`count` variable revert

pull/7180/head
nazar-lazarchuk 5 years ago
parent bb147ea594
commit 876539f78b

@ -1,17 +1,17 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
import Incrementer from './Incrementer.svelte';
import Decrementer from './Decrementer.svelte';
import Resetter from './Resetter.svelte';
let counterValue;
let countValue;
const unsubscribe = counter.subscribe(value => {
counterValue = value;
const unsubscribe = count.subscribe(value => {
countValue = value;
});
</script>
<h1>The counter is {counterValue}</h1>
<h1>The count is {countValue}</h1>
<Incrementer/>
<Decrementer/>

@ -1,8 +1,8 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
function decrement() {
counter.update(n => n - 1);
count.update(n => n - 1);
}
</script>

@ -1,8 +1,8 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
function increment() {
counter.update(n => n + 1);
count.update(n => n + 1);
}
</script>

@ -1,8 +1,8 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
function reset() {
counter.set(0);
count.set(0);
}
</script>

@ -1,3 +1,3 @@
import { writable } from 'svelte/store';
export const counter = writable(0);
export const count = writable(0);

@ -1,11 +1,11 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
import Incrementer from './Incrementer.svelte';
import Decrementer from './Decrementer.svelte';
import Resetter from './Resetter.svelte';
</script>
<h1>The counter is {$counter}</h1>
<h1>The count is {$count}</h1>
<Incrementer/>
<Decrementer/>

@ -1,8 +1,8 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
function decrement() {
counter.update(n => n - 1);
count.update(n => n - 1);
}
</script>

@ -1,8 +1,8 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
function increment() {
counter.update(n => n + 1);
count.update(n => n + 1);
}
</script>

@ -1,8 +1,8 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
function reset() {
counter.set(0);
count.set(0);
}
</script>

@ -1,3 +1,3 @@
import { writable } from 'svelte/store';
export const counter = writable(0);
export const count = writable(0);

@ -1,9 +1,9 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
</script>
<h1>The counter is {$counter}</h1>
<h1>The count is {$count}</h1>
<button on:click={counter.increment}>+</button>
<button on:click={counter.decrement}>-</button>
<button on:click={counter.reset}>reset</button>
<button on:click={count.increment}>+</button>
<button on:click={count.decrement}>-</button>
<button on:click={count.reset}>reset</button>

@ -1,6 +1,6 @@
import { writable } from 'svelte/store';
function createCounter() {
function createCount() {
const { subscribe, set, update } = writable(0);
return {
@ -11,4 +11,4 @@ function createCounter() {
};
}
export const counter = createCounter();
export const count = createCount();

@ -1,17 +1,17 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
import Incrementer from './Incrementer.svelte';
import Decrementer from './Decrementer.svelte';
import Resetter from './Resetter.svelte';
let counterValue;
let countValue;
counter.subscribe(value => {
counterValue = value;
const unsubscribe = count.subscribe(value => {
countValue = value;
});
</script>
<h1>The counter is {counterValue}</h1>
<h1>The count is {countValue}</h1>
<Incrementer/>
<Decrementer/>

@ -1,5 +1,5 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
function decrement() {
// TODO decrement the count

@ -1,5 +1,5 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
function increment() {
// TODO increment the count

@ -1,5 +1,5 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
function reset() {
// TODO reset the count

@ -1,3 +1,3 @@
import { writable } from 'svelte/store';
export const counter = writable(0);
export const count = writable(0);

@ -1,17 +1,17 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
import Incrementer from './Incrementer.svelte';
import Decrementer from './Decrementer.svelte';
import Resetter from './Resetter.svelte';
let counterValue;
let countValue;
counter.subscribe(value => {
counterValue = value;
count.subscribe(value => {
countValue = value;
});
</script>
<h1>The counter is {counterValue}</h1>
<h1>The count is {countValue}</h1>
<Incrementer/>
<Decrementer/>

@ -1,8 +1,8 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
function decrement() {
counter.update(n => n - 1);
count.update(n => n - 1);
}
</script>

@ -1,8 +1,8 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
function increment() {
counter.update(n => n + 1);
count.update(n => n + 1);
}
</script>

@ -1,8 +1,8 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
function reset() {
counter.set(0);
count.set(0);
}
</script>

@ -1,3 +1,3 @@
import { writable } from 'svelte/store';
export const counter = writable(0);
export const count = writable(0);

@ -4,15 +4,15 @@ title: Writable stores
Not all application state belongs inside your application's component hierarchy. Sometimes, you'll have values that need to be accessed by multiple unrelated components, or by a regular JavaScript module.
In Svelte, we do this with *stores*. A store is simply an object with a `subscribe` method that allows interested parties to be notified whenever the store value changes. In `App.svelte`, `counter` is a store, and we're setting `counterValue` in the `counter.subscribe` callback.
In Svelte, we do this with *stores*. A store is simply an object with a `subscribe` method that allows interested parties to be notified whenever the store value changes. In `App.svelte`, `count` is a store, and we're setting `countValue` in the `count.subscribe` callback.
Click the `stores.js` tab to see the definition of `counter`. It's a *writable* store, which means it has `set` and `update` methods in addition to `subscribe`.
Click the `stores.js` tab to see the definition of `count`. It's a *writable* store, which means it has `set` and `update` methods in addition to `subscribe`.
Now go to the `Incrementer.svelte` tab so that we can wire up the `+` button:
```js
function increment() {
counter.update(n => n + 1);
count.update(n => n + 1);
}
```
@ -22,6 +22,6 @@ Finally, in `Resetter.svelte`, implement `reset`:
```js
function reset() {
counter.set(0);
count.set(0);
}
```

@ -1,17 +1,17 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
import Incrementer from './Incrementer.svelte';
import Decrementer from './Decrementer.svelte';
import Resetter from './Resetter.svelte';
let counterValue;
let countValue;
counter.subscribe(value => {
counterValue = value;
count.subscribe(value => {
countValue = value;
});
</script>
<h1>The counter is {counterValue}</h1>
<h1>The count is {countValue}</h1>
<Incrementer/>
<Decrementer/>

@ -1,8 +1,8 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
function decrement() {
counter.update(n => n - 1);
count.update(n => n - 1);
}
</script>

@ -1,8 +1,8 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
function increment() {
counter.update(n => n + 1);
count.update(n => n + 1);
}
</script>

@ -1,8 +1,8 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
function reset() {
counter.set(0);
count.set(0);
}
</script>

@ -1,3 +1,3 @@
import { writable } from 'svelte/store';
export const counter = writable(0);
export const count = writable(0);

@ -1,11 +1,11 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
import Incrementer from './Incrementer.svelte';
import Decrementer from './Decrementer.svelte';
import Resetter from './Resetter.svelte';
</script>
<h1>The counter is {$counter}</h1>
<h1>The count is {$count}</h1>
<Incrementer/>
<Decrementer/>

@ -1,8 +1,8 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
function decrement() {
counter.update(n => n - 1);
count.update(n => n - 1);
}
</script>

@ -1,8 +1,8 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
function increment() {
counter.update(n => n + 1);
count.update(n => n + 1);
}
</script>

@ -1,8 +1,8 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
function reset() {
counter.set(0);
count.set(0);
}
</script>

@ -1,3 +1,3 @@
import { writable } from 'svelte/store';
export const counter = writable(0);
export const count = writable(0);

@ -7,8 +7,8 @@ The app in the previous example works, but there's a subtle bug — the store is
Start by declaring `unsubscribe` in `App.svelte`:
```js
const unsubscribe = counter.subscribe(value => {
counterValue = value;
const unsubscribe = count.subscribe(value => {
countValue = value;
});
```
> Calling a `subscribe` method returns an `unsubscribe` function.
@ -18,38 +18,38 @@ You now declared `unsubscribe`, but it still needs to be called, for example thr
```html
<script>
import { onDestroy } from 'svelte';
import { counter } from './stores.js';
import { count } from './stores.js';
import Incrementer from './Incrementer.svelte';
import Decrementer from './Decrementer.svelte';
import Resetter from './Resetter.svelte';
let counterValue;
let countValue;
const unsubscribe = counter.subscribe(value => {
counterValue = value;
const unsubscribe = count.subscribe(value => {
countValue = value;
});
onDestroy(unsubscribe);
</script>
<h1>The counter is {counterValue}</h1>
<h1>The count is {countValue}</h1>
```
It starts to get a bit boilerplatey though, especially if your component subscribes to multiple stores. Instead, Svelte has a trick up its sleeve — you can reference a store value by prefixing the store name with `$`:
```html
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
import Incrementer from './Incrementer.svelte';
import Decrementer from './Decrementer.svelte';
import Resetter from './Resetter.svelte';
</script>
<h1>The counter is {$counter}</h1>
<h1>The count is {$count}</h1>
```
> Auto-subscription only works with store variables that are declared (or imported) at the top-level scope of a component.
You're not limited to using `$counter` inside the markup, either — you can use it anywhere in the `<script>` as well, such as in event handlers or reactive declarations.
You're not limited to using `$count` inside the markup, either — you can use it anywhere in the `<script>` as well, such as in event handlers or reactive declarations.
> Any name beginning with `$` is assumed to refer to a store value. It's effectively a reserved character — Svelte will prevent you from declaring your own variables with a `$` prefix.

@ -1,9 +1,9 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
</script>
<h1>The counter is {$counter}</h1>
<h1>The count is {$count}</h1>
<button on:click={counter.increment}>+</button>
<button on:click={counter.decrement}>-</button>
<button on:click={counter.reset}>reset</button>
<button on:click={count.increment}>+</button>
<button on:click={count.decrement}>-</button>
<button on:click={count.reset}>reset</button>

@ -1,6 +1,6 @@
import { writable } from 'svelte/store';
function createCounter() {
function createCount() {
const { subscribe, set, update } = writable(0);
return {
@ -11,4 +11,4 @@ function createCounter() {
};
}
export const counter = createCounter();
export const count = createCount();

@ -1,9 +1,9 @@
<script>
import { counter } from './stores.js';
import { count } from './stores.js';
</script>
<h1>The counter is {$counter}</h1>
<h1>The count is {$count}</h1>
<button on:click={counter.increment}>+</button>
<button on:click={counter.decrement}>-</button>
<button on:click={counter.reset}>reset</button>
<button on:click={count.increment}>+</button>
<button on:click={count.decrement}>-</button>
<button on:click={count.reset}>reset</button>

@ -1,6 +1,6 @@
import { writable } from 'svelte/store';
function createCounter() {
function createCount() {
const { subscribe, set, update } = writable(0);
return {
@ -11,4 +11,4 @@ function createCounter() {
};
}
export const counter = createCounter();
export const count = createCount();

@ -4,10 +4,10 @@ title: Custom stores
As long as an object correctly implements the `subscribe` method, it's a store. Beyond that, anything goes. It's very easy, therefore, to create custom stores with domain-specific logic.
For example, the `counter` store from our earlier example could include `increment`, `decrement` and `reset` methods and avoid exposing `set` and `update`:
For example, the `count` store from our earlier example could include `increment`, `decrement` and `reset` methods and avoid exposing `set` and `update`:
```js
function createCounter() {
function createCount() {
const { subscribe, set, update } = writable(0);
return {

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