在一个项目中需要一个用来输入分钟数和秒数的控件，然而调查了一些开源项目后并未发现合适的控件。在Angular Bootstrap UI中有一个类似的控件TimePicker，但是它并没有深入到分钟和秒的精度。
因此，决定参考它的源码然后自己进行实现。
最终的效果如下：
首先是该directive的定义：
app.directive('minuteSecondPicker', function() {
return {
restrict: 'EA',
require: ['minuteSecondPicker', '?^ngModel'],
controller: 'minuteSecondPickerController',
replace: true,
scope: {
validity: '='
},
templateUrl: 'partials/directives/minuteSecondPicker.html',
link: function(scope, element, attrs, ctrls) {
var minuteSecondPickerCtrl = ctrls[0],
ngModelCtrl = ctrls[1];
if(ngModelCtrl) {
minuteSecondPickerCtrl.init(ngModelCtrl, element.find('input'));
}
}
};
});
在以上的link函数中，ctrls是一个数组： ctrls[0]是定义在本directive上的controller实例，ctrls[1]是ngModelCtrl，即ng-model对应的controller实例。这个顺序实际上是通过require: ['minuteSecondPicker', '?^ngModel']定义的。
注意到第一个依赖就是directive本身的名字，此时会将该directive中controller声明的对应实例传入。第二个依赖的写法有些奇怪："?^ngModel"，?的含义是即使没有找到该依赖，也不要抛出异常，即该依赖是一个可选项。^的含义是查找父元素的controller。
然后，定义该directive中用到的一些默认设置，通过constant directive实现：
app.constant('minuteSecondPickerConfig', {
minuteStep: 1,
secondStep: 1,
readonlyInput: false,
mousewheel: true
});
紧接着是directive对应的controller，它的声明如下：
app.controller('minuteSecondPickerController', ['$scope', '$attrs', '$parse', 'minuteSecondPickerConfig',
function($scope, $attrs, $parse, minuteSecondPickerConfig) {
...
}]);
在directive的link函数中，调用了此controller的init方法：
this.init = function(ngModelCtrl_, inputs) {
ngModelCtrl = ngModelCtrl_;
ngModelCtrl.$render = this.render;
var minutesInputEl = inputs.eq(0),
secondsInputEl = inputs.eq(1);
var mousewheel = angular.isDefined($attrs.mousewheel) ?
$scope.$parent.$eval($attrs.mousewheel) : minuteSecondPickerConfig.mousewheel;
if(mousewheel) {
this.setupMousewheelEvents(minutesInputEl, secondsInputEl);
}
$scope.readonlyInput = angular.isDefined($attrs.readonlyInput) ?
$scope.$parent.$eval($attrs.readonlyInput) : minuteSecondPickerConfig.readonlyInput;
this.setupInputEvents(minutesInputEl, secondsInputEl);
};
init方法接受的第二个参数是inputs，在link函数中传入的是：element.find('input')。 所以第一个输入框用来输入分钟，第二个输入框用来输入秒。
然后，检查是否覆盖了mousewheel属性，如果没有覆盖则使用在constant中设置的默认mousewheel，并进行相关设置如下：
// respond on mousewheel spin
this.setupMousewheelEvents = function(minutesInputEl, secondsInputEl) {
var isScrollingUp = function(e) {
if(e.originalEvent) {
e = e.originalEvent;
}
// pick correct delta variable depending on event
var delta = (e.wheelData) ? e.wheelData : -e.deltaY;
return (e.detail || delta > 0);
};
minutesInputEl.bind('mousewheel wheel', function(e) {
$scope.$apply((isScrollingUp(e)) ? $scope.incrementMinutes() : $scope.decrementMinutes());
e.preventDefault();
});
secondsInputEl.bind('mousewheel wheel', function(e) {
$scope.$apply((isScrollingUp(e)) ? $scope.incrementSeconds() : $scope.decrementSeconds());
e.preventDefault();
});
};
init方法最后会对inputs本身进行一些设置：
// respond on direct input
this.setupInputEvents = function(minutesInputEl, secondsInputEl) {
if($scope.readonlyInput) {
$scope.updateMinutes = angular.noop;
$scope.updateSeconds = angular.noop;
return;
}
var invalidate = function(invalidMinutes, invalidSeconds) {
ngModelCtrl.$setViewValue(null);
ngModelCtrl.$setValidity('time', false);
$scope.validity = false;
if(angular.isDefined(invalidMinutes)) {
$scope.invalidMinutes = invalidMinutes;
}
if(angular.isDefined(invalidSeconds)) {
$scope.invalidSeconds = invalidSeconds;
}
};
$scope.updateMinutes = function() {
var minutes = getMinutesFromTemplate();
if(angular.isDefined(minutes)) {
selected.minutes = minutes;
refresh('m');
} else {
invalidate(true);
}
};
minutesInputEl.bind('blur', function(e) {
if(!$scope.invalidMinutes && $scope.minutes < 10) {
$scope.$apply(function() {
$scope.minutes = pad($scope.minutes);
});
}
});
$scope.updateSeconds = function() {
var seconds = getSecondsFromTemplate();
if(angular.isDefined(seconds)) {
selected.seconds = seconds;
refresh('s');
} else {
invalidate(undefined, true);
}
};
secondsInputEl.bind('blur', function(e) {
if(!$scope.invalidSeconds && $scope.seconds < 10) {
$scope.$apply(function() {
$scope.seconds = pad($scope.seconds);
});
}
});
};
此方法中，声明了用于设置输入非法的invalidate函数，它会在scope中暴露一个validity = false属性让页面有机会做出合适的反应。
如果用户使用了一个变量来表示minuteStep或者secondStep，那么还需要设置相应的watchers：
var minuteStep = minuteSecondPickerConfig.minuteStep;
if($attrs.minuteStep) {
$scope.parent.$watch($parse($attrs.minuteStep), function(value) {
minuteStep = parseInt(value, 10);
});
}
var secondStep = minuteSecondPickerConfig.secondStep;
if($attrs.secondStep) {
$scope.parent.$watch($parse($attrs.secondStep), function(value) {
secondStep = parseInt(value, 10);
});
}
完整的directive实现代码如下：
var app = angular.module("minuteSecondPickerDemo");
app.directive('minuteSecondPicker', function() {
return {
restrict: 'EA',
require: ['minuteSecondPicker', '?^ngModel'],
controller: 'minuteSecondPickerController',
replace: true,
scope: {
validity: '='
},
templateUrl: 'partials/directives/minuteSecondPicker.html',
link: function(scope, element, attrs, ctrls) {
var minuteSecondPickerCtrl = ctrls[0],
ngModelCtrl = ctrls[1];
if(ngModelCtrl) {
minuteSecondPickerCtrl.init(ngModelCtrl, element.find('input'));
}
}
};
});
app.constant('minuteSecondPickerConfig', {
minuteStep: 1,
secondStep: 1,
readonlyInput: false,
mousewheel: true
});
app.controller('minuteSecondPickerController', ['$scope', '$attrs', '$parse', 'minuteSecondPickerConfig',
function($scope, $attrs, $parse, minuteSecondPickerConfig) {
var selected = {
minutes: 0,
seconds: 0
},
ngModelCtrl = {
$setViewValue: angular.noop
};
this.init = function(ngModelCtrl_, inputs) {
ngModelCtrl = ngModelCtrl_;
ngModelCtrl.$render = this.render;
var minutesInputEl = inputs.eq(0),
secondsInputEl = inputs.eq(1);
var mousewheel = angular.isDefined($attrs.mousewheel) ?
$scope.$parent.$eval($attrs.mousewheel) : minuteSecondPickerConfig.mousewheel;
if(mousewheel) {
this.setupMousewheelEvents(minutesInputEl, secondsInputEl);
}
$scope.readonlyInput = angular.isDefined($attrs.readonlyInput) ?
$scope.$parent.$eval($attrs.readonlyInput) : minuteSecondPickerConfig.readonlyInput;
this.setupInputEvents(minutesInputEl, secondsInputEl);
};
var minuteStep = minuteSecondPickerConfig.minuteStep;
if($attrs.minuteStep) {
$scope.parent.$watch($parse($attrs.minuteStep), function(value) {
minuteStep = parseInt(value, 10);
});
}
var secondStep = minuteSecondPickerConfig.secondStep;
if($attrs.secondStep) {
$scope.parent.$watch($parse($attrs.secondStep), function(value) {
secondStep = parseInt(value, 10);
});
}
// respond on mousewheel spin
this.setupMousewheelEvents = function(minutesInputEl, secondsInputEl) {
var isScrollingUp = function(e) {
if(e.originalEvent) {
e = e.originalEvent;
}
// pick correct delta variable depending on event
var delta = (e.wheelData) ? e.wheelData : -e.deltaY;
return (e.detail || delta > 0);
};
minutesInputEl.bind('mousewheel wheel', function(e) {
$scope.$apply((isScrollingUp(e)) ? $scope.incrementMinutes() : $scope.decrementMinutes());
e.preventDefault();
});
secondsInputEl.bind('mousewheel wheel', function(e) {
$scope.$apply((isScrollingUp(e)) ? $scope.incrementSeconds() : $scope.decrementSeconds());
e.preventDefault();
});
};
// respond on direct input
this.setupInputEvents = function(minutesInputEl, secondsInputEl) {
if($scope.readonlyInput) {
$scope.updateMinutes = angular.noop;
$scope.updateSeconds = angular.noop;
return;
}
var invalidate = function(invalidMinutes, invalidSeconds) {
ngModelCtrl.$setViewValue(null);
ngModelCtrl.$setValidity('time', false);
$scope.validity = false;
if(angular.isDefined(invalidMinutes)) {
$scope.invalidMinutes = invalidMinutes;
}
if(angular.isDefined(invalidSeconds)) {
$scope.invalidSeconds = invalidSeconds;
}
};
$scope.updateMinutes = function() {
var minutes = getMinutesFromTemplate();
if(angular.isDefined(minutes)) {
selected.minutes = minutes;
refresh('m');
} else {
invalidate(true);
}
};
minutesInputEl.bind('blur', function(e) {
if(!$scope.invalidMinutes && $scope.minutes < 10) {
$scope.$apply(function() {
$scope.minutes = pad($scope.minutes);
});
}
});
$scope.updateSeconds = function() {
var seconds = getSecondsFromTemplate();
if(angular.isDefined(seconds)) {
selected.seconds = seconds;
refresh('s');
} else {
invalidate(undefined, true);
}
};
secondsInputEl.bind('blur', function(e) {
if(!$scope.invalidSeconds && $scope.seconds < 10) {
$scope.$apply(function() {
$scope.seconds = pad($scope.seconds);
});
}
});
};
this.render = function() {
var time = ngModelCtrl.$modelValue ? {
minutes: ngModelCtrl.$modelValue.minutes,
seconds: ngModelCtrl.$modelValue.seconds
} : null;
// adjust the time for invalid value at first time
if(time.minutes < 0) {
time.minutes = 0;
}
if(time.seconds < 0) {
time.seconds = 0;
}
var totalSeconds = time.minutes * 60 + time.seconds;
time = {
minutes: Math.floor(totalSeconds / 60),
seconds: totalSeconds % 60
};
if(time) {
selected = time;
makeValid();
updateTemplate();
}
};
// call internally when the model is valid
function refresh(keyboardChange) {
makeValid();
ngModelCtrl.$setViewValue({
minutes: selected.minutes,
seconds: selected.seconds
});
updateTemplate(keyboardChange);
}
function makeValid() {
ngModelCtrl.$setValidity('time', true);
$scope.validity = true;
$scope.invalidMinutes = false;
$scope.invalidSeconds = false;
}
function updateTemplate(keyboardChange) {
var minutes = selected.minutes,
seconds = selected.seconds;
$scope.minutes = keyboardChange === 'm' ? minutes : pad(minutes);
$scope.seconds = keyboardChange === 's' ? seconds : pad(seconds);
}
function pad(value) {
return ( angular.isDefined(value) && value.toString().length < 2 ) ? '0' + value : value;
}
function getMinutesFromTemplate() {
var minutes = parseInt($scope.minutes, 10);
return (minutes >= 0) ? minutes : undefined;
}
function getSecondsFromTemplate() {
var seconds = parseInt($scope.seconds, 10);
if(seconds >= 60) {
seconds = 59;
}
return (seconds >= 0) ? seconds : undefined;
}
$scope.incrementMinutes = function() {
addSeconds(minuteStep * 60);
};
$scope.decrementMinutes = function() {
addSeconds(-minuteStep * 60);
};
$scope.incrementSeconds = function() {
addSeconds(secondStep);
};
$scope.decrementSeconds = function() {
addSeconds(-secondStep);
};
function addSeconds(seconds) {
var newSeconds = selected.minutes * 60 + selected.seconds + seconds;
if(newSeconds < 0) {
newSeconds = 0;
}
selected = {
minutes: Math.floor(newSeconds / 60),
seconds: newSeconds % 60
};
refresh();
}
$scope.previewTime = function(minutes, seconds) {
var totalSeconds = parseInt(minutes, 10) * 60 + parseInt(seconds, 10),
hh = pad(Math.floor(totalSeconds / 3600)),
mm = pad(minutes % 60),
ss = pad(seconds);
return hh + ':' + mm + ':' + ss;
};
}]);
对应的Template实现：
| : | {{ previewTime(minutes, seconds) }} | |||
测试代码(即前面截图dialog的源代码)：
Highlight on {{ movieName }}
Start Time:
End Time:
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持全福编程网。
