Apex Reflection

Provides basic reflection for the Apex programming language.

Installation

npm i @cparra/apex-reflection

Usage

This library exposes a single function that handles parsing the body of an Apex top level type (class, interface, or enum) and returns the result.

import {reflect} from '@cparra/apex-reflection';

const classBody = 'public with sharing class ExampleClass {}';
const response = reflect(classBody);

If you wish to parse an Apex type that comes from a file, you can read the file contents and use that as the source to reflect

import * as fs from 'fs';
import {reflect} from '@cparra/apex-reflection';

const path = './MyClass.cls';
const rawFile = fs.readFileSync(path);
const response = reflect(rawFile.toString());

The reflect function returns a ReflectionResult which contains either the results of the parsed Type (which will either be a ClassMirror, an InterfaceMirror or an EnumMirror) or a ParsingError if the passed in body was not parsed successfully, with a message indicating where the error occurred.

Contributing

Even though this library is exposed as a Node.js library, the project's source code is written in Dart. The source can be found in the lib/src directory.

The Dart source code is transpiled to JS by dart2js through the default grinder workflow within tool/grind.dart.

To generate the JS files first set up grinder locally by following that package's instructions through its pub.dev listing, and then you can simply run grind. That build takes care of combining the output with preamble/preamble.js to achieve compatibility with Node.js. The resulting file is js/apex-reflection-node/out.js.

Tests

Both the Dart source code and the JS output must be tested.

The Dart tests live in the test directory. The Dart source code must have unit tests testing each individual Dart file as well as end-to-end tests that verify the overall parsing functionality.

The JS tests live in js/apex-reflection-node/__tests__. These are end-to-end tests that ensure that the transpiled JS code is working as intended.

JSON serialization

The reflection operation outputs a JSON representation of the Apex type, which is then deserialized on the JS side to return typed objects.

Serialization is handled through the json_serializable package, which helps automatically create the round-trip code for serialization and de-serialization.

When changing any of the model classes with serialization support, to re-build the serialization code run

pub run build_runner build

Parsing

The parsing algorithm relies on using ANTLR4 and its Dart target. Currently dart2js is not able to transpile the source from the antrl4 library hosted in pub.dev, so we rely on a local copy that fixes the transpilation issues, which lives in lib/antrl4-4.9.2.

To generate the Antlr4 Apex output run:

antlr4 -Dlanguage=Dart lib/src/antlr/grammars/apex/ApexLexer.g4 lib/src/antlr/grammars/apex/ApexParser.g4 -o lib/src/antlr/lib/apex/

To generate the Antlr4 Apexdoc output run:

antlr4 -Dlanguage=Dart lib/src/antlr/grammars/apexdoc/ApexdocLexer.g4 lib/src/antlr/grammars/apexdoc/ApexdocParser.g4 -o lib/src/antlr/lib/apexdoc/

Typescript

This library provides its own TS type definition.