Last active
May 2, 2017 00:25
-
-
Save dwaltrip/3e0b4ad7b0187284a36bcdab674e9a15 to your computer and use it in GitHub Desktop.
Differences in `key` behavior between mithril v0.2.5 and mithril v1
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
<html lang="en"> | |
<head> | |
<meta charset="utf-8"> | |
<title>Mixing keyed and non-keyed Vnodes</title> | |
<!-- <script src="https://unpkg.com/[email protected]/mithril.js"></script> --> | |
<script src="https://unpkg.com/[email protected]/mithril.js"></script> | |
<style> | |
body { margin: 10px; } | |
button { margin-bottom: 10px; } | |
.item-list { display: flex; flex-direction: column; align-items: flex-start; font-size: 15px; color: #333; } | |
.item-wrapper { display: flex; align-items: center; padding: 5px 8px; border: 1px solid #555; margin: 3px; } | |
.item-icon { height: 8px; width: 8px; border-radius: 50%; background: #8da; margin-right: 4px; } | |
.another-div { display: flex; } | |
.extra-stuff { font-size: 12px; color: #999; margin-left: 5px; } | |
</style> | |
</head> | |
<body> | |
<div id='root'></div> | |
<script> | |
// var isMithrilV1 = false; | |
var isMithrilV1 = true; | |
var Item = { | |
// The issue only happens if we store `item` on the component instance, and use that in the view | |
// In Item.view, if we access the passed in attrs/params directly, we won't notice that the component is stale | |
oninit: function(vnode) { this.item = vnode.attrs.item; }, | |
controller: function(params) { this.item = params.item; }, | |
view: function() { | |
var instance = (isMithrilV1 ? this : arguments[0]); | |
return m('.item', instance.item.text); | |
} | |
}; | |
function appComponentInit() { | |
console.log('Currently using ' + (isMithrilV1 ? 'mithril-v1' : 'mithril-v0.2.5')); | |
this.data = [ | |
{ text: '1st item' }, | |
{ text: 'don\'t mix keyed and non-keyed things' }, | |
{ text: 'foo baz' }, | |
{ text: 'the last item' } | |
]; | |
this.swapFirstAndLast = ()=> { | |
this.data = [].concat( | |
this.data.slice(-1).pop(), // last item | |
this.data.slice(1, -1), // everything in between | |
this.data[0] // first item | |
); | |
}; | |
} | |
var App = { | |
oninit: appComponentInit, | |
controller: appComponentInit, | |
view: function() { | |
var instance = (isMithrilV1 ? this : arguments[0]); | |
return m('.app', [ | |
m('button', { onclick: instance.swapFirstAndLast }, 'Swap first & last'), | |
m('.item-list', instance.data.map(item => { | |
var itemContent = m(Item, { item: item, key: item.text }); | |
return m('.item-wrapper', [ | |
m('.item-icon'), | |
/* Nested array isn't needed in v0.2.5 */ | |
itemContent | |
/* Nested array is required to avoid mixing keyed/non-keyed vnodes in v1 | |
otherwise, "swap" button won't work */ | |
// [ itemContent ] | |
]); | |
})) | |
]); | |
} | |
}; | |
m.mount(document.getElementById('root'), App); | |
</script> | |
</body> | |
</html> |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment