angular.js/src/ng/directive/ngPluralize.js
Shyam Seshadri 2c6aa4c300 fix(*): name all anonymous watch functions in Angular
This will allow us to see function names in Batarang and debugger.

Closes #1119
2012-09-11 16:39:46 -07:00

207 lines
9.7 KiB
JavaScript

'use strict';
/**
* @ngdoc directive
* @name ng.directive:ngPluralize
* @restrict EA
*
* @description
* # Overview
* `ngPluralize` is a directive that displays messages according to en-US localization rules.
* These rules are bundled with angular.js and the rules can be overridden
* (see {@link guide/i18n Angular i18n} dev guide). You configure ngPluralize directive
* by specifying the mappings between
* {@link http://unicode.org/repos/cldr-tmp/trunk/diff/supplemental/language_plural_rules.html
* plural categories} and the strings to be displayed.
*
* # Plural categories and explicit number rules
* There are two
* {@link http://unicode.org/repos/cldr-tmp/trunk/diff/supplemental/language_plural_rules.html
* plural categories} in Angular's default en-US locale: "one" and "other".
*
* While a pural category may match many numbers (for example, in en-US locale, "other" can match
* any number that is not 1), an explicit number rule can only match one number. For example, the
* explicit number rule for "3" matches the number 3. You will see the use of plural categories
* and explicit number rules throughout later parts of this documentation.
*
* # Configuring ngPluralize
* You configure ngPluralize by providing 2 attributes: `count` and `when`.
* You can also provide an optional attribute, `offset`.
*
* The value of the `count` attribute can be either a string or an {@link guide/expression
* Angular expression}; these are evaluated on the current scope for its bound value.
*
* The `when` attribute specifies the mappings between plural categories and the actual
* string to be displayed. The value of the attribute should be a JSON object so that Angular
* can interpret it correctly.
*
* The following example shows how to configure ngPluralize:
*
* <pre>
* <ng-pluralize count="personCount"
when="{'0': 'Nobody is viewing.',
* 'one': '1 person is viewing.',
* 'other': '{} people are viewing.'}">
* </ng-pluralize>
*</pre>
*
* In the example, `"0: Nobody is viewing."` is an explicit number rule. If you did not
* specify this rule, 0 would be matched to the "other" category and "0 people are viewing"
* would be shown instead of "Nobody is viewing". You can specify an explicit number rule for
* other numbers, for example 12, so that instead of showing "12 people are viewing", you can
* show "a dozen people are viewing".
*
* You can use a set of closed braces(`{}`) as a placeholder for the number that you want substituted
* into pluralized strings. In the previous example, Angular will replace `{}` with
* <span ng-non-bindable>`{{personCount}}`</span>. The closed braces `{}` is a placeholder
* for <span ng-non-bindable>{{numberExpression}}</span>.
*
* # Configuring ngPluralize with offset
* The `offset` attribute allows further customization of pluralized text, which can result in
* a better user experience. For example, instead of the message "4 people are viewing this document",
* you might display "John, Kate and 2 others are viewing this document".
* The offset attribute allows you to offset a number by any desired value.
* Let's take a look at an example:
*
* <pre>
* <ng-pluralize count="personCount" offset=2
* when="{'0': 'Nobody is viewing.',
* '1': '{{person1}} is viewing.',
* '2': '{{person1}} and {{person2}} are viewing.',
* 'one': '{{person1}}, {{person2}} and one other person are viewing.',
* 'other': '{{person1}}, {{person2}} and {} other people are viewing.'}">
* </ng-pluralize>
* </pre>
*
* Notice that we are still using two plural categories(one, other), but we added
* three explicit number rules 0, 1 and 2.
* When one person, perhaps John, views the document, "John is viewing" will be shown.
* When three people view the document, no explicit number rule is found, so
* an offset of 2 is taken off 3, and Angular uses 1 to decide the plural category.
* In this case, plural category 'one' is matched and "John, Marry and one other person are viewing"
* is shown.
*
* Note that when you specify offsets, you must provide explicit number rules for
* numbers from 0 up to and including the offset. If you use an offset of 3, for example,
* you must provide explicit number rules for 0, 1, 2 and 3. You must also provide plural strings for
* plural categories "one" and "other".
*
* @param {string|expression} count The variable to be bounded to.
* @param {string} when The mapping between plural category to its correspoding strings.
* @param {number=} offset Offset to deduct from the total number.
*
* @example
<doc:example>
<doc:source>
<script>
function Ctrl($scope) {
$scope.person1 = 'Igor';
$scope.person2 = 'Misko';
$scope.personCount = 1;
}
</script>
<div ng-controller="Ctrl">
Person 1:<input type="text" ng-model="person1" value="Igor" /><br/>
Person 2:<input type="text" ng-model="person2" value="Misko" /><br/>
Number of People:<input type="text" ng-model="personCount" value="1" /><br/>
<!--- Example with simple pluralization rules for en locale --->
Without Offset:
<ng-pluralize count="personCount"
when="{'0': 'Nobody is viewing.',
'one': '1 person is viewing.',
'other': '{} people are viewing.'}">
</ng-pluralize><br>
<!--- Example with offset --->
With Offset(2):
<ng-pluralize count="personCount" offset=2
when="{'0': 'Nobody is viewing.',
'1': '{{person1}} is viewing.',
'2': '{{person1}} and {{person2}} are viewing.',
'one': '{{person1}}, {{person2}} and one other person are viewing.',
'other': '{{person1}}, {{person2}} and {} other people are viewing.'}">
</ng-pluralize>
</div>
</doc:source>
<doc:scenario>
it('should show correct pluralized string', function() {
expect(element('.doc-example-live ng-pluralize:first').text()).
toBe('1 person is viewing.');
expect(element('.doc-example-live ng-pluralize:last').text()).
toBe('Igor is viewing.');
using('.doc-example-live').input('personCount').enter('0');
expect(element('.doc-example-live ng-pluralize:first').text()).
toBe('Nobody is viewing.');
expect(element('.doc-example-live ng-pluralize:last').text()).
toBe('Nobody is viewing.');
using('.doc-example-live').input('personCount').enter('2');
expect(element('.doc-example-live ng-pluralize:first').text()).
toBe('2 people are viewing.');
expect(element('.doc-example-live ng-pluralize:last').text()).
toBe('Igor and Misko are viewing.');
using('.doc-example-live').input('personCount').enter('3');
expect(element('.doc-example-live ng-pluralize:first').text()).
toBe('3 people are viewing.');
expect(element('.doc-example-live ng-pluralize:last').text()).
toBe('Igor, Misko and one other person are viewing.');
using('.doc-example-live').input('personCount').enter('4');
expect(element('.doc-example-live ng-pluralize:first').text()).
toBe('4 people are viewing.');
expect(element('.doc-example-live ng-pluralize:last').text()).
toBe('Igor, Misko and 2 other people are viewing.');
});
it('should show data-binded names', function() {
using('.doc-example-live').input('personCount').enter('4');
expect(element('.doc-example-live ng-pluralize:last').text()).
toBe('Igor, Misko and 2 other people are viewing.');
using('.doc-example-live').input('person1').enter('Di');
using('.doc-example-live').input('person2').enter('Vojta');
expect(element('.doc-example-live ng-pluralize:last').text()).
toBe('Di, Vojta and 2 other people are viewing.');
});
</doc:scenario>
</doc:example>
*/
var ngPluralizeDirective = ['$locale', '$interpolate', function($locale, $interpolate) {
var BRACE = /{}/g;
return {
restrict: 'EA',
link: function(scope, element, attr) {
var numberExp = attr.count,
whenExp = element.attr(attr.$attr.when), // this is because we have {{}} in attrs
offset = attr.offset || 0,
whens = scope.$eval(whenExp),
whensExpFns = {},
startSymbol = $interpolate.startSymbol(),
endSymbol = $interpolate.endSymbol();
forEach(whens, function(expression, key) {
whensExpFns[key] =
$interpolate(expression.replace(BRACE, startSymbol + numberExp + '-' +
offset + endSymbol));
});
scope.$watch(function ngPluralizeWatch() {
var value = parseFloat(scope.$eval(numberExp));
if (!isNaN(value)) {
//if explicit number rule such as 1, 2, 3... is defined, just use it. Otherwise,
//check it against pluralization rules in $locale service
if (!whens[value]) value = $locale.pluralCat(value - offset);
return whensExpFns[value](scope, element, true);
} else {
return '';
}
}, function ngPluralizeWatchAction(newVal) {
element.text(newVal);
});
}
};
}];