ko-typed provides observable extensions for restricting and converting observable values based on type. Supports validation.
npm install ko-typed
bower install ko-typed
var ko = require('ko-typed')(require('knockout'));
var typed = ko.observable().extend({ type: 'Undefined|Number' })
var convert = typed.extend({ convert: 'String' })<html>
<head>
<script type="text/javascript" src="knockout.js"></script>
<script type="text/javascript" src="ko-typed.applied.web.min.js"></script>
</head>
<body>
<script>
var typed = ko.observable().extend({ type: 'Undefined|Number' })
var convert = typed.extend({ convert: 'String' })
</script>
</body>
</html>require.config({
paths: {
"knockout": ...,
"ko-typed": "ko-typed.applied.web.min.js"
}
});
require(['knockout', 'ko-typed'], function (ko) {
var typed = ko.observable().extend({ type: 'Undefined|Number' })
var convert = typed.extend({ convert: 'String' })
});ko extenders are used to wrap a given observable and provide a typed interface.
Create a computed observable which only accepts a specified list of types. Does not perform conversions.
Supports:
- Generic types
- Custom types
- Overrides
var base = ko.observable();
var typed = base.extend({ type: 'Undefined|String' });
typed(); // good. undefined is of a supported type.
typed(undefined); // good. undefined is of a supported type.
typed('string'); // good. 'string' is of a supported type.
base(10); typed(); // bad. 10 is not of a supported type.
typed(10); // bad. 10 is not of a supported type.See examples/type for more examples. See test/coverage/type for detailed tests.
Create a computed observable which converts to and from internal and external types.
Supports:
- Type restriction
- Custom conversions
- Default conversions
- Overrides
var base = ko.observable();
var typed = base.extend({ type: 'Undefined|String' });
var converted = typed.extend({ convert: true });
converted('');
assert.strictEqual(base(), undefined);
converted(10);
assert.strictEqual(base(), '10');
converted('string');
assert.strictEqual(base(), 'string');
base(undefined);
assert.strictEqual(converted(), undefined);
base('10');
assert.strictEqual(converted(), '10');
base('string');
assert.strictEqual(converted(), 'string');See examples/convert for more examples. See test/coverage/convert for detailed tests.
Converters between all common types are provided where conversion is common and unambiguous.