Worked on the schema code

This commit is contained in:
2020-09-05 00:05:56 +10:00
parent e9655f1055
commit 7fa4c56bcc
6 changed files with 43 additions and 31 deletions

View File

@@ -1,6 +1,6 @@
{
"name": "simpleql",
"version": "1.0.0",
"version": "0.1.0",
"description": "",
"main": "server/server.js",
"directories": {

View File

@@ -21,7 +21,7 @@ let authors = [
},
];
//insert the authors into the books
//insert the authors into the books (relationship)
authors = authors.map(a => {
a.books = a.books.map(b => {
b.author = a;

View File

@@ -11,7 +11,7 @@ const database = require('./database.js');
//the handler routines
const handler = {
Book: (parent, scalars) => {
//takes an object which is the result of the parent query, if there is one { typeName: 'Author', scalars: [scalars], context: parentObject }
//takes an object which is the result of the parent query, if there is one { typeName: 'Author', scalars: [scalars] }
//takes an array of scalar types as objects: { typeName: 'String', name: 'title' }
//must return an array of objects containing the results

View File

@@ -2,13 +2,13 @@ module.exports = `
scalar Date
type Book {
String title
!String title
Author author
Date published
}
type Author {
!String name
!Book[] books
Book[] books
}
`;

View File

@@ -2,6 +2,7 @@
const express = require('express');
const bodyParser = require('body-parser');
const app = express();
app.use(bodyParser.text());
//test the library

View File

@@ -1,13 +1,24 @@
//reserved keywords that can't be used as identifiers
const keywords = ['type', 'scalar'];
//the main function to be returned
const main = (schema, handler) => {
const typeGraph = buildTypeGraph(schema);
let typeGraph;
try {
typeGraph = buildTypeGraph(schema);
}
catch(e) {
console.log('caught in typegraph', e);
return null;
}
console.log(typeGraph);
//the receiving function - this will be called multiple times
return async reqBody => {
//parse the query
const tokens = reqBody.split(/(\s+)/).filter(s => s.trim().length > 0);
const tokens = reqBody.split(/(\s+)/).filter(s => s.trim().length > 0); //TODO: proper token parsing
let pos = 0;
try {
@@ -17,12 +28,12 @@ const main = (schema, handler) => {
case 'update':
case 'delete':
throw 'keyword not implemented: ' + tokens[pos];
//TODO
//TODO: implement these keywords
break;
//no leading keyword - regular query
default:
const result = await parseQuery(handler, tokens, pos, typeGraph[tokens[pos]], typeGraph);
const result = await parseQuery(handler, tokens, pos, typeGraph);
return [200, result];
@@ -47,7 +58,7 @@ const buildTypeGraph = schema => {
};
//parse the schema
const tokens = schema.split(/(\s+)/).filter(s => s.trim().length > 0);
const tokens = schema.split(/(\s+)/).filter(s => s.trim().length > 0); //TODO: proper token parsing
let pos = 0;
while (tokens[pos]) {
@@ -57,12 +68,12 @@ const buildTypeGraph = schema => {
graph[tokens[pos]] = parseCompoundType(tokens, pos);
//advance to the end of the compound type
while(tokens[pos] && tokens[pos++] != '}');
pos = eatBlock(tokens, pos + 2); //+2: skip the name & opening bracket
break;
case 'scalar':
if (['type', 'scalar'].includes(graph[tokens[pos]])) {
if (keywords.includes(graph[tokens[pos]])) {
throw 'Unexpected keyword ' + graph[tokens[pos]];
}
@@ -95,11 +106,11 @@ const parseCompoundType = (tokens, pos) => {
//parse the extra typing data
let array = false;
let nullable = true;
let required = false;
//not nullable
if (type[0] === '!') {
nullable = false;
required = true;
type = type.slice(1);
}
@@ -114,32 +125,32 @@ const parseCompoundType = (tokens, pos) => {
checkAlphaNumeric(name);
//can't use keywords
if (['type', 'scalar'].includes(type) || ['type', 'scalar'].includes(name)) {
throw 'Unexpected keyword found as type field or type name';
if (keywords.includes(type) || keywords.includes(name)) {
throw 'Unexpected keyword found as type field or type name (' + type + ' ' + name + ')';
}
//check for duplicate fields
if (Object.keys(compound).includes(name)) {
throw 'Unexpected duplicate filed name';
throw 'Unexpected duplicate field name';
}
//finally, push to the compound definition
compound[name] = {
typeName: type,
array: array,
nullable: nullable,
required: required,
};
}
return compound;
};
const parseQuery = async (handler, tokens, pos, typeGraph, superTypeGraph, parent = null) => {
const parseQuery = async (handler, tokens, pos, typeGraph, parent = null) => {
//returns an object result from handler
//get the "parent object" contents for sub-objects
const queryName = superTypeGraph[tokens[pos]] ? null : tokens[pos]; //if you're a type, name = null
const queryType = superTypeGraph[tokens[pos]] ? tokens[pos] : superTypeGraph[parent.typeName][tokens[pos]].typeName; //use this type or derive the type from the parent
// const queryName = typeGraph[tokens[pos]] ? null : tokens[pos]; //if you're a type, name = null
// const queryType = typeGraph[tokens[pos]] ? tokens[pos] : typeGraph[parent.typeName][tokens[pos]].typeName; //use this type or derive the type from the parent
//move on
pos++;
@@ -165,7 +176,7 @@ const parseQuery = async (handler, tokens, pos, typeGraph, superTypeGraph, paren
}
//type is a scalar, and can be queried
if (superTypeGraph[typeGraph[tokens[pos]].typeName].scalar) {
if (typeGraph[typeGraph[tokens[pos]].typeName].scalar) {
//push the scalar object to the queryFields
scalarFields.push({ typeName: typeGraph[tokens[pos]].typeName, name: tokens[pos] });
@@ -178,9 +189,8 @@ const parseQuery = async (handler, tokens, pos, typeGraph, superTypeGraph, paren
handler,
tokens,
pos2,
superTypeGraph[typeGraph[tokens[pos2]].typeName],
superTypeGraph,
{ typeName: queryType, scalars: scalarFields, context: result }
typeGraph,
{ typeName: queryType, scalars: scalarFields } //parent object
)]);
pos = eatBlock(tokens, pos);
@@ -192,6 +202,7 @@ const parseQuery = async (handler, tokens, pos, typeGraph, superTypeGraph, paren
let results = handler[queryType](parent, scalarFields);
//WTF
results = await Promise.all(results.map(async res => {
const tuples = await Promise.all(deferredCalls.map(async call => await call(res)));
@@ -219,7 +230,7 @@ const eatBlock = (tokens, pos) => {
}
}
return pos;
return ++pos;
};
//return