如何在继续之前等待 cordova.plugins.sqlitePorter.exportDbToSql 完成？

Question

By using the SQLite Porter Cordova/Phonegap Plugin, i am trying to create a backup file of the application database before continuing to execute the code.

However, i am unable to do so, since it is asyncronous and no matter what i try it always complete before the successFn function executes, even though successFn is sort of a callback.

I have already tried using promisses, await/async to no avail. My last attempt was using promise as shown on the example below.

var successFn = function (sql, count) {
               console.log("Success")
            };
var promise = new Promise(function (resolve, reject) {
    cordova.plugins.sqlitePorter.exportDbToSql(db, {
         successFn: successFn
    })
});
promise.then(
    function () { return true; },
    function (erro) { return false;}
);
console.log("END");

I was expecting the order of the log to be "Success" then "END", but it return "END" then "Success"

Answer 1

Update

As you are using Ionic 1, then you can wrap the function with a promise and use it:

function exportDbToSql() {
  var deferred = $q.defer();
  cordova.plugins.sqlitePorter.exportDbToSql(db, {
    successFn: function(sql, count) { 
      deferred.resolve({sql: sql, count: count}) 
    }
  });
  return deferred.promise;
}

And when you call the function, it will be:

exportDbToSql().then(function(result) {
  console.log(result.sql);
  console.log(result.count);    
});

---

Old answer

If you are using Ionic 2+, then you can follow their documentation here .

Open the command line and enter

ionic cordova plugin add uk.co.workingedge.cordova.plugin.sqliteporter
npm install @ionic-native/sqlite-porter

then you can use it in this way:

import { SQLitePorter } from '@ionic-native/sqlite-porter/ngx';


constructor(private sqlitePorter: SQLitePorter) { }

...

let db = window.openDatabase('Test', '1.0', 'TestDB', 1 * 1024);
// or we can use SQLite plugin
// we will assume that we injected SQLite into this component as sqlite
this.sqlite.create({
  name: 'data.db',
  location: 'default'
})
  .then((db: any) => {
    let dbInstance = db._objectInstance;
    // we can pass db._objectInstance as the database option in all SQLitePorter methods
  });


let sql = 'CREATE TABLE Artist ([Id] PRIMARY KEY, [Title]);' +
           'INSERT INTO Artist(Id,Title) VALUES ("1","Fred");';

this.sqlitePorter.importSqlToDb(db, sql)
  .then(() => console.log('Imported'))
  .catch(e => console.error(e));

In your case, it should work like this:

this.sqlitePorter.exportDbToSql(db)
  .then(() => console.log('success'))
  .catch(() => console.log('error'))