RealmExpressions

Build strings expressions and transform it to Realm objects.

Installation

1. Add it in your root build.gradle at the end of repositories

  allprojects {
      repositories {
        ...
        maven { url 'https://jitpack.io' }
      }
    }

2. Add the dependency

  dependencies {
      implementation 'com.github.javierpe:RealmExpressions:1.0.3'
  }

Usage

1. RealmExpression instance

RealmExpression.init(context);

2. Build engine

 RealmExpression engine = new RealmExpression.Builder().addExpression(KEY, EXPRESSION);

3. Add template (Optional)

 RealmExpression engine = new RealmExpression.Builder()
                 .addExpression(KEY, EXPRESSION)
                 .withTemplate("Result: KEY");

Evaluation

1. Synchronous evaluation

Object result = engine.evaluateSync();

2. Asynchronous evaluation

engine.evaluateAsync(new OnEvaluationListener() {
    @Override
    public void onEvaluationResult(String template, Object result) {
        System.out.println("Template: " + template);
        System.out.println("Result: " + result);
        System.out.println("* * * * * * * * * * *");
    }

    @Override
    public void onExpressionResult(String key, String expression, Object result) {
        System.out.println("Key: " + key);
        System.out.println("Expression: " + expression);
        System.out.println("Result: " + result);
        System.out.println("= = = = = = = = = = = =");
    }

    @Override
    public void onError(String key, String expression, Throwable throwable) {
        // Some error in expression..
    }
});

Environments

You can add environments objects or Realm models so you can use them later

RealmExpression.addEnvironmentObject("user", User.getCurrentUser(), isDisposable);

Example: engine.addExpression("A", "user.@getLastName()");

isDisposable allows you to discard the object when necessary.

Native classes

A native class is not a RealmObejct and can be accessed from whatever expression. RealmExpression has default native classes

DateNative accessed from @@date.

Methods

Access	Return	Params	Description	Example
.@now()	String date	Not support	Get the current date	@@date.@now()

DeviceNative accessed from @@device.

Methods

Access	Return	Params	Description	Example
.@randomUUID()	String UUID	Not support	Get random UUID	@@device.@randomUUID()
.@imei()	String IMEI	Not support	Get random UUID (Permission required since Android 6.0 Marshmallow)	@@device.@imei()
.@androidVersion()	String Android version	Not support	Get Android Version from Build.VERSION.RELEASE	@@device.@androidVersion()
.@appVersion()	String app version	Not support	Get app version name	@@device.@appVersion()
.@lastLocation()	String location	Not support	Get last know location with format 19.0460714,-98.2267667	@@device.@lastLocation()

Create native class

You can create a native class extends by NativeClass and access it by you custom key. To add this class it is necessary call to RealmExpression.addNewNativeClass(KEY, NativeClass);

Others instance methods

Code	Description
RealmExpression.dispose();	Discard all no disposable environment objects
RealmExpression.disposeAll()	Remove all environment objects
RealmExpression.removeEnvironment(KEY);	Removes an specific environment
RealmExpression.removeNativeClass(KEY);	Removes an specific NativeClass

Please start now! 😬

Write an expression

Sintax	Example	Description
@@	@@device.@androidVersion()	For reserved words
$_realmClass	$_client.@byId(...)	For Realm method class
$envObjectName	$client.@getName()	For Realm Objects
2*5/10	2*5/10	For simple math operation
@REUSE(objectName.@getName())	@REUSE(B1.@getName())	Where B1 is instance of 'client'

Examples

    
    RealmExpression.addEnvironmentObject("user", KUser.getCurrentUser(), false);
    
    RealmExpression engine = new RealmExpression.Builder()
          .addExpression("B1", "$user.@getFirstName()")
          .withTemplate("NAME: B1");
          
    engine.evaluateAsync(new OnEvaluationListener() {
            @Override
            public void onEvaluationResult(String template, Object result) {
                System.out.println("Template: " + template);
                System.out.println("Result: " + result);
                System.out.println("* * * * * * * * * * *");
            }

            @Override
            public void onExpressionResult(String key, String expression, Object result) {
                System.out.println("Key: " + key);
                System.out.println("Expression: " + expression);
                System.out.println("Result: " + result);
                System.out.println("= = = = = = = = = = = =");
            }

            @Override
            public void onError(String key, String expression, Throwable throwable) {

            }
        });

Output

NAME: Jhon

Love build this

License

Copyright 2018 javierpe

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.