Reselect Change Memoize


A simple memoize function for reselect which performs a callback everytime the result changes.

This package contains three exports:
* a changeMemoize
* createSelectorWithChangeCallback which allows you to easily substitute createSelector
* a createSelector helper which enables change logging if not in production and allows you to name selectors

changeMemoize

``js
import { createSelectorCreator } from 'reselect';
import { changeMemoize } from 'reselect-change-memoize';

const myCallback = function(lastArgs, lastResult, newArgs, newResult) {
// Your code
};

const createSelector = createSelectorCreator(changeMemoize, myCallback);
`

createSelectorWithChangeCallback

`js
import { createSelectorWithChangeCallback } from 'reselect-change-memoize';

const myCallback = function(lastArgs, lastResult, newArgs, newResult) {
// Your code
};

const selector = createSelectorWithChangeCallback(
myCallback,
(state) => state,
(state) => {
return { state };
}
);

selector({ initial: 'state' });
`

createSelector

`js
import { createSelector } from 'reselect-change-memoize';

const selector1 = createSelector(
'An awesome selector',
(state) => state,
(state) => {
return { selector1: state };
}
);
const selector2 = createSelector(
'A second awesome selector which uses the first awesome selector',
selector1,
(state) => {
return { selector2: state };
}
);
// The name doesn't have to be provided
const selector3 = createSelector(
selector1,
(state) => {
return { selector2: state };
}
);
selector2({ initial: 'state' });
selector1({ second: 'state' });
selector3({ second: 'state' });
`

produces

`
- An awesome selector (0.06ms)
lastArgs {}
lastResult {}
newArgs [ { initial: 'state' } ]
newResult { selector1: { initial: 'state' } }
- A second awesome selector which uses the first awesome selector (0.05ms)
lastArgs {}
lastResult {}
newArgs [ { selector1: { initial: 'state' } } ]
newResult { selector2: { selector1: { initial: 'state' } } }
- An awesome selector (0.01ms)
lastArgs [ { initial: 'state' } ]
lastResult { selector1: { initial: 'state' } }
newArgs [ { second: 'state' } ]
newResult { selector1: { second: 'state' } }
- unknown (0.03ms)
lastArgs {}
lastResult {}
newArgs [ { second: 'state' } ]
newResult { selector3: { second: 'state' } }
``