Set a default value

Default values can be set for any column and will be set whenever a new row is added. You can set default values in Column settings.

Video demo

Undefined

By default, the field’s value is undefined. This value is ignored by Firestore, so the field won’t be set at all in the database.

Null

Setting the default value as null makes it possible to filter rows by empty fields.

Static

Setting a static value will make all new rows have the same value for this field by default.

Dynamic

Setting a dynamic value lets you use JavaScript code to generate a default field value.

example:

When user creates an account user document would be created. the document would need a default currency based on the user's country . if you have countries collection with all the settings available you can do the following:

const defaultValueFn: DefaultValue = ({ row, db }) => {
  logging.log("dynamicValueFn started");
  // set default currency of user's account
  const countryDoc = await db.collection("countries").doc(row.country).get();
  const currency = countryDoc.get("currency");
  return currency;
};

export default defaultValue;

Alternatively you can get the information form an external api to set the default value

const defaultValueFn: DefaultValue = ({ row, db }) => {
  logging.log("dynamicValueFn started");
  // set default currency of user's account
  const resp = await fetch(
    `https://restcountries.com/v3.1/name/${row.country}`
  );
  const respData = await resp.json();
  // get the currency code from the response
  const currencyCode = Object.keys(respData[0].currencies)[0];
  const currency = respData[0].currencies[currencyCode];
  return {
    code: currencyCode,
    name: currency.name,
    symbol: currency.symbol,
  };
};

export default defaultValue;

API

Your code has access to the following parameters and can use the await keyword.

You can also use npm packages using CommonJS require imports.

Name	Type	Description
row	Record<string, any>	All data in the current row.
ref	DocumentReference	Reference to the corresponding Firestore document of the current row.
db	Firestore	Access to the full Cloud Firestore instance to access any collection or document.
auth	Auth	Access to Firebase Auth via Admin SDK
storage	Storage	Access to Firebase Storage via Admin SDK
rowy	Rowy	Access to cloud function metadata secret Manager and storage utilities

Examples

Example: Parent document

Use the row ref to get a value from the parent document.

const defaultValueFn: DefaultValue = async ({ ref }) => {
  logging.log("dynamicValueFn started");
  const parentDoc = await ref.parent.parent.get();
  return parentDoc.get("FIELD_KEY_HERE");
};

export default defaultValue;

Example: Any document

Use db to get any document in your database.

const defaultValueFn: DefaultValue = async ({ row, db }) => {
  logging.log("dynamicValueFn started");
  const query = await db
    .collection("someCollection")
    .where("aField", "==", row.someKey)
    .get();
  return query.docs[0].get("keyName");
};

export default defaultValue;

Example: npm package

Use an npm package to generate a UUID.

const defaultValueFn: DefaultValue = ({ row, db }) => {
  logging.log("dynamicValueFn started");
  const { v4: uuidv4 } = require("uuid");
  return uuidv4();
};

export default defaultValue;

Example: reference Data

Store document id in the document, for easy queries

const defaultValueFn: DefaultValue = ({ ref }) => {
  logging.log("dynamicValueFn started");
  return ref.id;
};

export default defaultValue;