Local storage Tags API example

index.marko

<local/count=0 storageKey="count"/>
<p>You clicked ${count} times</p>
<button onClick() { count++ }>
  Click me
</button>

local.marko

<!-- local.marko -->
<attrs/{ default: initialValue, storageKey }/>

<const/stored=localStorage.getItem(storageKey)/>
<let/store=stored ? JSON.parse(stored) : initialValue/>
<effect() { localStorage.setItem(storageKey, JSON.stringify(store)) }/>

<return:=store/>