wolkenkit-react

Official React bindings for wolkenkit.

Table of Contents

• Installation
• Connecting to an application
  • Connecting manually
• Sending commands
• Reading lists
• Reading a single item of a list
• Experimental API: Using hooks
  • Sending commands
  • Reading lists using the useList hook
  • Reading list items using the useListItem hook
• Running the build
• License

Installation

$ npm install wolkenkit-react

Connecting to an application

First you need to add a reference to your application. For the minimum setup, you have to reference the Application component. The component establishes a connection to the backend and makes it available to all wolkenkit-react components using the Context API, so make sure to use it at the top level of your component tree. It will render its children once the application has been connected:

import { Application } from 'wolkenkit-react';

export class App extends React.Component {
  render () {
    return (
      <Application host={ 'local.wolkenkit.io' } port={ 3000 }>
        <div className='app'>
        </div>
      </Application>
    );
  }
}

Connecting manually

The <Application /> component is well suited for simple use cases where you don't use a state container like MobX or Redux to manage your client state. In scenarios where you actually have a state container, this container will likely connect to your backend and therefore create the wolkenkit application instance. In such scenarios you can setup the connection to the wolkenkit application wherever you like and use the <Provider /> component to make the application available to all the other components inside your tree:

import { Provider } from 'wolkenkit-react';
import React from 'react';
import ReactDom from 'react-dom';

(async () => {
  const application = await wolkenkit.connect(...);

  ReactDom.render((
    <Provider application={ application }>
      <div className='app'></div>
    </Provider>
  ), document.querySelector('#root'));
})();

Sending commands

If you want to send commands from a component use the withWolkenkit function to provide the application to this component as a property. The application is simply an app instance provided by the wolkenkit-client module. So just like the plain client, you can use it to send commands.

Most often you will likely use this method to send commands from event handlers like this…

import { withWolkenkit } from 'wolkenkit-react';

const MyComponent extends React.Component {
  handleSendMessage () {
    const { application } = this.props;

    // Issue a `send` command of the `message` aggregate in the `communication` context.
    application.communication.message().send({
      text: 'Hello react!'
    });
  }

  render () {
    <div>
      <button onClick={ () => this.handleSendMessage() }>Send message</button>
    </div>
  }
};

export default withWolkenkit(MyComponent);

Reading lists

In order to read lists use the List component and provide the name property as well as a render function as a child that serves as a render prop. This function will receive the items of this list as the first parameter.

import { List } from 'wolkenkit-react';

const MessageList = () => (
  <List name={ 'messages' } observe={ true }>
    { messages => <ul className={ 'messages' }>{ messages.map(message => <li key={ message.id }>{ message.text }</li>) }</ul> }
  </List>
);

Set the observe property to true if you would like to read the list and observe future updates to it.

Just like the plain JavaScript SDK you can use the where, orderBy, skip and take properties to filter lists.

<List name={ 'messages' } where={{ likes: { $greaterThan: 100 }}}>
  { messages => … }
</List>
);

Reading a single item of a list

In order to read a single item of a list use the ListItem component and provide the name of the list using the list property as well as a render function as a child that serves as a render prop. This function will receive the item of this list as the first parameter:

import { ListItem } from 'wolkenkit-react';

const MessageDetails = () => (
  <ListItem list={ 'messages' } id='' observe={ true }>
    { item => <div className={ 'message' }>{ message.text }</div> }
  </List>
);

Set the observe property to true if you would like to read the item and observe future updates to it.

Experimental API: Using hooks

With version 16.8.0 React introduced the new Hooks API in order to make stateful logic available to function components. Therefore this package introduces a new API to provide wolkenkit functionality to function components. Please note: this API is still in flux. If you have any questions and concerns about this, feel free to open an issue and give feedback.

Sending commands

If you want to send commands from a function component use the useApplication hook to provide the application. It returns an instance of the plain client that you can use to send commands:

const ChatWithHooks = function () {
  const application = useApplication();
  const [ newMessageText, setNewMessage ] = useState('New message');

  const handleSendMessageClick = function (event) {
    application.communication.message().send({
      text: newMessageText
    });
  };

  render () {
    <div>
      <button onClick={ handleSendMessageClick }>Send message</button>
    </div>
  }
};

Reading lists using the useList hook

In order to read lists use the useList hook and provide the name of the list as first parameter. You can provide additional options using the second parameter. Set the observe property to true if you would like to read the list and observe future updates to it:

import { useList } from 'wolkenkit-react';

const MessageList = () => (
  const [ messages ] = useList('messages', { observe: true });

  return <ul className={ 'messages' }>messages.map(message => <li key={ message.id }>{ message.text }</li>)</ul>);
);

Just like the plain JavaScript SDK you can use the where, orderBy, skip and take options to filter lists:

const [ topMessages ] = useList('messages', { observe: true,  where={{ likes: { $greaterThan: 100 }}}});

Reading list items using the useListItem hook

In order to read a single item of a list use the useListItem hook and provide the name of the list as the first parameter and the id of the item as second parameter. You can provide additional options using the third parameter. Set the observe property to true if you would like to read the list and observe future updates to it:

import { useListItem } from 'wolkenkit-react';

const MessageList = ({ id }) => (
  const [ message ] = useListItem('messages', id, { observe: true });

  if (!message) {
    return null;
  }

  return <div className={ 'message' }>{ message.text }</div>;
);

Running the build

To build this module use roboter.

$ npx roboter

License

The MIT License (MIT) Copyright (c) 2018-2019 Nicolai Süper and the native web.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.