Angular Selection Model

Angular directive for managing selections in tables and lists

Huh? What about ngGrid, ngTable, or ...

They are all great at what they do and selectionModel is not meant to be a replacement for any of those things. selectionModel works directly with the ngRepeat directive, it does nothing other than keep track of which of the iterated over items are selected.

How does it work? The directive looks for a particular attribute on your collection items, by default that's selected. When an item becomes selected that attribute is set to true... when it gets deselected (surprise) it's set to false. You can programmatically flip the state of that attribute as well and the directive will respond by updating your view. For convenience we also expose a read only list of just the selected items.

So when should you use selectionModel? You might consider it if:

• You want to make a list or table selectable but don't need lots extra bells and whistles.
• You want a grid/list whose styles painlessly match the rest of your app.
• You're making your own fancy grid directive and want to offload selection management.

Here's a simple example, we'll start with the controller:

angular.module('myApp').controller('FancyStuffCtrl', function() {
  this.stuff = [
    {selected: false, label: 'Scotchy scotch'},
    {selected: true, label: 'Monacle'},
    {selected: true, label: 'Curly mustache'},
    {selected: false, label: 'Top hat'}
  ];
});

and the markup:

<ul ng-controller="FancyStuffCtrl as fancy">
  <li ng-repeat="item in fancy.stuff" selection-model>
    {{$index+1}}: {{item.label}}
  </li>
</ul>

(don't forget to include the selectionModel module in you app).

angular.module('myApp', ['selectionModel']);

That's it! Your list will key in on the "selected" attribute by default, respond to mouse clicks, and reflect programmatic changes to stuff.

Pieces of flare

So how do you let the user know about their selection? By default selectionModel adds a selected class to its selected li or tr. It's up to you to style those elements differently. If you're using checkboxes you can also have their checked state match the item's selected state.

Going farther

You can customize the behavior of your selection model by setting different attributes on your ngRepeated element.

selectionModelType

Type: String Default: ''basic'`

Supports either 'basic' or 'checkbox'. When set to checkbox the directive will look for the first input element of type checkbox in each item and update its selected status to match the state of the item.

<table>
  <tr ng-repeat="item in fancy.stuff"
      selection-model
      selection-model-type="'checkbox'">
    <td><input type="checkbox"></td>
    <td>{{$index+1}}</td>
    <td>{{item.label}}</td>
  </tr>
</table>

Note that you do not need to manually set the checkbox state.

selectionModelMode

Type: String Default: 'single'

May be be either 'single', 'multiple', or 'multiple-additive'. Make use of the multi* modes to allow the user select more than one item at a time.

The behavior of the multi select mode is modeled after ExtJS data grids. By default a vanilla click (no shift or ctrl) will set the entire selection to the single item clicked. Use multiple-additive to have vanilla clicks add to the selection (and remove when the item is already selected).

<table>
  <tr ng-repeat="item in fancy.stuff"
      selection-model
      selection-model-mode="'multiple-additive'">
    <td>{{$index+1}}</td>
    <td>{{item.label}}</td>
  </tr>
</table>

selectionModelSelectedAttribute

Type: String Default: 'selected'

The collection attribute used to track the selected status of your collection items. Note that you can set this globally using selectionModelOptionsProvider.

<ul>
  <li ng-repeat="item in fancy.stuff"
      selection-model
      selection-model-selected-attribute="'checked'">
    <!-- Now selection-model will use `item.checked` instead of `item.selected` -->
    {{item.label}}
  </li>
</ul>

selectionModelSelectedClass

Type: String Default: 'selected'

The class name selection-model assigns to selected items in your view. Note that you can set this globally using selectionModelOptionsProvider.

<ul>
  <li ng-repeat="item in fancy.stuff"
      selection-model
      selection-model-selected-class="'checked'">
    <!-- Now selection-model will assign a classname of `checked` to select list items-->
    {{item.label}}
  </li>
</ul>

selectionModelCleanupStrategy

Type: String Default: 'none'

By default this directive will not change the selected state of your repeated over collection items as they come in and out of view. In many cases you may want items to be automatically deselected as they are filtered away or the user "pages" a grid view. Use 'deselect' to get this behavior.

Example: John is looking at page 1 of a data grid and selects some items. John changes his mind, goes to the second page of data, selects different items and then hits the submit button. Using the cleanup strategy none all items from the first page that John left selected would still be selected, with the deselect strategy though those items would have been deselected when he changed pages and only the second page items would be selected.

<table>
  <tr ng-repeat="item in fancy.stuff"
      selection-model
      selection-model-cleanup-strategy="'deselect'">
    <td>{{$index+1}}</td>
    <td>{{item.label}}</td>
  </tr>
</table>

selectionModelSelectedItems

Type: Array Default: undefined

If used this should resolve to an initially empty array. The directive will keep the contents of that array up to date with the selection in your collection. Note that this is a read only list. Adding items will have no effect on your collection - and order is not guarenteed.

Also keep in mind that unless you're using a mode which allows for more than one selected item this will always be an array of length 1.

In your controller:

myApp.controller('SillyCtrl', function() {
  this.items = [ /* a bunch of stuff */ ];

  // Should start empty even if you have an initial selection
  this.selectedItems = []; 
});

In your view

<div ng-controller="SillyCtrl as silly">
  <ul>
    <li ng-repeat="item in silly.items"
        selection-model
        selection-model-mode="'multiple-additive'"
        selection-model-selected-items="silly.selectedItems">
      Click me!
    </li>
  </ul>

  <p>
    You've selected {{silly.selectedItems.length}} item(s)
  </p>
</div>

selectionModelOnChange

Type: Expression Default: undefined

Use this attribute to register a callback for when the selected state of a collection item changes.

In your controller:

myApp.controller('SillyCtrl', function() {
  this.items = [ /* a bunch of stuff */ ];
  this.changed = function(item) {
    // Do something with item, its selected status has changed!
  }
});

In your view:

<div ng-controller="SillyCtrl as silly">
  <ul>
    <li ng-repeat="item in silly.items"
        selection-model
        selection-model-mode="'multiple-additive'"
        selection-model-on-change="silly.changed(item)">
      Click me!
    </li>
  </ul>

  <p>
    You've selected {{silly.selectedItems.length}} item(s)
  </p>
</div>

Extras

selectionModelIgnore

A helper directive you can use to tell selectionModel to selectively ignore clicks on certain elements. This is useful in cases where you need to manage selection changes yourself or you don't selections to change at all (think "delete" buttons).

<div ng-controller="SillyCtrl as silly">
  <ul>
    <li ng-repeat="item in silly.items"
        selection-model
        selection-model-mode="'multiple-additive'"
        selection-model-on-change="silly.changed(item)">
      Click me!
      <button selection-model-ignore class="close">
        &times;
      </button>
    </li>
  </ul>

This directive is dynamic, if the value assigned to selectionModelIgnore is falsey at the time of the click the click will not be ignored:

<div ng-controller="SillyCtrl as silly">
  <ul>
    <li ng-repeat="item in silly.items"
        selection-model
        selection-model-mode="'multiple-additive'"
        selection-model-on-change="silly.changed(item)">
      Click me!
      <button selection-model-ignore="false" class="close">
        &times; (NOT ignored)
      </button>
      <button selection-model-ignore="true" class="close">
        &times; (ignored)
      </button>
    </li>
  </ul>

Providing Configuration

The selectionModelOptionsProvider

Use the selectionModelOptionsProvider in your module's config method to set global options.

myApp.config(function(selectionModelOptionsProvider) {
  selectionModelOptionsProvider.set({
    selectedAttribute: 'mySelectedObjectAttribute',
    selectedClass: 'my-selected-dom-node',
    type: 'checkbox',
    mode: 'multiple-additive',
    cleanupStrategy: 'deselect'
  });
});

Even more...

Check out the docs (as soon as I hit the codebase with dox that is...)

Limitations and common pitfalls

• You must use the single parent form of ngRepeat. I.e. if you're trying to use this module with ng-repeat-start and ng-repeat-end you won't have much joy.
• ngRepeat expressions that break reference to items in your collection are not supported. If your express looks like 'item in array | pluck:attributesHash' you won't have much joy. I.e. at the end of the day 'item' should be an actual element in 'array'.
• This directive works by reading from and assigning to an attribute on the items in your collection. If you are worried about polluting your items' attributes consider using the selectionModelOptions provider to make the attribute more obscure or wrapping your items in something like {selected: false, payload: item}.
• At present selection-model listens for clicks anywhere on the repeated element. If you have a child element that programmatically changes your collection item's selected state when clicked you may end up bumping heads with selection-model. Be wary of this when it seems like your selection is not changing and you have your own click handlers registered to change the selection. For such cases we provide the selectionModelIgnore helper directive.
• Do not rely on selection-model to maintain the state of your collections outside the view. For example, don't mark an item as selected in controller code then send your collection to the backend server expecting selection-model to have appropriately deselected other items. Doing so creates an undesireable coupling with angular's digest cycle. Instead, when making manual selection changes, you should take care to make all appropriate selections and deselections if you need immediate consistency.

Running tests

Install dependencies with npm and bower then run grunt test. You'll need the grunt-cli module installed globally.

Running examples

Install dependencies with npm and bower then run grunt server. You'll need the grunt-cli module installed globally. Run this way the examples will reload automatically as you make changes within the examples folder or to the source files themselves.

You may also simply open examples/index.html with your favorite web browser if the whole grunt thing isn't your cup of tea.

Getting help

Use the tag angular-selection-model on Stack Overflow. For quick things I can be reached on twitter @jusrussell. A plunk/jsbin/fiddle is worth a thousand words.

Release history

• 2015-10-08 v0.10.0 BREAKING CHANGES - see MIGRATING.md
• 2015-09-21 v0.9.0 Make selectionModelIgnore dynamic
• 2014-10-29 v0.8.3 Don't double count label clicks
• 2014-07-08 v0.7.0 Added support selectionModelOnChange attribute
• 2014-02-27 v0.5.0 Checkbox clicks should affect no other rows
• 2014-01-15 v0.4.1 Correctly remove filtered out elements from selected items list
• 2014-01-10 v0.4.0 Expose read only list of selected items
• 2014-01-08 v0.3.0 Add selectionModelOptionsProvider for global configuration
• 2013-12-30 v0.2.0 Add new mode multi-additive.
• 2013-12-30 v0.1.2 Deselect filtered out items.
• 2013-12-28 v0.1.1 Initial release.

License

MIT