Question

参考这个答案How do I return the response from an asynchronous call?我怎么能在我的secanrio中实现这个。

我正在尝试使用cordova sqlite插件使用sqlite进行缓存，但我的问题是我的控制器在我的工厂完成执行之前执行。我正在粘贴我的控制器代码和我的工厂代码。我知道执行的顺序已经提醒了。我理想的警报序列是1,2,3,4,5,6但是当我执行代码时，我得到的警报序列如1,5,6,2,3,4。我正在粘贴下面的控制器和工厂代码。

angular.module('foo').controller('PriceListController',["$scope","$http","$stateParams","CURD","$q","DB", function($scope,$http,$stateParams,CURD,$q,DB) {

$scope.brand_id=Number($stateParams.id);
$scope.process=true;
$scope.pricelists=[];    
$scope.getBrandDocs= function(){
    var parameters=new Array(2);
    parameters[0]=$scope.brand_id
    parameters[1]=1;
    CURD.exc_query("select * from brand_docs where brand_id=? AND type=?",parameters)
        .then(function(price_lists) {
            alert("2");
            $scope.inter_pricelist=price_lists;
            console.log("Records from query call:"+JSON.stringify( $scope.inter_pricelist)); 

            $scope.deferred = $q.defer();    
            if ($scope.inter_pricelist){
                console.log("Found data inside cache", JSON.stringify($scope.inter_pricelist));
                $scope.deferred.resolve($scope.inter_pricelist);
                // alert(JSON.stringify( $scope.inter_pricelist));
                alert("3");

            } 
            else{
                $http.get('http://foo.com?brand='+ $scope.brand_id +'&type=price_list')
                .success(function(data) {
                    //alert("http call");
                    console.log("Received data via HTTP",JSON.stringify(data));
                    angular.forEach(data.data.info, function(value, key) {
                        var sql = "INSERT OR REPLACE INTO brand_docs(id, brand_id, name, file_url,type) VALUES (?, ?, ?, ?, ?)"; 
                        var parameters=new Array(5);
                        parameters[0]=value.id;
                        parameters[1]=value.brand_id;
                        parameters[2]=value.name;
                        parameters[3]=value.file_url;
                        parameters[4]=value.type;    
                        var result=DB.query(sql,parameters);
                    });

                    $scope.deferred.resolve(data.data.info);

                })
                .error(function() {
                    console.log("Error while making HTTP call.");
                    $scope.deferred.reject();
                });
        }

        return ($scope.deferred.promise).then(function(pricelists){
        alert("4");    
            return pricelists;
        },function(){});

    },function(){});  
  alert("5");  
};

$scope.pricelists=$scope.getBrandDocs();
alert("6"); 
}]);

//这是我粘贴的工厂代码

angular.module('foo').factory('DB', function($q, DB_CONFIG,$cordovaSQLite) {
    var self = this;
    self.db = null;

    self.init = function() {
        try{ 
            self.db =  window.sqlitePlugin.openDatabase(DB_CONFIG.name, '1.0', 'database', -1);
            angular.forEach(DB_CONFIG.tables, function(table) {
                var columns = [];
                angular.forEach(table.columns, function(column) {
                    columns.push(column.name + ' ' + column.type);
                });
                var query = 'CREATE TABLE IF NOT EXISTS ' + table.name + ' (' + columns.join(',') + ')';
                self.query(query);
                console.log('Table ' + table.name + ' initialized');
            });
        }
        catch(err){
        }

    };

    self.query = function(query, bindings) {
        bindings = typeof bindings !== 'undefined' ? bindings : [];
        console.log("Query:"+query+" bindings:"+ bindings);
        var deferred = $q.defer();

        self.db.transaction(function(transaction) {
            transaction.executeSql(query, bindings, function(transaction, result) {
                console.log("Query sucessfull :"+ query);
                console.log("Result of Query:"+ JSON.stringify(result));
                deferred.resolve(result);

            }, function(transaction, error) {
                console.log("Error:"+ JSON.stringify(error));
                deferred.reject(error);
            });
        });

        return deferred.promise;
    };

    self.fetchAll = function(result) {
        var output = [];

        for (var i = 0; i < result.rows.length; i++) {
            output.push(result.rows.item(i));

        }
         //console.log("RECORDS:" +JSON.stringify(output));
        return output;
    };

    self.fetch = function(result) {
        return result.rows.item(0);
    };

    return self;
})
.factory('CURD', function(DB) {
    var self = this;

    self.all = function(table_name) {
        return DB.query('SELECT * FROM '+table_name)
        .then(function(result){
            return DB.fetchAll(result);
        });
    };

    self.exc_query = function(query,parameters) {
        return DB.query(query,parameters)
        .then(function(result){
            return DB.fetchAll(result);
        });
    };

    self.getById = function(id,table_name) {
        return DB.query('SELECT * FROM '+table_name +' WHERE id = ?', [id])
        .then(function(result){
            return DB.fetch(result);
        });
    };

    return self;
});

Answer 1

查询以异步方式完成。我的意思是，当你调用CURD.exec_query（）时，查询排队，一旦排队，你的方法继续执行＆＃34; return（$ scope.deferred.promise）.then（function（ pricelists）{＆＃34;。这就是为什么4,5,6出现在2和3之前的原因。一旦查询完成，再次，异步，＆＃34; .then（）＆＃34;方法是被叫，这是2和3被警告的时候。

请注意，getBrandDocs（）将返回BEFORE，然后调用.then（）方法。你可以做的是让你的.then（）方法发出一个在调用代码中异步拾取的事件，然后执行4步，5步和6步。

控制器在factroy给出结果之前执行

1 个答案: