`routeAction$()`

Actions allows to handle form submissions, allowing to perform side effects such as writing to a database, or sending an email.

Actions can also return data back to the client/browser, allowing to update the UI accordingly, i.e. showing a success message after a form submission.

Actions can be declared using the routeAction$() or globalAction$() exported from @builder.io/qwik-city.

src/routes/layout.tsx

import { component$ } from '@builder.io/qwik';
import { routeAction$, Form } from '@builder.io/qwik-city';
 
export const useAddUser = routeAction$(async (data, requestEvent) => {
  // This will only run on the server when the user submits the form (or when the action is called programmatically)
  const userID = await db.users.add({
    firstName: data.firstName,
    lastName: data.lastName,
  });
  return {
    success: true,
    userID,
  };
});
 
export default component$(() => {
  const action = useAddUser();
 
  return (
    <>
      <Form action={action}>
        <input name="firstName" />
        <input name="lastName" />
        <button type="submit">Add user</button>
      </Form>
      {action.value?.success && (
        // When the action is done successfully, the `action.value` property will contain the return value of the action
        <p>User {action.value.userID} added successfully</p>
      )}
    </>
  );
});

Since actions are not executed during rendering, they can have side effects such as writing to a database, or sending an email. An action only runs when called explicitly.

Using actions with `<Form/>`

The best way to call an action is using the <Form/> component exported in @builder.io/qwik-city.

src/routes/index.tsx

import { component$ } from '@builder.io/qwik';
import { routeAction$, Form } from '@builder.io/qwik-city';
 
export const useAddUser = routeAction$(async (user) => {
  const userID = await db.users.add(user);
  return {
    success: true,
    userID,
  };
});
 
export default component$(() => {
  const action = useAddUser();
  return (
    <Form action={action}>
      <input name="name" />
      <button type="submit">Add user</button>
      {action.value?.success && <p>User added successfully</p>}
    </Form>
  );
});

Under the hood, the <Form/> component uses a native HTML <form> element, so it will work without JavaScript.

When JS is enabled, the <Form/> component will intercept the form submission and trigger the action in SPA mode, allowing to have a full SPA experience.

Using actions programmatically

Actions can also be triggered programmatically using the action.submit() method, i.e. you don't need a <Form/> component, but you can trigger the action from a button click or any other event, just like you would do with a function.

src/routes/index.tsx

import { component$ } from '@builder.io/qwik';
import { routeAction$ } from '@builder.io/qwik-city';
 
export const useAddUser = routeAction$(async (user) => {
  const userID = await db.users.add(user);
  return {
    success: true,
    userID,
  };
});
 
export default component$(() => {
  const action = useAddUser();
  return (
    <section>
      <button
        onClick$={async () => {
          const { value } = await action.submit({ name: 'John' });
          console.log(value);
        }}
      >
        Add user
      </button>
      {action.value?.success && <p>User added successfully</p>}
    </section>
  );
});

In the example above, the addUser action is triggered when the user clicks the button. The action.submit() method returns a Promise that resolves when the action is done.

Actions with Event Handlers

We can use the onSubmitCompleted$ event handler after an action is executed successfully and returns some data. It is particularly useful when you need to perform additional tasks, such as resetting UI elements or updating the application state, once an action has been completed successfully.

Here's an example of the onSubmitCompleted$ handler used to edit an item in a EditForm component of a todo app.

src/components/EditForm.tsx

import { component$, type Signal, useSignal } from '@builder.io/qwik';
import { Form } from '@builder.io/qwik-city';
import { type ListItem, useEditFromListAction } from '../../routes/index';
 
export interface EditFormProps {
  item: listItem;
  editingIdSignal: Signal<string>;
}
 
const EditForm = component$(
  ({ item, editingIdSignal }: EditFormProps) => {
    const editAction = useEditFromListAction();
 
    return (
      <div>
        <Form
          action={editAction}
          onSubmitCompleted$={() => {
            editingIdSignal.value = '';
          }}
          spaReset
        >
          <input
            type="text"
            value={item.text}
            name="text"
            id={`edit-${item.id}`}
          />
          {/* Sends item.id with form data on submission. */}
          <input type="hidden" name="id" value={item.id} />
          <button type="submit">
            Submit
          </button>
        </Form>
 
        <div>
          <button onClick$={() => (editingIdSignal.value = '')}>
            Cancel
          </button>
        </div>
      </div>
    );
  }
);
 
export default EditForm;

In this example, onSubmitCompleted$ is used to reset the editingIdSignal value to an empty string once the form submission is completed successfully. This allows the application to update its state and return to the default view.

Validation and type safety

Qwik comes with built-in support for Zod, a TypeScript-first schema validation that can be used directly with actions, using the zod$() function.

Actions + Zod allows to create type safe forms, where the data is validated server side before the action is executed.

src/routes/index.tsx

import { component$ } from '@builder.io/qwik';
import { routeAction$, zod$, z, Form } from '@builder.io/qwik-city';
 
export const useAddUser = routeAction$(
  async (user) => {
    // The "user" is strongly typed: { firstName: string, lastName: string }
    const userID = await db.users.add({
      firstName: user.firstName,
      lastName: user.lastName,
    });
    return {
      success: true,
      userID,
    };
  },
  // Zod schema is used to validate that the FormData includes "firstName" and "lastName"
  zod$({
    firstName: z.string(),
    lastName: z.string(),
  })
);
 
export default component$(() => {
  const action = useAddUser();
  return (
    <>
      <Form action={action}>
        <input name="firstName" />
        <input name="lastName" />
 
        {action.value?.failed && <p>{action.value.fieldErrors?.firstName}</p>}
        <button type="submit">Add user</button>
      </Form>
      {action.value?.success && (
        <p>User {action.value.userID} added successfully</p>
      )}
    </>
  );
});

When submitting data to a routeAction(), the data is validated against the Zod schema. If the data is invalid, the action will put the validation error in the routeAction.value property.

Please refer to the Zod documentation for more information on how to use Zod schemas.

HTTP request and response

routeAction$ and globalAction$ have access to the RequestEvent object which includes information about the current HTTP request and response.

This allows actions to access the request headers, cookies, url and environment variables within the routeAction$ function.

src/routes/product/[user]/index.tsx

import { routeAction$ } from '@builder.io/qwik-city';
 
// The second argument of the action is the `RequestEvent` object
export const useProductRecommendations = routeAction$(
  async (_data, requestEvent) => {
    console.log('Request headers:', requestEvent.request.headers);
    console.log('Request cookies:', requestEvent.cookie);
    console.log('Request url:', requestEvent.url);
    console.log('Request params:', requestEvent.params);
    console.log('MY_ENV_VAR:', requestEvent.env.get('MY_ENV_VAR'));
  }
);

Action Failures

In order to return non-success values, the action must use the fail() method.

import { routeAction$, zod$, z } from '@builder.io/qwik-city';
 
export const useAddUser = routeAction$(
  async (user, { fail }) => {
    // `user` is typed { name: string }
    const userID = await db.users.add(user);
    if (!userID) {
      return fail(500, {
        message: 'User could not be added',
      });
    }
    return {
      userID,
    };
  },
  zod$({
    name: z.string(),
  })
);

Failures are stored in the action.value property, just like the success value. However, the action.value.failed property is set to true when the action fails. Futhermore, failure messages can be found in the fieldErrors object according to properties defined in your Zod schema.

import { component$ } from '@builder.io/qwik';
import { Form } from '@builder.io/qwik-city';
 
export default component$(() => {
  const action = useAddUser();
  return (
    <Form action={action}>
      <input name="name" />
      <button type="submit">Add user</button>
      {action.value?.failed && <p>{action.value.fieldErrors.name}</p>}
      {action.value?.userID && <p>User added successfully</p>}
    </Form>
  );
});

Thanks to Typescript type discrimination, you can use the action.value.failed property to discriminate between success and failure.

Previous form state

When an action is triggered, the previous state is stored in the action.formData property. This is useful to display a loading state while the action is running.

import { component$ } from '@builder.io/qwik';
import { routeAction$, Form, zod$, z } from '@builder.io/qwik-city';
 
export const useAddUser = routeAction$(async (user) => {
  // handle action...
});
 
export default component$(() => {
  const action = useAddUser();
  return (
    <Form action={action}>
      <input name="name" value={action.formData?.get('name')} />
      <button type="submit">Add user</button>
    </Form>
  );
});

The action.formData is specially useful as it allows to keep the form data filled by the user even on a page refresh, allowing to have a full SPA experience, even with JS disabled.

Route vs Global actions

Actions can be declared using the routeAction$() or globalAction$() exported from @builder.io/qwik-city, the only difference between the two is that routeAction$() is scoped to a route, while globalAction$() is globally available across the whole app.

We recommend starting with routeAction$() and only use globalAction$() when you need to share an action across multiple routes, or if you wish to use the action in a component that is not a route.

`routeAction$()`

routeAction$() can only be declared inside the src/routes folder, in a layout.tsx or index.tsx file, and they MUST be exported, just like a routeLoader$(). Since routeAction$() are only accessible within the route it's declared, they are recommended when the action needs to access some user data, or it's a protected route. Think about it like a "private" action.

src/routes/form/index.tsx

import { routeAction$ } from '@builder.io/qwik-city';
 
export const useChangePassword = routeAction$((data) => {
  // ...
});

`globalAction$()`

globalAction$() can be declared anywhere in the src folder. Since globalAction$() are globally available, they are recommended when the action needs to be shared across multiple routes, or when the action doesn't need to access any user data. For example, a useLogin action that logs in a user. Think about it like a "public" action.

src/components/login/login.tsx

import { globalAction$ } from '@builder.io/qwik-city';
 
export const useLogin = globalAction$((data) => {
  // ...
});

Contributors

Thanks to all the contributors who have helped make this documentation better!

routeAction$()

Using actions with <Form/>

Using actions programmatically

Actions with Event Handlers

Validation and type safety

HTTP request and response

Action Failures

Previous form state

Route vs Global actions

routeAction$()

globalAction$()

Contributors

`routeAction$()`

Using actions with `<Form/>`

`routeAction$()`

`globalAction$()`