Real time clock in Google sheets - google-sheets

Question

Is there any way to output real time clock values in google sheets? Basically what I'm trying to do is use the values in a cell to create a live Gantt chart that will output the status of the machine based on the time value and the downtime reason the operator used.

Answer 1

There are 2 ways of achieving this. The first is the simplest, =now() gets updated every minute automatically. The second technique is more complex but offers more control, especially if you want to control the precise moment when the clock should get updated.
Easiest way - 20 seconds:
Apply the =NOW() function and change your recalculation setting to "On change and every minute" in your spreadsheet at File > Spreadsheet settings.
Long way - 5 to 30 minutes. Requires a server to execute code every x minutes
Its possible to do this via the API. There are a couple of ways to achieve this, but both involve the API.
1) Create a blank sheet and update the time in any cell using the API. Lets call this sheet universal. Simply inserting "=now()" into a cell will always ensure the time is updated every time an API call is made. Overwrite this cell with "=now()" in every API call. Then use the function : IMPORTRANGE() in any sheet referencing the call value in the universal sheet. This is the preferred option since you only need to create code for one sheet and then you can reference in any other sheet.
2) Same as above, but just write directly to your sheet and cell as opposed to a universal sheet. The disadvantage of this method is if you move cells around you will need to change your code.
Both options will require you to call the API and setting up a scheduled job to run the program every x minutes.
Instructions (JAVA - though you can follow the same logic for other languages). Pretty much most of the below is copied from Google Sheets API guide, I have listed all my steps below:
Step 1: Turn on the Google Sheets API
a Use this wizard to create or select a project in the Google Developers Console and automatically turn on the API. Click Continue, then Go to credentials.
b On the Add credentials to your project page, click the Cancel button.
c At the top of the page, select the OAuth consent screen tab. Select an Email address, enter a Product name if not already set, and click the Save button.
d Select the Credentials tab, click the Create credentials button and select OAuth client ID.
e Select the application type Other, enter the name "Google Sheets API Quickstart", and click the Create button.
f Click OK to dismiss the resulting dialog.
g Click the file_download (Download JSON) button to the right of the client ID.
h Move this file to your working directory and rename it client_secret.json.
Step 2 If using Maven add the following dependencies to your pom file:
<dependency>
<groupId>com.google.api-client</groupId>
<artifactId>google-api-client-java6</artifactId>
<version>1.23.0</version>
</dependency>
<dependency>
<groupId>com.google.oauth-client</groupId>
<artifactId>google-oauth-client-jetty</artifactId>
<version>1.23.0</version>
</dependency>
<dependency>
<groupId>com.google.apis</groupId>
<artifactId>google-api-services-sheets</artifactId>
<version>v4-rev504-1.23.0</version>
</dependency>
Step 3 Copy this class Credentials.java
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.List;
import com.google.api.client.auth.oauth2.Credential;
import com.google.api.client.extensions.java6.auth.oauth2.AuthorizationCodeInstalledApp;
import com.google.api.client.extensions.jetty.auth.oauth2.LocalServerReceiver;
import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeFlow;
import com.google.api.client.googleapis.auth.oauth2.GoogleClientSecrets;
import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.json.JsonFactory;
import com.google.api.client.json.jackson2.JacksonFactory;
import com.google.api.client.util.store.FileDataStoreFactory;
import com.google.api.services.sheets.v4.Sheets;
import com.google.api.services.sheets.v4.SheetsScopes;
public class Credentials {
/** Application name. */
private static final String APPLICATION_NAME =
"Google Sheets";
/** Directory to store user credentials for this application. */
private static final java.io.File DATA_STORE_DIR = new java.io.File(
System.getProperty("user.home"), ".credentials/sheets.googleapis.com-java-quickstart");
/** Global instance of the {#link FileDataStoreFactory}. */
private static FileDataStoreFactory DATA_STORE_FACTORY;
/** Global instance of the JSON factory. */
private static final JsonFactory JSON_FACTORY =
JacksonFactory.getDefaultInstance();
/** Global instance of the HTTP transport. */
private static HttpTransport HTTP_TRANSPORT;
/** Global instance of the scopes required by this quickstart.
*
* If modifying these scopes, delete your previously saved credentials
* at ~/.credentials/sheets.googleapis.com-java-quickstart
*/
private static final List<String> SCOPES =
Arrays.asList(SheetsScopes.SPREADSHEETS);
static {
try {
HTTP_TRANSPORT = GoogleNetHttpTransport.newTrustedTransport();
DATA_STORE_FACTORY = new FileDataStoreFactory(DATA_STORE_DIR);
} catch (Throwable t) {
t.printStackTrace();
System.exit(1);
}
}
/**
* Creates an authorized Credential object.
* #return an authorized Credential object.
* #throws IOException
*/
public static Credential authorize() throws IOException {
// Load client secrets.
InputStream in =
Quickstart.class.getResourceAsStream("/client_secret.json");
GoogleClientSecrets clientSecrets =
GoogleClientSecrets.load(JSON_FACTORY, new InputStreamReader(in));
// Build flow and trigger user authorization request.
GoogleAuthorizationCodeFlow flow =
new GoogleAuthorizationCodeFlow.Builder(
HTTP_TRANSPORT, JSON_FACTORY, clientSecrets, SCOPES)
.setDataStoreFactory(DATA_STORE_FACTORY)
.setAccessType("offline")
.build();
Credential credential = new AuthorizationCodeInstalledApp(
flow, new LocalServerReceiver()).authorize("user");
System.out.println(
"Credentials saved to " + DATA_STORE_DIR.getAbsolutePath());
return credential;
}
/**
* Build and return an authorized Sheets API client service.
* #return an authorized Sheets API client service
* #throws IOException
*/
public static Sheets getSheetsService() throws IOException {
Credential credential = authorize();
return new Sheets.Builder(HTTP_TRANSPORT, JSON_FACTORY, credential)
.setApplicationName(APPLICATION_NAME)
.build();
}
}
Step 4 Copy the class UpdateDate.java below. Change the spreadsheetID with the ID of your spreadsheet. Change the range with your cell ref. I have entered a default value of Sheet1!a1 as an example
import java.io.IOException;
import java.util.Arrays;
import java.util.List;
import com.google.api.services.sheets.v4.Sheets;
import com.google.api.services.sheets.v4.model.UpdateValuesResponse;
import com.google.api.services.sheets.v4.model.ValueRange;
public class UpdateDate {
public static void main(String[] args) throws IOException{
Sheets service = Credentials.getSheetsService();
String spreadsheetId = "YOUR_SHEET_ID";
String range = "Sheet1!a1";
#SuppressWarnings("unchecked")
List<List<Object>> values = Arrays.asList(
Arrays.asList(
(Object)"=NOW()"
)
);
ValueRange body = new ValueRange().setValues(values);
UpdateValuesResponse result =
service.spreadsheets().values().update(spreadsheetId, range, body)
.setValueInputOption("USER_ENTERED")
.execute();
}
}
Step 5 Setup a scheduled job to run every x minutes according to your use case. The very first time you run this your browser should open and you will need to click on the accept consent screen. Credentials are then saved locally so thereafter you can run the process via command line without having to click on the consent screen again.
Good Luck!

Answer 2

It looks like you want the NOW function. I don't think sheets supports real time updates, so a volatile function (changes when the sheet is updated) is the best you can do.