Isomor-react

Isomor-react is a library that will help you to use isomor with react. When you are using isomor wihtout this library each call to server functions will generate a request. Isomor-react will create a cache and distinct duplicated request. It will also allow you to share the response to a server function between multiple components.

Example

Get response

Without cache you would do:

import { getTime } from './server/getTime';
 
export const Time = () => {
  const [time, setTime] = React.useState<string>();
  const load = async () => {
      setTime(await getTime());
  }
  React.useEffect(() => { load(); }, []);
  return (
    <div>
      {!time ? <p>Loading...</p> : (
        <p><b>Server time:</b> {time} <button onClick={load}>reload</button></p>
      )}
    </div>
  );
}

Using the cache:

import React from 'react';
import { useIsomor } from 'isomor-react';
 
import { getTime } from './server/getTime';
 
export const Time = () => {
  const { call, response } = useIsomor();
  const load = () => {
    call(getTime);
  }
  React.useEffect(() => { load(); }, []);
  return (
    <div>
      {!response ? <p>Loading...</p> : (
        <p><b>Server time:</b> {response.time} <button onClick={load}>reload</button></p>
      )}
    </div>
  );
}

Without cache, if you would have this component 2 times in your app, it would make 2 requests when the components mount. When you click the load button, only the component where the button is located would be refreshed. With the cache, only 1 request would be sent instead of 2. When you click the load button, both component would be refresh.

Update response

isomor-react has also a mecanism to update the cache, so you don't have to refetch data.

import React from 'react';
import { useIsomor } from 'isomor-react';
 
import { getTime } from './server/getTime';
import { setTime } from './server/setTime';
 
export const Time = () => {
  const { call, response, update } = useIsomor();
  const load = () => {
    call(getTime);
  }
  React.useEffect(() => { load(); }, []);
  const onClickUpdate = (newColor: string) => async () => {
    const newTime = await setTime('08:00');
    update(newTime, getTime);
  }
  return (
    <div>
      {!response ? <p>Loading...</p> : (
        <p>
          <b>Server time:</b> {response.time}
          <button onClick={load}>reload</button>
          <button onClickUpdate={load}>update</button>
        </p>
      )}
    </div>
  );
}

When you click the button update, the update request is sent to the server, when the response is received, the cache is updated and the 2 components get updated.

How to use it

Isomor-react is using the context api to share the state between component. So the first thing you need to do is to call the context provider in the root of your app:

import { IsomorProvider } from 'isomor-react';
 
ReactDOM.render((
    <IsomorProvider>
        <App />
    </IsomorProvider>
), document.getElementById('root'));
 

The you just have to use the hook useIsomor. This hook return an object of 3 values: call, update and response.

import { useIsomor } from 'isomor-react';
 
export const MyComponent = () => {
    const { call, response, update } = useIsomor();
    ...
}

call is a function that allow you to cache your original function call. The first parameter you give to call is the function you want to cache. The next parameter are the parameters you would have provide to the function you want to cache.

async call(fn: (...args: any) => Promise<any>, ...args: any)

eg.:

await call(getItems);
await call(getItem, 'id-20', { withComment: true });

response is the response received after the function has been called.

update is a function that allow you to update the cache without to make a call to the server. The first parameter is the new response you want to set. The second parameter is the cached function. The next parameter are the parameters you would have provide to the cached function.

eg.:

await update([
    {id:'id-1', title: 'hello'},
    {id:'id-2', title: 'hello2'},
], getItems);
await update({
    id:'id-1',
    title: 'hello',
    content: 'Lorem ipsum dolor sit amet, ac augue malesuada, tellus amet',
    comments: [],
}, getItem, 'id-20', { withComment: true });

ToDo

• error handling
• provide loading variable
• batch queries?