angularjs上传多张图片并预览

/*
* 多图片上传及预览指令(需指定图片类名)
*
*/

angular.module('routerModule').directive('fileModel', ['$parse', 'fileReader', function($parse, fileReader) {
return {
restrict:'A',
link:function(scope, element, attrs, ngModel) {
var model = $parse(attrs.fileModel);
var modelSetter = model.assign;
var imgviewID = attrs["imgViewId"];
var imgView = angular.element(document.querySelector("."+imgviewID));
element.bind('change', function(event) {
scope.$apply(function() {
modelSetter(scope, element[0].files[0]);
});
//附件预览
scope.file = (event.srcElement || event.target).files[0];
fileReader.readAsDataUrl(scope.file, scope).then(function(result) {
imgView.attr("src",result);
});
});
}
}
}]);

angular.module('routerModule').factory('fileReader', ["$q", "$log", function($q, $log) {
var onLoad = function(reader, deferred, scope) {
return function() {
scope.$apply(function() {
deferred.resolve(reader.result);
});
}
}

var onError = function(reader, deferred, scope) {
return function() {
scope.$apply(function() {
deferred.reject(reader.result);
});
};
};

var getReader = function(deferred, scope) {
var reader = new FileReader();
reader.onload = onLoad(reader, deferred, scope);
reader.onerror = onError(reader, deferred, scope);
return reader;
};

var readAsDataURL = function(file, scope) {
var deferred = $q.defer();
var reader = getReader(deferred, scope);
reader.readAsDataURL(file);
return deferred.promise;
}
return {
readAsDataUrl: readAsDataURL
};
}
]);

<section class="infogroup">
    <h4>法人证件</h4>
    <div class="row relatedCard">
        <div class="col-md-4 txtcenter">
            <p>身份证正面</p>
            <div><img ng-src="showImg/{{dealer.idCardFace}}" class="idCardFace" enlarge-pic/></div>
            <span class="btn btn-file btn btn-xs btn-primary btn-editable picEdit"><i class="fa fa-edit"></i> 点击编辑
                 <input type="file" file-model="idCardFace" img-view-id="idCardFace" />
            </span> 
        </div>
        <div class="col-md-4 txtcenter">
            <p>身份证反面</p>
            <div><img ng-src="showImg/{{dealer.idCardBack}}" class="idCardBack" enlarge-pic/></div>
            <span class="btn btn-file btn btn-xs btn-primary btn-editable picEdit"><i class="fa fa-edit"></i> 点击编辑
                 <input type="file" file-model="idCardBack" img-view-id="idCardBack" />
            </span> 
        </div>                                      
    </div>
</section>

$scope.postData = {
dealerId: $scope.dealer.dealerId,
companyName: $scope.dealer.companyName,
companySize: $scope.dealer.companySize,
idCardFace: angular.element(document.querySelector(".idCardFace"))[0].src,
idCardBack: angular.element(document.querySelector(".idCardBack"))[0].src
};
$http.post('updateDealerCertificate',$scope.postData).success(function(data){
<!-- 成功执行代码 -->
});