Q1. Suppose I want to alter the look of each "item" that a user marks for deletion before the main "delete" button is pressed. (This immediate visual feedback should eliminate the need for the proverbial "are you sure?" dialog box.) The user will check checkboxes to indicate which items should be deleted. If a checkbox is unchecked, that item should revert back to its normal look.
What's the best way to apply or remove the CSS styling?
Q2. Suppose I want to allow each user to personalize how my site is presented. E.g., select from a fixed set of font sizes, allow user-definable foreground and background colors, etc.
What's the best way to apply the CSS styling the user selects/inputs?
Angular provides a number of built-in directives for manipulating CSS styling conditionally/dynamically:
The normal "Angular way" involves tying a model/scope property to a UI element that will accept user input/manipulation (i.e., use ng-model), and then associating that model property to one of the built-in directives mentioned above.
When the user changes the UI, Angular will automatically update the associated elements on the page.
ng-class accepts an "expression" that must evaluate to one of the following:
Assuming your items are displayed using ng-repeat over some array model, and that when the checkbox for an item is checked you want to apply the pending-delete
class:
<div ng-repeat="item in items" ng-class="{'pending-delete': item.checked}">
... HTML to display the item ...
<input type="checkbox" ng-model="item.checked">
</div>
Above, we used ng-class expression type #3 - a map/object of class names to boolean values.
ng-style accepts an "expression" that must evaluate to:
For a contrived example, suppose the user can type in a color name into a texbox for the background color (a jQuery color picker would be much nicer):
<div class="main-body" ng-style="{color: myColor}">
...
<input type="text" ng-model="myColor" placeholder="enter a color name">
The fiddle also contains an example of ng-show and ng-hide. If a checkbox is checked, in addition to the background-color turning pink, some text is shown. If 'red' is entered in the textbox, a div becomes hidden.