Watches form fields and runs a callback when a value changes.
Only fields with a [name] attribute can be watched.
The programmatic variant of this is the up.watch() function.
Example
The following would run a log whenever the <input> changes:
<input name="query" up-observe="console.log('New value', value)">
Callback context
The script given to [up-watch] runs with the following context:
| Name |
Type |
Description |
this |
Element |
The changed form field |
name |
Element |
The [name] of the changed field |
value |
string |
The new value of the changed field |
Watching multiple fields
You can set [up-watch] on any element to observe all contained fields.
The name argument contains the name of the field that was changed.
