Javascript AngularJS自定义指令类似于ng要求
所以我已经花了大约4个小时在这上面了。Javascript AngularJS自定义指令类似于ng要求,javascript,angularjs,Javascript,Angularjs,所以我已经花了大约4个小时在这上面了。 我试图实现的是一个自定义指令,类似于ng required,它有一个输入并进行验证。 以下是ng所需的代码 var requiredDirective = function() { return { restrict: 'A', require: '?ngModel', link: function(scope, elm, attr, ctrl) { if (!ctrl) return; attr.re
我试图实现的是一个自定义指令,类似于ng required,它有一个输入并进行验证。
以下是ng所需的代码
var requiredDirective = function() {
return {
restrict: 'A',
require: '?ngModel',
link: function(scope, elm, attr, ctrl) {
if (!ctrl) return;
attr.required = true; // force truthy in case we are on non input element
ctrl.$validators.required = function(modelValue, viewValue) {
return !attr.required || !ctrl.$isEmpty(viewValue);
};
attr.$observe('required', function() {
ctrl.$validate();
});
}
};
};
我知道当所需属性更改其值时,我们将再次进行验证。说如果你有
<input
ng-model="sor.seal"
ng-model-options="{ updateOn : 'default blur' }"
class="form-control"
ng-required="sor.sealUwatType=='SEAL'"
type="text"
placeholder="Enter a SEAL/UWAT ID"
id="seal"
name="seal"
/>
当ng required表达式为true时,如何添加属性required=“required”?当ng required表达式为false时,它如何删除属性?Angular在所有布尔属性等价项上创建内部属性,如
ng required、ng checked、ng disabled
等
var BOOLEAN_ATTR = {};
forEach('multiple,selected,checked,disabled,readOnly,required,open'.split(','), function(value) {
BOOLEAN_ATTR[lowercase(value)] = value;
});
forEach(BOOLEAN_ATTR, function(propName, attrName) {
// binding to multiple is not supported
if (propName == "multiple") return;
function defaultLinkFn(scope, element, attr) {
scope.$watch(attr[normalized], function ngBooleanAttrWatchAction(value) {
attr.$set(attrName, !!value);
});
}
var normalized = directiveNormalize('ng-' + attrName);
var linkFn = defaultLinkFn;
if (propName === 'checked') {
linkFn = function(scope, element, attr) {
// ensuring ngChecked doesn't interfere with ngModel when both are set on the same input
if (attr.ngModel !== attr[normalized]) {
defaultLinkFn(scope, element, attr);
}
};
}
ngAttributeAliasDirectives[normalized] = function() {
return {
restrict: 'A',
priority: 100,
link: linkFn
};
};
});
注册在这些上的通用链接函数执行属性的通用切换
var BOOLEAN_ATTR = {};
forEach('multiple,selected,checked,disabled,readOnly,required,open'.split(','), function(value) {
BOOLEAN_ATTR[lowercase(value)] = value;
});
forEach(BOOLEAN_ATTR, function(propName, attrName) {
// binding to multiple is not supported
if (propName == "multiple") return;
function defaultLinkFn(scope, element, attr) {
scope.$watch(attr[normalized], function ngBooleanAttrWatchAction(value) {
attr.$set(attrName, !!value);
});
}
var normalized = directiveNormalize('ng-' + attrName);
var linkFn = defaultLinkFn;
if (propName === 'checked') {
linkFn = function(scope, element, attr) {
// ensuring ngChecked doesn't interfere with ngModel when both are set on the same input
if (attr.ngModel !== attr[normalized]) {
defaultLinkFn(scope, element, attr);
}
};
}
ngAttributeAliasDirectives[normalized] = function() {
return {
restrict: 'A',
priority: 100,
link: linkFn
};
};
});
因此基本上,ng required
添加了属性required
,该属性执行以下操作:
您可以通过输出ngRequired
指令实际包含的内容来验证这一点,它包含两个指令配置,一个具有优先级100(在ng模型之前运行),用于设置/重置其所在元素上的属性,另一个具有ng模型和验证器的验证挂钩
.config(function($provide) {
$provide.decorator('ngRequiredDirective', function($delegate) {
console.log($delegate); //Check the console on the configuration you will see array of 2 configurations
return $delegate;
})
});
这相当于为同一个指令选择器创建两个配置,例如:
angular.module('app',[]).directive('myDir',function(){
返回{
限制:“A”,
链接:函数(){
控制台日志(“A”);
}
}
}).directive('myDir',function(){
返回{
限制:“A”,
链接:函数(){
控制台日志(“B”);
}
}
}).config(函数($provide){
$provide.decorator('myDirDirective',函数($delegate){
log($delegate);//检查控制台上的配置,您将看到2个配置的数组
返回$delegate;
})
});代码>