignupPage";
+import SelfLoginPage from "./auth/SelfLoginPage";
+import LoginPage from "./auth/LoginPage";
+import SelfForgetPage from "./auth/SelfForgetPage";
+import ForgetPage from "./auth/ForgetPage";
+import PromptPage from "./auth/PromptPage";
+import CasLogout from "./auth/CasLogout";
+
+class EntryPage extends React.Component {
+  constructor(props) {
+    super(props);
+    this.state = {
+      application: undefined,
+    };
+  }
+
+  renderHomeIfLoggedIn(component) {
+    if (this.props.account !== null && this.props.account !== undefined) {
+      return <Redirect to="/" />;
+    } else {
+      return component;
+    }
+  }
+
+  renderLoginIfNotLoggedIn(component) {
+    if (this.props.account === null) {
+      sessionStorage.setItem("from", window.location.pathname);
+      return <Redirect to="/login" />;
+    } else if (this.props.account === undefined) {
+      return null;
+    } else {
+      return component;
+    }
+  }
+
+  render() {
+    const onUpdateApplication = (application) => {
+      this.setState({
+        application: application,
+      });
+    };
+
+    return <div className="loginBackground" style={{backgroundImage: Setting.inIframe() || Setting.isMobile() ? null : `url(${this.state.application?.formBackgroundUrl})`}}>
+      <Spin spinning={this.state.application === undefined} tip={i18next.t("login:Loading")} style={{margin: "0 auto"}} />
+      <Switch>
+        <Route exact path="/signup" render={(props) => this.renderHomeIfLoggedIn(<SignupPage {...this.props} application={this.state.application} onUpdateApplication={onUpdateApplication} {...props} />)} />
+        <Route exact path="/signup/:applicationName" render={(props) => this.renderHomeIfLoggedIn(<SignupPage {...this.props} application={this.state.application} onUpdateApplication={onUpdateApplication} {...props} />)} />
+        <Route exact path="/login" render={(props) => this.renderHomeIfLoggedIn(<SelfLoginPage {...this.props} application={this.state.application} onUpdateApplication={onUpdateApplication} {...props} />)} />
+        <Route exact path="/login/:owner" render={(props) => this.renderHomeIfLoggedIn(<SelfLoginPage {...this.props} application={this.state.application} onUpdateApplication={onUpdateApplication} {...props} />)} />
+        <Route exact path="/auto-signup/oauth/authorize" render={(props) => <LoginPage {...this.props} application={this.state.application} type={"code"} mode={"signup"} onUpdateApplication={onUpdateApplication}{...props} />} />
+        <Route exact path="/signup/oauth/authorize" render={(props) => <SignupPage {...this.props} application={this.state.application} onUpdateApplication={onUpdateApplication} {...props} />} />
+        <Route exact path="/login/oauth/authorize" render={(props) => <LoginPage {...this.props} application={this.state.application} type={"code"} mode={"signin"} onUpdateApplication={onUpdateApplication} {...props} />} />
+        <Route exact path="/login/saml/authorize/:owner/:applicationName" render={(props) => <LoginPage {...this.props} application={this.state.application} type={"saml"} mode={"signin"} onUpdateApplication={onUpdateApplication} {...props} />} />
+        <Route exact path="/forget" render={(props) => this.renderHomeIfLoggedIn(<SelfForgetPage {...this.props} application={this.state.application} onUpdateApplication={onUpdateApplication} {...props} />)} />
+        <Route exact path="/forget/:applicationName" render={(props) => this.renderHomeIfLoggedIn(<ForgetPage {...this.props} application={this.state.application} onUpdateApplication={onUpdateApplication} {...props} />)} />
+        <Route exact path="/prompt" render={(props) => this.renderLoginIfNotLoggedIn(<PromptPage {...this.props} application={this.state.application} onUpdateApplication={onUpdateApplication} {...props} />)} />
+        <Route exact path="/prompt/:applicationName" render={(props) => this.renderLoginIfNotLoggedIn(<PromptPage {...this.props} application={this.state.application} onUpdateApplication={onUpdateApplication} {...props} />)} />
+        <Route exact path="/cas/:owner/:casApplicationName/logout" render={(props) => this.renderHomeIfLoggedIn(<CasLogout {...this.props} application={this.state.application} {...props} />)} />
+        <Route exact path="/cas/:owner/:casApplicationName/login" render={(props) => {return (<LoginPage {...this.props} application={this.state.application} type={"cas"} mode={"signup"} {...props} />);}} />
+      </Switch>
+    </div>;
+  }
+}
+
+export default EntryPage;