graphql-tlc

$3

#### Install

* NPM - npm install graphql-tlc

#### Motivation

GraphQL normally requires a GraphQLSchema object passed along with each query
you give it to validate, interpret & execute. Typically this schema is constructed
by hand-crafting some verbose & noisy JavaScript.

See: starWarsSchema.js.

The equivalent schema in GraphQL Type Language is much more concise:
``
enum Episode { NEWHOPE, EMPIRE, JEDI }

type Human {
id: ID!
name: String
friends: [Character]
appearsIn: [Episode]
homePlanet: String
}

type Droid {
id: ID!
name: String
friends: [Character]
appearsIn: [Episode]
primaryFunction: String
}

union Character = Human | Droid
`

Given a specification of a data model in GraphQL Type Language, graphql-tlc automatically
generates the GraphQLSchema instance that GraphQL requires and binds its resolve methods
to a specified set of functions for querying (i.e., selecting) and mutating (i.e., insert,
update and delete mutations).

#### Example

`javascript
$ node --harmony-destructuring
> var tlc = require('graphql-tlc');
> var gql = require('graphql');
> var albums = [
... {'id': 1, 'name': 'Dark Side Of The Moon', 'releaseDate': 'March 1, 1973',
... 'artist': 'Pink Floyd'},
... {'id': 2, 'name': 'The Beatles', 'releaseDate': 'November 22, 1968',
... 'artist': 'The Beatles'},
... {'id': 3, 'name': 'The Wall', 'releaseDate': 'Auguest 1, 1982',
... 'artist': 'Pink Floyd'}];
> var dataResolver = {"query": function (typename, predicate) {
... console.assert(typename == "Album");
... if (predicate == "all()") return albums;
... else {
... var predicates = predicate.split("&");
... var filters = predicates.map(function(p) {
... var [field, value] = p.split("=");
... return function(elem) { return elem[field] == value; };
... });
... return albums.filter(function(elem) { return filters.every(function(f) { return f(elem); }); });
... }
... }, "create": function (typename, inputs) {
... inputs.id = albums.length + 1;
... albums.push(inputs);
... return inputs;
... }};
> var schema = tlc.getSchema(dataResolver,
... "type Album { id: ID! name: String releaseDate: String artist: String }");
> var printer = function(res) { console.log(JSON.stringify(res, null, 2)); };
> gql.graphql(schema, "{ Album(artist: \"Pink Floyd\") { name artist releaseDate } }").then(printer);

{
"data": {
"Album": [
{
"name": "Dark Side Of The Moon",
"artist": "Pink Floyd",
"releaseDate": "March 1, 1973"
},
{
"name": "The Wall",
"artist": "Pink Floyd",
"releaseDate": "August 1, 1982"
}
]
}
}

> gql.graphql(schema, "{ Album(artist: \"Pink Floyd\", name: \"The Wall\") { name artist releaseDate } }").then(printer);

{
"data": {
"Album": [
{
"name": "The Wall",
"artist": "Pink Floyd",
"releaseDate": "August 1, 1982"
}
]
}
}

> gql.graphql(schema, "{ Album(id: 2) { name artist releaseDate } }").then(printer);

{
"data": {
"Album": [
{
"name": "The Beatles",
"artist": "The Beatles",
"releaseDate": "November 22, 1968"
}
]
}
}

> gql.graphql(schema, "{ Albums { name artist releaseDate } }").then(printer);

{
"data": {
"Albums": [
{
"name": "Dark Side Of The Moon",
"artist": "Pink Floyd",
"releaseDate": "March 1, 1973"
},
{
"name": "The Beatles",
"artist": "The Beatles",
"releaseDate": "November 22, 1968"
},
{
"name": "The Wall",
"artist": "Pink Floyd",
"releaseDate": "Auguest 1, 1982"
}
]
}
}

> gql.graphql(schema, "mutation m { createAlbum(name:\"The Division Bell\", releaseDate: \"March 28, 1994\", artist:\"Pink Floyd\") { id name } }").then(printer);

{
"data": {
"createAlbum": {
"id": "4",
"name": "The Division Bell"
}
}
}

``

Copyright (c) 2015 Jonathan L. Leonard