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Dec 9, 2016
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Modification to docs/basics/Reducers to make imports more clear. This… #2142

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Modification to docs/basics/Reducers to make imports more clear. This…
Dec 7, 2016
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Removed instructions on importing SET_VISIBILITY_FILTER
Dec 9, 2016
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10 changes: 8 additions & 2 deletions docs/basics/Reducers.md
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Expand Up @@ -115,7 +115,7 @@ Note that:

## Handling More Actions

We have two more actions to handle! Let's extend our reducer to handle `ADD_TODO`.
We have two more actions to handle! Just like we did with `SET_VISIBILITY_FILTER`, we'll import the `ADD_TODO` and `TOGGLE_TODO` actions and then extend our reducer to handle `ADD_TODO`.

```js
function todoApp(state = initialState, action) {
Expand Down Expand Up @@ -244,8 +244,14 @@ function todoApp(state = initialState, action) {

Note that `todos` also accepts `state`—but it's an array! Now `todoApp` just gives it the slice of the state to manage, and `todos` knows how to update just that slice. **This is called *reducer composition*, and it's the fundamental pattern of building Redux apps.**

Let's explore reducer composition more. Can we also extract a reducer managing just `visibilityFilter`? We can:
Let's explore reducer composition more. Can we also extract a reducer managing just `visibilityFilter`? We can.

Below our imports, let's use [ES6 Object Destructuring](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment) to declare `SHOW_ALL`:
```js
const { SHOW_ALL } = VisibilityFilters;
```

Then:
```js
function visibilityFilter(state = SHOW_ALL, action) {
switch (action.type) {
Expand Down