Extend Google Sheets with Harvest Data

Interact with Harvest data from Google Sheets through macros, custom functions, and add-ons. The CData API Server enables connectivity to Harvest data from cloud-based and mobile applications like Google Sheets. The API Server is a lightweight Web application that produces OData services for Harvest.

Google Apps Script can consume these OData services in the JSON format. This article shows how to create a simple add-on that populates a Google Spreadsheet with Invoices data.

Set Up the API Server

If you have not already done so, download the CData API Server. Once you have installed the API Server, follow the steps below to begin producing secure Harvest OData services:

Connect to Harvest

To work with Harvest data from Google Sheets, we start by creating and configuring a Harvest connection. Follow the steps below to configure the API Server to connect to Harvest data:

1. First, navigate to the Connections page.
2. Click Add Connection and then search for and select the Harvest connection. 👁 Selecting a data source (SQLite is shown)
   
3. Enter the necessary authentication properties to connect to Harvest.

   Start by setting the Profile connection property to the location of the Harvest Profile on disk (e.g. C:\profiles\Harvest.apip). Next, set the ProfileSettings connection property to the connection string for Harvest (see below).

   Harvest API Profile Settings

   To authenticate to Harvest, you can use either Token authentication or the OAuth standard. Use Basic authentication to connect to your own data. Use OAuth to allow other users to connect to their data.

   Using Token Authentication

   To use Token Authentication, set the APIKey to your Harvest Personal Access Token in the ProfileSettings connection property. In addition to APIKey, set your AccountId in ProfileSettings to connect.

   Using OAuth Authentication

   First, register an OAuth2 application with Harvest. The application can be created from the "Developers" section of Harvest ID.

   After setting the following connection properties, you are ready to connect:

   • ProfileSettings: Set your AccountId in ProfileSettings.
   • AuthScheme: Set this to OAuth.
   • OAuthClientId: Set this to the client ID that you specified in your app settings.
   • OAuthClientSecret: Set this to the client secret that you specified in your app settings.
   • CallbackURL: Set this to the Redirect URI that you specified in your app settings.
   • InitiateOAuth: Set this to GETANDREFRESH. You can use InitiateOAuth to manage how the driver obtains and refreshes the OAuthAccessToken.
   👁 Connecting to a datasource (SQLite is shown)
   
4. After configuring the connection, click Save & Test to confirm a successful connection.

Configure API Server Users

Next, create a user to access your Harvest data through the API Server. You can add and configure users on the Users page. Follow the steps below to configure and create a user:

1. On the Users page, click Add User to open the Add User dialog.
2. Next, set the Role, Username, and Privileges properties and then click Add User. 👁 Configure a new user
   
3. An Authtoken is then generated for the user. You can find the Authtoken and other information for each user on the Users page: 👁 API Server user settings
   

Creating API Endpoints for Harvest

Having created a user, you are ready to create API endpoints for the Harvest tables:

1. First, navigate to the API page and then click Add Table . 👁 Add tables
   
2. Select the connection you wish to access and click Next. 👁 Select the connection (SQLite is shown)
   
3. With the connection selected, create endpoints by selecting each table and then clicking Confirm. 👁 Adding tables from the connection (SQLite is shown)
   

Gather the OData Url

Having configured a connection to Harvest data, created a user, and added resources to the API Server, you now have an easily accessible REST API based on the OData protocol for those resources. From the API page in API Server, you can view and copy the API Endpoints for the API:

Retrieve Harvest Data

Open the Script Editor from your spreadsheet by clicking Tools -> Script Editor. In the Script Editor, add the following function to populate a spreadsheet with the results of an OData query:

function retrieve(){
 var url = "https://MyUrl/api.rsc/Invoices?select=Id,Id,ClientName,State";
 var response = UrlFetchApp.fetch(url,{
 headers: {"Authorization": "Basic " + Utilities.base64Encode("MyUser:MyAuthtoken")}
 }); 
 var json = response.getContentText();
 var sheet = SpreadsheetApp.getActiveSheet();
 var a1 = sheet.getRange('a1');
 var index=1;
 var invoices = JSON.parse(json).value;

 var cols = [["Id","Id","ClientName","State"]]; 
 sheet.getRange(1,1,1,4).setValues(cols);

 row=2;
 for(var i in invoices){
 for (var j in invoices[i]) {
 switch (j) {
 case "Id":
 a1.offset(row,0).setValue(account[i][j]);
 break;
 case "Id":
 a1.offset(row,1).setValue(account[i][j]);
 break;
 case "ClientName":
 a1.offset(row,2).setValue(account[i][j]);
 break;
 case "State":
 a1.offset(row,3).setValue(account[i][j]);
 break;
 } 
 }
 row++;
 }
}

Follow the steps below to add an installable trigger to populate the spreadsheet when opened:

1. Click Resources -> Current Project's Triggers -> Add a New Trigger.
2. Select retrieve in the Run menu.
3. Select From Spreadsheet.
4. Select On open.

After closing the dialog, you are prompted to allow access to the application.

You can test the script by clicking Publish -> Test as Add-On. Select the version, installation type, and spreadsheet to create a test configuration. You can then select and run the test configuration.