ampersand-multiselect-view

ampersand-multiselect-view

Lead Maintainer: Kyle Farris (@kylefarris)

overview

A view module for intelligently rendering and validating selectbox input. Works well with ampersand-form-view. Based off of ampersand-select-view.

install

npm install ampersand-multiselect-view

Part of the Ampersand.js toolkit for building clientside applications.

API Reference

clear() - [Function] - returns this

Alias to calling setValue(null, true). Unselects all options.

reset() - [Function] - returns this

Sets the selected option and view value to the original option value provided during construction.

setValue([value, skipValidationMessage]) - [Function] - returns this

Sets the selected options to those which match the provided value(s). Updates the view's .value accordingly. MultiSelectView will error if no matching options exist.

constructor - [Function] new MultiSelectView([options])

options

general options

• autoRender: [default: false] generally, we leave rendering of this FieldView to its controlling form
• name: the <select>'s name attribute's value. Used when reporting to parent form
• parent: parent form reference
• options: array/collection of options to render into the select box
• [el]: element if you want to render the view into
• [template]: a custom template to use (see 'template' section, below, for more)
• [required]: [default: false] field required
• [eagerValidate]: [default: false] validate and show messages immediately. Note: field will be validated immediately to provide a true .valid value, but messages by default are hidden.
• [value]: initial value(s) (array) for the <select>. value must be a members of the options set.

label & validation options

• [label]: [default: name value] text to annotate your select control
• [invalidClass]: [default: 'select-invalid'] class to apply to root element if invalid
• [validClass]: [default: 'select-valid'] class to apply to root element if valid
• [requiredMessage]: [default: 'Selection required'] message to display if invalid and required

collection option set

If using a collection to produce <select> <option>s, the following may also be specified:

• [disabledAttribute]: boolean model attribute to flag disabling of the option node
• [idAttribute]: model attribute to use as the id for the option node. This will be returned by SelectView.prototype.value
• [textAttribute]: model attribute to use as the text of the option node in the select box
• [yieldModel]: [default: true] if options is a collection, yields the full model rather than just its idAttribute to .value

When the collection changes, the view will try and maintain its currently .value. If the corresponding model is removed, the <select> control will default to the 0th index <option> and update its value accordingly.

custom template

You may override the default template by providing your own template string to the constructor options hash. Technically, all you must provided is a <select> element. However, your template may include the following under a single root element:

1. An element with a data-hook="label" to annotate your select control
2. An <select> element to hold your options with the multiple or multiple="multiple" attribute.
3. An element with a data-hook="message-container" to contain validation messages
4. An element with a data-hook="message-text" nested beneath the data-hook="message-container" element to show validation messages

Here's the default template for reference:

<label class="select">
    <span data-hook="label"></span>
    <select multiple="multiple"></select>
    <span data-hook="message-container" class="message message-below message-error">
        <p data-hook="message-text"></p>
    </span>
</label>

example

var FormView = require('ampersand-form-view');
var MultiSelectView = require('ampersand-multiselect-view');


module.exports = FormView.extend({
    fields: function () {
        return [
            new MultiSelectView({
                label: 'Pick some colors!',
                // actual field name
                name: 'color',
                parent: this,
                // you can pass simple string options
                options: ['blue', 'orange', 'red'],
                // you can specify that they have to pick at least one
                required: true
            }),
            new MultiSelectView({
                name: 'option',
                parent: this,
                // you can also pass array, first is the value, second is used for the label
                // and an optional third value can used to disable the option
                options: [ ['a', 'Option A'], ['b', 'Option B'], ['c', 'Option C', true] ]
            }),
            new MultiSelectView({
                name: 'model',
                parent: this,
                // you can pass in a collection here too
                options: collection,
                // and pick some item from the collection as the selected ones
                value: [collection1.at(2), collection1.at(5)],
                // here you specify which attribute on the objects in the collection
                // to use for the value returned.
                idAttribute: 'id',
                // you can also specify which model attribute to use as the title
                textAttribute: 'title',
                // you can also specify a boolean model attribute to render items as disabled
                disabledAttribute: 'disabled',
                // here you can specify if it should return the selected model(s) from the
                // collection, or just the id attribute(s).  defaults `true`
                yieldModel: false
            })
        ];
    }
});

gotchas

• Numeric option values are generally stringified by the browser. Be mindful doing comparisons. You'll generally desire to inspect selectView.value (the value of your selected options' input) over selectView.select.value (the value returned from the browser).
  • Additionally, do not use option sets containing values that == one another. E.g., do not use options whose values are "2" (string) and 2 (number). Browsers cannot distinguish between them in the select control context, thus nor can ampersand-select-view.
• null, undefined, or '' option values are not considered valid when the field is required. This does not apply when options are from a collection and yieldModel is enabled.

browser support

changelog

• We're still on the beta version!

credits

Based considerably off of the ampersand-select-view by Christopher Dieringer (@cdaringe).

contributing

Do it. This is still experimental--I can use all the help I can get!

license

MIT