Transformations

Transformations can be enabled on queries to transform the query results. ToolJet allows you to transform the query results using two programming languages:

• JavaScript
• Python

警告

• Every transformation is scoped to the query it's written for.
• Actions and CSA(Component Specific Actions) cannot be called within the transformation, they can only be called within RunJS.

Transform using JavaScript

Let's write a simple transformation to compute first_name and last_name for all the customers that we fetch in the previous step.

// write your code here
// return value will be set as data and the original data will be available as rawData
return data.map((row) => {
  return {
    ...row,
    first_name: row.name.split(' ')[0],
    last_name: row.name.split(' ')[1],
  };
});

The query will now look like this:

Transform using Python

Let's use Python transformation to compute first_name and last_name for all the customers that we fetch in the previous step.

return list(map(lambda row: {
  **row,
  'first_name': row['name'].split(' ')[0],
  'last_name': row['name'].split(' ')[1],
}, data))

Example

• Let's take a look at the data returned by a RESTAPI (using mock data here):

  

• Now we will transform the returned data using Python that will append a new key in the returned data called user and that user will have the value from the exposed global variables of ToolJet which is globals.currentUser.email

  return list(map(lambda item: {**item, "user": f"{globals['currentUser']['email']}"}, data))

• Now, you can click on the preview button to check the transformed data.

  

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Click the create button to create the query. Saved queries can be run using the run icon near the query name. Queries run using the run button will behave just as if it was triggered by an app event like button click and thus will alter the state of the app. You can view the query results using the state inspector on the left side-bar of the app builder.

We can see that first_name and last_name are added to all the rows in the data object of the query. If you need the original data of the query, it will be available in the rawData object of the query.

In the next section, we will see how we can display this data using ToolJet's built-in widgets.

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