LowlaDB Cordova Plugin

The LowlaDB Cordova plugin provides a native implementation of LowlaDB offering greatly improved performance and scalability on mobile devices. It is fully API-compatible with the javascript implementation and, other than necessary changes required by Cordova, web applications will run unchanged.

The plugin is supported on iOS and Android.

License

The LowlaDB Cordova plugin is available under the MIT license.

Requirements

The plugin is distributed via npm rather than the Cordova Plugin Registry and can be installed using the cordova command line client version 5.0 or above. To develop for iOS, you need a Mac running XCode 6.x or above. The resulting application requires iOS 8.x. To develop for Android, you need Android Studio 1.2. The plugin has not been tested with the older ADT tooling. The resulting application requires Android 4.0.3 or higher.

Creating an iOS Project with LowlaDB

1. Create a new project

cordova create LowlaTest
cd LowlaTest

2. Add iOS support to the project

cordova platform add ios

3. Add the plugin to the project

cordova plugin add lowladb-cordova

4. Update project settings

LowlaDB is packaged as an iOS framework and thus requires iOS 8. To set this, open the project in XCode

open platforms/ios/HelloCordova.xcodeproj

In the General settings for the HelloCordova target, set the Deployment Target to 8.0. Still in the General tab, scroll down until the Embedded Binaries section is visible. Now expand the project tree in the left pane and expand the Frameworks node. Drag LowlaDB.framework to the Embedded Binaries section.

You should now be able to build the project cleanly.

5. Add some test code

Navigate to www/js/index.js in the project tree. Under the line

        receivedElement.setAttribute('style', 'display:block;');

add the code

        var lowla = new LowlaDB();
        var db = lowla.db("mydb");
        db.collectionNames().then(function (names) {
            if (0 == names.length) {
                receivedElement.innerHTML = "LowlaDB is working";
            }
        });

Be sure to save the file!

To copy the test code to the iOS project, return to the command line and enter

cordova prepare ios

6. Build and run

At this point you should be able to build and run the project, either on the simulator or on a device. If everything is working correctly then you should see the usual Cordova startup screen with the message 'LowlaDB is working' in place of the standard 'Device is ready' message.

Creating an Android Project with LowlaDB

1. Create a new project

cordova create LowlaTest
cd LowlaTest

2. Add Android support to the project

cordova platform add android

3. Add the plugin to the project

cordova plugin add lowladb-cordova

4. Import the project into Android Studio

The Android tooling is in the process of migrating from Eclipse to the IntelliJ IDEA-based Android Studio. As such, both Android Studio and Cordova's support for Android are changing rapidly. These instructions apply to Android Studio 1.2.0 and the Cordova commmand line version 5.0.0.

Launch Android Studio and choose File|Import Project and select the LowlaTest/platforms/android folder. Do not select the LowlaTest folder - this will import and build but will not use the new, Gradle-based build.

If you are using older versions of Android Studio or the Cordova CLI, you may get build errors after importing the project into Android Studio as the dependency between the application and CordovaLib has not been set up correctly. The best way to fix this is to upgrade to the latest versions of the tools, but if this isn't an option you can fix the problem by performing a command-line build before importing the project into Android Studio. Specifically:

cd platforms/android
ANDROID_BUILD=gradle ./cordova/build

To be clear, this step is no longer required with Cordova 5.0/Android Studio 1.2.

5. Add some test code

Navigate to www/js/index.js in the project tree. Under the line

        receivedElement.setAttribute('style', 'display:block;');

add the code

        var lowla = new LowlaDB();
        var db = lowla.db("mydb");
        db.collectionNames().then(function (names) {
            if (0 == names.length) {
                receivedElement.innerHTML = "LowlaDB is working";
            }
        });

Be sure to save the file!

To copy the test code to the Android project, return to the command line and enter

cordova prepare android

6. Build and run

At this point you should be able to build and run the project, either on the simulator or on a device. If everything is working correctly then you should see the usual Cordova startup screen with the message 'LowlaDB is working' in place of the standard 'Device is ready' message.

Developing the Plugin

This section is for developers who want to work on the plugin. If you just want to use the plugin in your Cordova application you don't need to know anything anything described below.

Setting up the Development Environment

The Cordova plugin is built on top of the lowladb-objc and lowladb-android-lib projects which in turn build on liblowladb. Although those libraries publish their artifacts via standard library mechanisms (CocoaPods and Android aar files, respectively) it is hard to consume those formats in Cordova. Instead the necessary files need to to be copied from those projects into the plugin's src directory.

You can collect all the necessary source locally with the following commands.

mkdir lowla-dev
cd lowla-dev
git clone https://github.com/lowla/liblowladb.git
git clone https://github.com/lowla/lowladb-objc.git
git clone https://github.com/lowla/lowladb-android-lib.git
git clone https://github.com/lowla/lowladb-cordova.git

The next step is to create a test project. The plugin contains a test suite as a sub-plugin and any new development should start by adding to the test suite.

cordova create test
cd test
cordova platform add ios android
cordova plugin add ../lowladb-cordova
cordova plugin add ../lowladb-cordova/tests

Note that the test project pulls the lowladb plugin from a local directory rather than the plugin repository.

Finally follow step 4 above which describes how to import your project into XCode or Android Studio and build.

The Development Workflow

Changes need to flow through from the lowest level (liblowladb) to the highest (lowladb-cordova). So in the most complex case, a new feature will require

• Adding new failing tests to lowladb-cordova/tests/tests.js
• Adding code and tests to liblowladb and verifying that the tests pass on OSX/iOS.
• Adding the necessary wrappers and tests to lowladb-objc and lowladb-android-lib.
• Rebuilding the lowladb-objc framework and copying it over to lowladb-cordova/src/ios/LowlaDB.framework
• Adding any new wrappers to lowladb-cordova/src/ios/LDBCordova.m
• Rebuilding the lowladb-android-lib project and copying the .so and .java files to lowladb-cordova/src/android/lowladb-android
• [Optional: If the above step created any new .java files, they need to be added to lowladb-cordova/plugin.xml]
• Adding any new wrappers to lowladb-cordova/src/android/LDBCordova.java
• Adding any new public APIs/fixes to lowladb-cordova/www/LowlaDB-Cordova.js

Once those changes have been made, you need to redeploy the plugins

cordova plugin remove io.lowla.lowladb
cordova plugin remove io.lowla.lowladb.tests
cordova plugin add ../lowladb-cordova
cordova plugin add ../lowladb-cordova/tests

On iOS, this seems to break some of the project configuration and you may have to re-add LowlaDB.framework to the embedded binaries and re-assign LDBCordova.m to the application target.