Add navigation to your External API call (Slack)

You need to create a new view that you will be able to navigate to in your Slack application. To create a new view and controller, right-click on the webapp folder and select New > SAPUI5 View.

On the New SAPUI5 View page, leave the initial details and add a View Name. In this example, you can call it Detail. Click Next.

On the Confirmation page, click Finish.

Open your new Detail view by opening the folders webapp > view and selecting the Detail.view.xml file.

You will add a basic Object Header to your detail view to display some more details about the selected message. Add the following code in-between the <content> tags in Detail view.

<ObjectHeader
  responsive="true"
  fullScreenOptimized="true"
  intro="Timestamp"
  title="Message">
  <attributes>
    <ObjectAttribute text="Author" />
    <ObjectAttribute text="Message Type" />
  </attributes>
</ObjectHeader>

Finally, remove the the <App> and the lowercase <pages> tags from the Detail view.

SAVE your changes.

In the webapp folder, open the manifest.json file.

In the sap.ui5 array, you need to define a new routing parameter, where you will define the configurations, routes, and targets for routing or navigation in the application.

"routing": {
  "config": {
    "routerClass": "sap.m.routing.Router",
    "viewType": "XML",
    "viewPath": "slack_app.view",
    "controlId": "app",
    "controlAggregation": "pages"
  },
  "routes": [{
    "pattern": "",
    "name": "view1",
    "target": "view1"
  }, {
    "pattern": "detail/{messagePath}",
    "name": "detail",
    "target": "detail"
  }],
  "targets": {
    "view1": {
      "viewName": "View1"
    },
    "detail": {
      "viewName": "Detail"
    }
  }
},

This will define what the relationship between the View1 view and the Detail view will be. Based on the pattern specified in the routes array, the application will use the URL to determine if it is looking at the Detail view or the View1 view.

SAVE your changes.

Open the View1.view.xml file in the webapp > view folder. The controlId set in the Manifest files means that you need to add an ID to the <App> tag in your main view, which is View1. In the <App> tag, add the id="app" attribute.

<App id="app">

SAVE your changes.

In the webapp folder, open theComponent.js file.

You need to initialize the router for the application. Add this line of code to the init function in the Component.js file.

			this.getRouter().initialize();

SAVE your changes.

In the webapp > view folder, open theView1.view.xml file.

You need to enable navigation in the table. Replace the <ColumnListItem> in the <Table> with the below code. This sets the type attribute to Navigation and the press attribute to a function you will define in the controller to handle the navigation.

<ColumnListItem
  type="Navigation"
  press="onPress">

SAVE your changes.

In the webapp > controller folder, open theView1.controller.js file.

Add the new onPress function that will handle your navigation. This function has one parameter called oEvent. You want to get the source of the oEvent where you will be able to find data about the specific message clicked. You need to get the router initialized in the Component.js file by access the core of the application. And finally, you will use the navTo function and bind message data to the messagePath binding defined in the manifest.json file.

onPress: function (oEvent) {
  var oItem = oEvent.getSource();
  var oRouter = sap.ui.core.UIComponent.getRouterFor(this);
  oRouter.navTo("detail", {
    messagePath: encodeURIComponent(oItem.getBindingContext("messages").getPath().substr(1))
  });
},

SAVE your changes.

In the webapp > controller folder, open theDetail.controller.js file.

First, you need to add some new resources to the controller. This controller will need access to the browser history, so add the routing history resource. Also, you will need access to JSONModel in this controller. Add these resources to the define array.

,
	"sap/ui/core/routing/History",
	"sap/ui/model/json/JSONModel"

To make the resources available in the controller, add the following parameters to the controller function definition.

, History, JSONModel

Delete all the commented code in the controller. You will define a new set of functions.

Create a new onInit (#1) function. This function needs to create a new JSONModel to hold the message details, and the model needs to be bound to the view. Additionally, you need to get the router for this view and use it to match the data passed in the messagePath argument.

onInit: function () {
  var oModel = new JSONModel();
  this.getView().setModel(oModel, "message");

  var oRouter = sap.ui.core.UIComponent.getRouterFor(this);
  oRouter.getRoute("detail").attachMatched(this._onRouteMatched, this);
},

Add a _onRouteMatched (#2) function that is called from the onInit function. The _onRouteMatched function has a parameter of oEvent. This function will bind the data for the message based on the argument messagePath from the main view. It will bind it to the message model you created in the onInit function.

_onRouteMatched: function (oEvent) {
  this.getView().bindElement({
    path: "/" + oEvent.getParameter("arguments").messagePath,
    model: "message"
  });
},

Finally, add in a onNavBack (#3) function that will allow you to navigate back to the main view (View1) from the Detail view. The back navigation uses the browser history to go back to the page you were previous on. If the browser history cannot be accessed, you will be navigated back to the View1 view without any of the history of the previous page.

onNavBack: function () {
  var oHistory = History.getInstance();
  var sPreviousHash = oHistory.getPreviousHash();

  if (sPreviousHash !== undefined) {
    window.history.go(-1);
  } else {
    var oRouter = sap.ui.core.UIComponent.getRouterFor(this);
    oRouter.navTo("view1", true);
  }
}

SAVE your changes.

In the webapp > view folder, open theDetail.view.xml file.

You need to update the <Page> attributes to allow for backwards navigation. Rename the page to title="Details". Add 2 new properties for adding the navigation button. Adding the showNavButton property and setting it to true allows for the back arrow to appear in the header. Adding the navButtonPress attributes defines the function to use in the controller to complete the navigation action. Your navigation function is defines as onNavBack.

<Page title="Details"
  showNavButton="true"
  navButtonPress="onNavBack">

Make sure all your changes are saved and RUN your application.