racker/ko-validation

Name: ko-validation

Owner: racker

Description: Knockout Validation Plugin for the Rackspace Control Panel.

Created: 2013-12-05 17:51:48.0

Updated: 2017-09-03 08:16:31.0

Pushed: 2015-10-07 17:30:35.0

Homepage: null

Size: 1542

Language: JavaScript

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README

ko-validation Build Status

Knockout Validation Plugin (used by the Rackspace Control Panel)

Getting Started

Just hook up validation to your knockout observables:

View Model:

ewModel = function () {
is['name'] = ko.observable('John Doe').extend({
'required': ['Name is required.'], // will show the message "Name is required."
'maxLength': [30, 'Name cannot be longer than 30 characters.'] // the last item is the message that will be shown
;

is['phone'] = ko.observable().extend({
'regex': [/[0-9]/, 'Must contain numbers.']
;

Template:

>
nput type="text" data-bind="value: name">
nput type="text" data-bind="value: phone">
v>

By default, the plugin will insert a span in the parent element of the input that is bound to that observable, and show the validation messages there.

Validation Rules

Currently the following rules are supported:

Deprecated validators

Please refer to integration specs for examples

Validating Computed Observables

Sometimes we want to have multiple fields behave as a single field for validation purposes.

You can add an observable for each field and a computed observable with the final value, and have the computed observable be validated.

One example is if you have a text field alongside a select drop-down to select a time range, allowing the user to enter a number in the text field, and an option out of “Minutes, Hours, Days” in the select.

That would look like:

View Model:

['time'] = ko.observable();

['timeUnit'] = ko.observable('minutes');

['timeInMinutes'] = ko.computed(function () {
turn convertToMinutes(this['time'](), this['timeUnit']());
his).extend({
alidatesAfter': [this['time'], this['timeUnit']],
equired': ['Time is required.'],
ange': [0, (60 * 24), 'Cooldown must be between 0 minutes and 1 day.']

And, on the template:

>
nput type="text" data-bind="value: time">
elect data-bind="value: timeUnit">
v>

Notice the validationAfter extension passed to timeInMinutes. That means that observable will be validated after changes on both time and timeUnit, and the error message will be shown by the input fields associated to each of them.

Validating Related Fields

In some cases, the validation for one field may depend on the value of another field. For example, one field might only be required if another field has a particular value. For fields like this, the validation should be re-run whenever either field changes. The validates extension allows you to indicate fields that should be validated whenever the given observable is changed. In the example below, the range validator on field1 will be run again whenever the value of field2 is changed:

['field1'] = ko.observable(1).extend({
ange': [1, 10, 'Must be between 1 and 10']

['field2'] = ko.observable(2).extend({
alidates': [this['field1']]

Validating Checkboxes

Validating that at least one checkbox is checked in a checkbox group is as easy as extending an observable array with the checkboxes values to be required. One problem that this solution could cause is that a validation message would be inserted after each checkbox. To ensure only one validation message is inserted somewhere, use the validationMessage binding:

View Model:

['reasonsToCancelAccount'] = ko.observableArray([]).extend({
equired': ['Choose at least one please']

Template:

>
l>
<li><input type="checkbox" data-bind="checked: reasonsToCancelAccount" value="reason1"/>R1</li>
<li><input type="checkbox" data-bind="checked: reasonsToCancelAccount" value="reason2"/>R2</li>
<li><input type="checkbox" data-bind="checked: reasonsToCancelAccount" value="reason3"/>R3</li>
ul>
pan data-bind="validationMessage: reasonsToCancelAccount"></span>
v>

When an element with validationMessage binding exists, new elements for displaying validation messages will not be automatically inserted in the DOM.

Contributing

If you want to contribute to ko-validation, you will need npm and grunt-cli.

After installing the dependencies with npm, run grunt watch to start the test watcher, which will run the tests in both Chrome and Firefox every time a file is modified. You can also use grunt karma:ci to run all the tests with PhantomJS.

When submitting a pull request, do not forget to add unit tests, and if you are introducing a new validator, please also add integration tests for it.

To create a new distribution file with a patch version, run npm version patch -m "Upgrade to %s for reasons" (with whatever is the most appropriate message), then run grunt dist to generate the minified concatenated dist file. You can then npm publish the new version to npm.

When creating a new version

The rules are:


This work is supported by the National Institutes of Health's National Center for Advancing Translational Sciences, Grant Number U24TR002306. This work is solely the responsibility of the creators and does not necessarily represent the official views of the National Institutes of Health.