Data Storage

Some apps need to store and retrieve data. For example apps like Power BI needs to store mapping details of each user. To achieve this we have key - value data storage where the data of the users are stored as a key-value pair and can also be retrieved.

For this tutorial let say we have an object:

const newData = {
    id: 123,
    name: "john doe"
  }

• Store

set can be used to set a key-value pair for every installed user for the app.

app.js:

  await client.db.set("data", newData);

server.js:

  await $Storage.set("data", newData);

• Retrieve:

  get can be used to retrieve a value for that particular installed user. It returns a stringified object which can be then converted to json by JSON.parse(result).

app.js:

  const result = JSON.parse(await window.client.db.get("data"));

server.js:

const result = await $Storage.get("data");

Handling Errors

• 500 error is thrown when you try to fetch a key that is not present in the database.

• Data storage methods directly return an Error object if any error occurs. So, it’s not required to handle the error in the try-catch block.