ui5-typescript-walkthrough

Step 26: Mock Server Configuration

We just ran our app against a real service, but for developing and testing our app we do not want to rely on the availability of the “real” service or put additional load on the system where the data service is located.

This system is the so-called back-end system that we will now simulate with anOpenUI5 feature called mock server. It serves local files, but it simulates a back-end system more realistically than just loading the local data. We will also change the model instantiation part so that the model is configured in the descriptor and instantiated automatically byOpenUI5. This way, we do not need to take care of the model instantiation in the code.

 

Preview

The list of invoices is now served by the Mock Server

You can access the live preview by clicking on this link: 🔗 Live Preview of Step 26.

To download the solution for this step as a zip file, just choose the link here: 📥 Download Solution for Step 26.

Coding

The folder structure of our app project is clearly separating test and productive files after this step. The new test folder now contains a new HTML page mockServer.html which will launch our application in test mode without calling the real service.

The new localService folder contains a metadata.xml service description file for OData, the mockserver.js file that simulates a real service with local data, and the mockdata subfolder that contains the local test data (Invoices.json).

Folder Structure for this Step

webapp/localService/metadata.xml (New)

We create a new folder localService in the App folder and add a new metadata.xml file to it.

The metadata file contains information about the service interface and does not need to be written manually. It can be accessed directly from the “real” service by calling the service URL and adding $metadata at the end (e.g. in our case http://services.odata.org/V2/Northwind/Northwind.svc/$metadata).

For simplicity, we remove all content from the original Northwind OData metadata document that we do not need in our scenario. We also add the status field to the metadata since it is not available in the real Northwind service.

<edmx:Edmx Version="1.0"
	xmlns:edmx="http://schemas.microsoft.com/ado/2007/06/edmx">
	<edmx:DataServices m:DataServiceVersion="1.0" m:MaxDataServiceVersion="3.0"
		xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata">
		<Schema Namespace="NorthwindModel"
			xmlns="http://schemas.microsoft.com/ado/2008/09/edm">
			<EntityType Name="Invoice">
				<Key>
					<PropertyRef Name="ProductName"/>
					<PropertyRef Name="Quantity"/>
					<PropertyRef Name="ShipperName"/>
				</Key>
				<Property Name="ProductName" Type="Edm.String" Nullable="false" MaxLength="40" FixedLength="false" Unicode="true"/>
				<Property Name="Quantity" Type="Edm.Int16" Nullable="false"/>
				<Property Name="ExtendedPrice" Type="Edm.Decimal" Precision="19" Scale="4"/>
				<Property Name="ShipperName" Type="Edm.String" Nullable="false" MaxLength="40" FixedLength="false" Unicode="true"/>
				<Property Name="ShippedDate" Type="Edm.DateTime"/>
				<Property Name="Status" Type="Edm.String" Nullable="false" MaxLength="1" FixedLength="false" Unicode="true"/>
			</EntityType>
		</Schema>
		<Schema Namespace="ODataWebV2.Northwind.Model"
			xmlns="http://schemas.microsoft.com/ado/2008/09/edm">
			<EntityContainer Name="NorthwindEntities" m:IsDefaultEntityContainer="true" p6:LazyLoadingEnabled="true"
				xmlns:p6="http://schemas.microsoft.com/ado/2009/02/edm/annotation">
				<EntitySet Name="Invoices" EntityType="NorthwindModel.Invoice"/>
			</EntityContainer>
		</Schema>
	</edmx:DataServices>
</edmx:Edmx>

webapp/localService/mockdata/Invoices.json (New)

In folder localService we create the new folder mockdata. The mock server determines the local source files with the appriopriate mock data by matching the entity set names defined in the metadata.xml with the local source file names. As we want to simulate data specified in the metadata file in the entity set Invoices, we have to name our mockdata file Invoices.json.

We add the new file Invoices.json to our new folder and define one flat array with the following invoice items:

[
  {
    "ProductName": "Pineapple",
    "Quantity": 21,
    "ExtendedPrice": 87.2,
    "ShipperName": "Fun Inc.",
    "ShippedDate": "/Date(1427839200000)/",
    "Status": "A"
  },
  {
    "ProductName": "Milk",
    "Quantity": 4,
    "ExtendedPrice": 10,
    "ShipperName": "ACME",
    "ShippedDate": "/Date(1424214000000)/",
    "Status": "B"
  },
  {
    "ProductName": "Canned Beans",
    "Quantity": 3,
    "ExtendedPrice": 6.85,
    "ShipperName": "ACME",
    "ShippedDate": "/Date(1425250800000)/",
    "Status": "B"
  },
  {
    "ProductName": "Salad",
    "Quantity": 2,
    "ExtendedPrice": 8.8,
    "ShipperName": "ACME",
    "ShippedDate": "/Date(1428789600000)/",
    "Status": "C"
  },
  {
    "ProductName": "Bread",
    "Quantity": 1,
    "ExtendedPrice": 2.71,
    "ShipperName": "Fun Inc.",
    "ShippedDate": "/Date(1422313200000)/",
    "Status": "A"
  }
]

This file will automatically be found and read by the mock server. ***

webapp/localService/mockserver.ts (New)

Now we can write the code to initialize the mock server which will then simulate any OData request to the real Northwind server. For this we add a new file mockserver.ts to the localService folder.

We import the standard OpenUI5 MockServer module and create a helper object that defines an init method to start the server. The init method creates a MockServer instance with the same URL as the real service calls. The URL in the rootUri configuration parameter has to point to the same URL as defined in the uri property of the data source in the manifest.json descriptor file. In the manifest.json, OpenUI5 automatically interprets a relative URL as being relative to the application namespace. In the TypeScript code, you can ensure this by using the sap.ui.require.toUrl method. The sap/ui/core/util/MockServer then catches every request to the real service and returns a response.

Next, we set two global configuration settings that tell the server to respond automatically and introduce a delay of 500 ms to imitate a typical server response time. Otherwise, we would have to call the respond method on the MockServer manually to simulate the call. The delay can be specified with the URI parameter serverDelay.

To simulate a service, we can simply call the simulate method on the MockServer instance with the path to our newly created metadata.xml. This will read the test data from our local file system and set up the URL patterns that will mimic the real service.

Finally, we call the start method on the MockServer. From this point, each request to the URL pattern rootUri will be processed by the MockServer.

import MockServer from "sap/ui/core/util/MockServer";

export default {
    init: function () {
        // create
        const mockServer = new MockServer({
            rootUri: sap.ui.require.toUrl("ui5/walkthrough/V2/Northwind/Northwind.svc/")
        });

        const urlParams = new URLSearchParams(window.location.search);

        // configure mock server with a delay
        MockServer.config({
            autoRespond: true,
            autoRespondAfter: parseInt(urlParams.get("serverDelay") || "500")
        });

        // simulate
        const path = sap.ui.require.toUrl("ui5/walkthrough/localService");
        mockServer.simulate(path + "/metadata.xml", path + "/mockdata");

        // start
        mockServer.start();
    }
};

webapp/test/initMockServer.ts (New)

As a next step, we create a module that initializes our local mockserver. For this, we add the new test folder to our App folder where we place the new inimockServer.ts file.

First, we call the init method of our local mockserver, then we initialize the app component.

import mockserver from "../localService/mockserver";

// initialize the mock server
mockserver.init();

// initialize the embedded component on the HTML page
import("sap/ui/core/ComponentSupport");

webapp/test/mockServer.html (New)

Finally we create a new mockServer.html page in our test folder. We will use this file to run our app in test mode with our mock server loading mock data loaded from out local Invoices JSON file. Test pages should not be placed in the application root folder but in a subfolder called test to clearly separate productive and test coding.

We copy content of the index.html to it and change the page title to distinguish it from the productive start page. We need to change data-sap-ui-resource-roots property. The namespace now points to the folder above ("../"), because the mockServer.html file is in a subfolder of the webapp folder. Also the bootstrap script to the OpenUI5 core library needs to be adapted this way.

Instead the app component, we define that the initMockServer is initialized from the HTML page.

<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8">
	<title>UI5 TypeScript Walkthrough - Mockserver Test Page</title>
	<script
		id="sap-ui-bootstrap"
		src="../resources/sap-ui-core.js"
		data-sap-ui-theme="sap_horizon"
		data-sap-ui-compat-version="edge"
		data-sap-ui-async="true"
		data-sap-ui-on-init="module:ui5/walkthrough/test/initMockServer"
		data-sap-ui-resource-roots='{
			"ui5.walkthrough": "../"
		}'>

	</script>
</head>
<body class="sapUiBody" id="content">
	<div data-sap-ui-component data-name="ui5.walkthrough" data-id="container" data-settings='{"id" : "walkthrough"}'></div>
</body>
</html>

When launching the app with the mockServer.html file the initMockServer is called, that first initializes our local mock server and only then our app component. This way we catch all requests that would go to the “real” service and process them locally by our mock server instead. The component itself does not “know” that it now runs in test mode.

If you switch from the index.html file to the mockServer.html file in the browser, you can now see that the test data is displayed from the local sources, but with a short delay as defined in our local mock server configuration.

This approach is perfect for local testing, even without any network connection. This way your development does not depend on the availability of a remote server, i.e. to run your tests.

From this point on, we have two different entry pages: One for the real “connected” app (index.html) and one for local testing (test/mockServer.html). You can freely decide if you want to do the next steps on the real service data or on the local data within the app. Try calling the app with the index.html file and the mockServer.html file to see the difference. If the real service connection cannot be made, for example when there is no network connection, you can always fall back to the local test page.

UI5 Tooling

package.json (optional)

In case you prefer to continue with the local data, you should adjust the start script in the package.json to open mockServer.html instead of index.html:

{
  "name": "ui5.walkthrough",
  "version": "1.0.0",
  "description": "OpenUI5 TypeScript Walkthrough",
  "private": true,
  "scripts": {
    "start": "ui5 serve -o test/mockServer.html"
  },
  "devDependencies": {
    "@types/openui5": "^1.120.0",
    "@ui5/cli": "^3.7.1",
    "typescript": "^5.2.2",	  
    "ui5-middleware-livereload": "^3.0.2",
    "ui5-middleware-serveframework": "^3.0.0",
    "ui5-middleware-simpleproxy": "^3.2.8",
    "ui5-tooling-transpile": "^3.2.7"
  }
}

Conventions

 

Next: Step 27: Remote OData Service

Previous: Step 25: Unit Test with QUnit

Related Information

Mock Server

API Reference: sap.ui.core.util.MockServer

Create a Northwind Destination

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