Last active
January 5, 2016 17:17
-
-
Save vslinko/29d926bc069caaa32553 to your computer and use it in GitHub Desktop.
Neo4j Helpers
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| 'use strict'; | |
| const CypherQuery = require('./cypher').CypherQuery; | |
| module.exports = function createQueryExecutor(context) { | |
| const executor = function executeQuery(query) { | |
| if (typeof query === 'function') { | |
| return query(executor); | |
| } | |
| const rawQuery = query instanceof CypherQuery | |
| ? query.getRawQuery() | |
| : query; | |
| return new Promise((resolve, reject) => { | |
| context.cypher(rawQuery, (err, result) => { | |
| if (err) { | |
| reject(err); | |
| } else { | |
| resolve(result); | |
| } | |
| }); | |
| }); | |
| }; | |
| return executor; | |
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| 'use strict'; | |
| const createQueryExecutor = require('./createQueryExecutor'); | |
| module.exports = function createTransactionExecutor(db) { | |
| return function executeTransaction(cb) { | |
| const tx = db.beginTransaction(); | |
| const executeQuery = createQueryExecutor(tx); | |
| return Promise.resolve(executeQuery(cb)) | |
| .then((result) => { | |
| return new Promise((resolve, reject) => { | |
| tx.commit((err) => { | |
| if (err) { | |
| reject(err); | |
| } else { | |
| resolve(result); | |
| } | |
| }); | |
| }); | |
| }) | |
| .then(undefined, (err) => { | |
| if (tx.state === tx.STATE_OPEN || tx.state === tx.STATE_PENDING) { | |
| return new Promise((resolve, reject) => { | |
| tx.rollback(() => { | |
| reject(err); | |
| }); | |
| }); | |
| } | |
| throw err; | |
| }); | |
| }; | |
| }; |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| 'use strict'; | |
| class CypherQuery { | |
| constructor(strings, values) { | |
| this._strings = strings; | |
| this._values = values; | |
| } | |
| getRawQuery() { | |
| return this._getRawQuery({paramPrefix: 'p_'}); | |
| } | |
| _getRawQuery(config) { | |
| const paramPrefix = config.paramPrefix; | |
| return this._strings | |
| .reduce((rawQuery, string, index) => { | |
| const query = rawQuery.query; | |
| const params = rawQuery.params; | |
| if (index === 0) { | |
| return {query: string, params: {}}; | |
| } | |
| const paramIndex = index - 1; | |
| const value = this._values[paramIndex]; | |
| if (value instanceof CypherQuery) { | |
| const options = value._getRawQuery({ | |
| paramPrefix: paramPrefix + paramIndex + '_', | |
| }); | |
| return { | |
| query: `${query}${options.query}${string}`, | |
| params: Object.assign({}, params, options.params), | |
| }; | |
| } | |
| return { | |
| query: `${query}{${paramPrefix}${paramIndex}}${string}`, | |
| params: Object.assign({}, params, { | |
| [`${paramPrefix}${paramIndex}`]: value, | |
| }), | |
| }; | |
| }, {query: '', params: {}}); | |
| } | |
| } | |
| function cypher(strings) { | |
| const values = Array.prototype.slice.call(arguments, 1); | |
| return new CypherQuery(strings, values); | |
| } | |
| module.exports.CypherQuery = CypherQuery; | |
| module.exports.cypher = cypher; |
@Pepeye I'm on a similar learning path myself, haven't tried this code yet, but looking forward to it. Would be great to collaborate on learning resources! Have you seen this one yet: https://github.com/chentsulin/awesome-graphql ? It seems there's not too many GraphQL + Neo4j resources out there yet...
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
@vslinko Hi - I was looking through your Ripster repo and must say well done. I use neo4j a lot and recently discovered React/Redux, Graphql and Relay.
I'm particularly interested right now in moving an existing Neo4j + Rails api to Neo4j + Node + Graphql. Could you I ask you a for a big favour - to comment the above 3 gist which i see is also featured in the ripster: src/graphql/db.js file.
I can follow most of the code but a little lost here - the bit I'm not following so well is in the
_getRawQuerymethod in thecypher.jsabove.