I have
Page.findById(pageId).then(page => {
const pageId = page.id;
..
});
My problem is that if no page id is given, it should just take the first available page given some conditions, which is done by
Page.findOne({}).then(page => {
const pageId = page.id;
..
});
but if no page is found, it should create a new page and use this, which is done with
Page.create({}).then(page => {
const pageId = page.id;
..
});
But how do I combine all this to as few lines as possible?
I have a lot of logic going on inside
page => { ... }
so I would very much like to do this smart, so I can avoid doing it like this
if (pageId) {
Page.findById(pageId).then(page => {
const pageId = page.id;
..
});
} else {
Page.findOne({}).then(page => {
if (page) {
const pageId = page.id;
..
} else {
Page.create({}).then(page => {
const pageId = page.id;
..
});
}
});
}
I am thinking I maybe could assign a static to the schema with something like
pageSchema.statics.findOneOrCreate = function (condition, doc, callback) {
const self = this;
self.findOne(condition).then(callback).catch((err, result) => {
self.create(doc).then(callback);
});
};
As per the Mongoose docs:
As per previous SO answer
Model.findByIdAndUpdate()
"Finds a matching document, updates it according to the update arg, passing any options, and returns the found document (if any) to the callback."
In the options set upsert to true:
upsert: bool - creates the object if it doesn't exist. defaults to false.
Model.findByIdAndUpdate(id, { $set: { name: 'SOME_VALUE' }}, { upsert: true }, callback)
Related to Yosvel Quintero's answer which didn't work for me:
pageSchema.statics.findOneOrCreate = function findOneOrCreate(condition, callback) {
const self = this
self.findOne(condition, (err, result) => {
return result ? callback(err, result) : self.create(condition, (err, result) => { return callback(err, result) })
})
}
And then use it like:
Page.findOneOrCreate({ key: 'value' }, (err, page) => {
// ... code
console.log(page)
})
Promise async/await version.
Page.static('findOneOrCreate', async function findOneOrCreate(condition, doc) {
const one = await this.findOne(condition);
return one || this.create(doc);
});
Usage
Page.findOneOrCreate({ id: page.id }, page).then(...).catch(...)
Or
async () => {
const yourPage = await Page.findOneOrCreate({ id: page.id }, page);
}
Each Schema can define instance and static methods for its model. Statics are pretty much the same as methods but allow for defining functions that exist directly on your Model
Static method findOneOrCreate:
pageSchema.statics.findOneOrCreate = function findOneOrCreate(condition, doc, callback) {
const self = this;
self.findOne(condition, (err, result) => {
return result
? callback(err, result)
: self.create(doc, (err, result) => {
return callback(err, result);
});
});
};
Now when you have an instance of Page you can call findOneOrCreate:
Page.findOneOrCreate({id: 'somePageId'}, (err, page) => {
console.log(page);
});
One lines solution with async/await:
const page = Page.findOne({}).then(p => p || p.create({})
If you don't want to add a static method to the model, you can try to move some things around and at least not to have all these callback nested levels:
function getPageById (callback) {
Page.findById(pageId).then(page => {
return callback(null, page);
});
}
function getFirstPage(callback) {
Page.findOne({}).then(page => {
if (page) {
return callback(null, page);
}
return callback();
});
}
let retrievePage = getFirstPage;
if (pageId) {
retrievePage = getPageById;
}
retrievePage(function (err, page) {
if (err) {
// #todo: handle the error
}
if (page && page.id) {
pageId = page.id;
} else {
Page.create({}).then(page => {
pageId = page.id;
});
}
});
The solutions posted here ignore that this pattern is most common when there's a unique index on a field or a combination of fields. This solution considers unique index violation errors correctly:
mongoose.plugin((schema) => {
schema.statics.findOrCreate = async function findOrCreate(key, attrs) {
try {
return await this.create({ ...attrs, ...key });
} catch (error) {
const isDuplicateOnThisKey =
error.code === 11000 &&
Object.keys(error.keyPattern).sort().join(',') ===
Object.keys(key).sort().join(',');
if (isDuplicateOnThisKey) {
const doc = await this.findOne(error.keyValue);
doc.set(attrs);
return await doc.save();
}
throw error;
}
};
});
Usage:
await Post.findOrCreate({ slug: 'foobar' }, { title: 'Foo Bar', body });
try this..
var myfunc = function (pageId) {
// check for pageId passed or not
var newId = (typeof pageId == 'undefined') ? {} : {_id:pageId};
Page.findOne(pageId).then(page => {
if (page)
const pageId = page.id;
else { // if record not found, create new
Page.create({}).then(page => {
const pageId = page.id;
});
}
});
}
Related
I'm curious how to create a simple version of express's middleware by creating an array of functions and using .reduce to loop over them.
function fullPath(context) {
context.fullPath = nodePath.isAbsolute(context.path) ? context.path : nodePath.join(context.cwd, context.path);
}
function extension(context) {
context.extension = nodePath.extname(context.path);
}
function contents(context, callback) {
return fs.readFile(context.fullPath, { encoding: 'utf8' }, (err, contents) => {
if (err) throw err;
context.contents = contents;
return callback(null, context);
});
}
function fileLoader(context, callback) {
return [
fullPath,
extension,
contents
].reduce((context, fn) => {
return fn(context, callback)
}, context)
}
What should the logic within .reduce be to cycle each function, pass a callback to each, and have them nest properly, then call the parent callback at the end?
Here's this working:
const nodePath = require('path');
const fs = require('fs');
function fullPath(context) {
console.log('fullPath')
context.fullPath = nodePath.isAbsolute(context.path) ? context.path : nodePath.join(context.cwd, context.path);
}
function extension(context) {
console.log('extension')
context.extension = nodePath.extname(context.path);
}
function contents(context, callback) {
console.log('contents')
return fs.readFile(context.fullPath, { encoding: 'utf8' }, (err, contents) => {
console.log('contents-i')
if (err) return callback(err);
context.contents = contents;
return callback();
});
}
function middleware(stack) {
return (context = {}, master) => {
var hasError = false
return stack.reduceRight((callback, fn) => {
if (hasError) return () => {};
return () => {
const isAsync = fn.length === 2
if (isAsync) {
fn(context, (err) => {
if (err) {
hasError = true
return master(err);
}
callback(null, context);
})
} else {
fn(context)
callback(null, context)
}
}
}, master)()
}
}
const fileLoader = middleware([fullPath, extension, contents])
fileLoader({ path: './example.md', cwd: '' }, (err, context) => {
console.log({ err, context })
})
Been trying everything to get this to work specifically the async each method. for (const element of resultsHistory) didn't work either.
I'm trying to modify the result array from a previous query by running a foreach over it and doing a mysql query.
However this needs to wait for the query to complete.
Is there a way to access these results without the setTimeout(function() { } I put manually in order to wait for the query to finish?
function getUserLikes(params, callback) {
var usersArrayCat = [];
console.log(`length of array ${params.length}`)
// 1 here means 1 request at a time
async.eachLimit(params, 1, function (element, cb) {
element.liked = 0;
var queryLiked = `SELECT * from users_likes WHERE user_id = \"${req.body.userid}\" AND product_id = \"${element.product_id}\"`;
connectionPromise.query(queryLiked, function (err, result) {
if (!result) {
} else if (result.length == 0) {
} else {
element.liked = result[0].userlike;
usersArrayCat.push(element);
// console.log(usersArrayCat);
cb();
}
})
}, function (err) {
if (err) return callback(err);
callback(null, usersArrayCat)
});
};
getUserLikes(resultsHistory, function (e) {
console.log(e);
});
if(!res.headersSent) {
setTimeout(function() {
res.send(JSON.stringify({"status": 200 ,"error": null, "top3":resultsHistory}));
}, 150);
}
Managed to get it working like this, but still not sure if this is the right way.
async function getUserLikes(resultsHistory) {
for (const element of resultsHistory) {
element.liked = 0;
let queryLiked = `SELECT * from users_likes WHERE user_id = \"${req.body.userid}\" AND product_id = \"${element.product_id}\"`;
let liked = await conn2.query(queryLiked);
if (liked[0]) {
element.liked = liked[0].userlike;
}
}
if(!res.headersSent) {
conn2.release();
let newres = resultsHistory.sort(
firstBy(function (v1, v2) { return v2.rating - v1.rating; })
.thenBy(function (v1, v2) { return v2.dranktimes - v1.dranktimes; })
).filter( function(history) {
return history.event === eventName;
}).slice(0, 3);
res.send({"status": 200 ,"error": null, "top3":newres});
}
}
getUserLikes(resultsHistory);
See my answer:
function getUserLikes(params, callback) {
var usersArrayCat = [];
console.log(`length of array ${params.length}`)
// 1 here means 1 request at a time
async.eachLimit(params, 1, function (element, cb) {
element.liked = 0;
var queryLiked = `SELECT * from users_likes WHERE user_id = \"${req.body.userid}\" AND product_id = \"${element.product_id}\"`;
connectionPromise.query(queryLiked, function (err, result) {
if (!result) {
} else if (result.length == 0) {
} else {
element.liked = result[0].userlike;
usersArrayCat.push(element);
// console.log(usersArrayCat);
}
cb();
})
}, function (err) {
if (err) return callback(err);
callback(null, usersArrayCat)
});
};
getUserLikes(resultsHistory, function (e, usersArrayCat) {
if (e) {
console.log(e);
return res.send({status: 400, error: e}); // your error response
}
console.log(usersArrayCat); // your usersArrayCat with liked property
res.send(JSON.stringify({ // why your need return a string intead of json object ???
"status": 200,
"error": null,
"top3": usersArrayCat // I think return `usersArrayCat` is a right way
}));
});
I have two js files. i am able to get data from mongodb by calliing bookDao.getActiveBookByCategoryId().
My Problem
In categoryDao.js file i am trying to update resultJson.book_countinside BookDao.getActiveBookByCategoryId() method. but it is not updating. So may i know how to fix this.
here book_count property in resultJson is still 0.
categoryDao.js
module.exports.getAllActiveCategory = (callback) => {
Category.find({
is_delete : false
}, (error, result) => {
if(error) {
console.log(error);
callback(commonUtil.ERROR);
}
if(result) {
var categoryArray = [];
for(var i=0; i<result.length; i++) {
var categorySingle = result[i];
var resultJson = {
_id : categorySingle._id,
category_name : categorySingle.category_name,
created_on : categorySingle.created_on,
book_count : 0
}
BookDao.getActiveBookByCategoryId(categorySingle._id, (bookResult) => {
if(bookResult) {
if(bookResult.length > 0) {
resultJson.book_count = bookResult.length;
}
}
});
categoryArray.push(resultJson);
}
callback(categoryArray);
}
});
}
bookDao.js
module.exports.getActiveBookByCategoryId = (categoryId, callback) => {
Book.find({
is_delete : false,
category : categoryId
}, (error, result) => {
if(error) {
console.log(error);
callback(commonUtil.ERROR);
}
if(result) {
callback(result);
}
});
}
Try this, In your code categoryArray.push(resultJson); will not wait for BookDao.getActiveBookByCategoryId to finish because of async behavior.
module.exports.getActiveBookByCategoryId = (categoryId) => {
return Book.count({
is_delete: false,
category: categoryId
});
}
module.exports.getAllActiveCategory = async () => {
try {
// Find all category
const result = await Category.find({
is_delete: false
});
// Create array of promise
const promises = result.map(categorySingle => BookDao.getActiveBookByCategoryId(categorySingle._id));
// Get array of Category count
const data = await Promise.all(promises);
// update count in result
return result.map((categorySingle, i) => {
categorySingle.book_count = data[i];
return categorySingle;
});
} catch (error) {
console.log(error);
}
}
I have an Airtable base that I can retrieve records from (see code below), but I'd like to get the value for other fields besides just "Location". Using "console.log('Retrieved: ', record.get('Location'));", how do I modify this line to include in the output the field values for a field called "Size" in addition to the "Location" field? I tried "console.log('Retrieved: ', record.get('Location', 'Size'));", but that didn't work.
Here's an excerpt from my code:
// Lists 3 records in Bins
base('Bins').select({
// Selecting the first 3 records in Grid view:
maxRecords: 3,
view: "Grid view"
}).eachPage(function page(records, fetchNextPage) {
// This function (`page`) will get called for each page of records.
records.forEach(function(record) {
console.log('Retrieved: ', record.get('Location'));
});
// To fetch the next page of records, call `fetchNextPage`.
// If there are more records, `page` will get called again.
// If there are no more records, `done` will get called.
fetchNextPage();
}, function done(err) {
if (err) { console.error(err); return; }
});
OUTPUT
Retrieved 170000118
Retrieved 170000119
Retrieved 170000120
I found this repo to help in when I tried to product situations like this.
A wrapper for common functions for accessing data on an airtable.com database. All queries return promises.
Here is how it works if you want to avoid using an npm package. But ultimatly the jist of it is to either use request or some short of promise fulfillment menthod to retrive the Records.
import Airtable from 'airtable'
import _ from 'lodash'
const ENDPOINT_URL = 'https://api.airtable.com'
let API_KEY // Can only set the API key once per program
export default class AirTable {
constructor({apiKey, databaseRef}) {
if(!API_KEY) {
API_KEY = apiKey
Airtable.configure({
endpointUrl: ENDPOINT_URL,
apiKey: API_KEY
});
}
this.base = Airtable.base(databaseRef)
this.get = {
single: this.getSingleRecordFrom.bind(this),
all: this.getAllRecordsFrom.bind(this),
match: this.getAllMatchedRecordsFrom.bind(this),
select: this.getRecordsSelect.bind(this)
}
this.insert = this.createRecord.bind(this)
this.add = this.insert
this.create = this.insert
this.update = this.updateRecord.bind(this)
this.set = this.update
this.remove = this.deleteRecord.bind(this)
this.delete = this.remove
this.destroy = this.remove
this.rem = this.remove
}
async createRecord({tableName, data}) {
return new Promise((resolve, reject) => {
this.base(tableName).create(data, (err, record) => {
if (err) {
console.error(err)
reject()
return
}
console.log("Created " + record.getId())
resolve(record)
})
})
}
async updateRecord({tableName, id, data}) {
return new Promise((resolve, reject) => {
this.base(tableName).update(id, data, (err, record) => {
if (err) {
console.error(err)
reject()
return
}
console.log("Updated " + record.getId())
resolve(record)
})
})
}
async deleteRecord({tableName, id, data}) {
return new Promise((resolve, reject) => {
this.base(tableName).destroy(id, (err, record) => {
if (err) {
console.error(err)
reject()
return
}
console.log("Deleted " + record.getId())
resolve(record)
})
})
}
async getSingleRecordFrom({tableName, id}) {
console.log(tableName, id)
return new Promise((resolve, reject) => {
this.base(tableName).find(id, function(err, record) {
if (err) {
console.error(err)
reject(err)
}
resolve(record)
})
// console.log(record);
})
}
async getAllRecordsFrom(tableName) {
return this.getRecordsSelect({tableName, select: {} })
}
async getAllMatchedRecordsFrom({tableName, column, value}) {
return this.getRecordsSelect({tableName, select: {filterByFormula:`${column} = ${value}`} }) // TODO: validate input
}
async getRecordsSelect({tableName, select}) {
return new Promise((resolve, reject) => {
let out = []
this.base(tableName).select(select).eachPage((records, fetchNextPage) => {
// Flatten single entry arrays, need to remove this hacky shit.
_.map(records, r => {
_.forOwn(r.fields, (value, key) => { // If array is single
if(_.isArray(value) && value.length == 1 && key != 'rooms') {
r.fields[key] = value[0]
}
});
})
out = _.concat(out, records)
fetchNextPage();
}, (err) => {
if (err) {
console.error(err)
reject(err)
} else {
// console.log(JSON.stringify(out, null, 4))
// console.log("HI")
resolve(out)
}
})
})
}
}
Hope this Makes sense, Also trying to make an API-Proxy fetching a whole table or even use Express to fetch record id's as arrays can work as well
You can use this code line.
records.forEach(function(record) {
console.log('Retrieved: ', record.get('Location') + ' ' + record.get('Size'));
});
I am writing an service, where I retrieve a list of items from a another service, then iterate over result performing keystone.list operation(s).
I am loosing the return status in the find/exec operation. I have tried promises, async, etc.
If someone could point out the correct way to implement this, I would appreciate it.
general implementation:
exports = module.exports = function (req, res) {
var rtn = {
added: 0,
count: 0
}
service(params)
.then(function(svcResult) {
svcResult.forEach(function(item) {
rtn.count++; // <-- correctly seen in apiresponse
Artifact.model.find()
.where({ artifactId: item.id})
.exec(function(err, result) {
if (result.length == 0) {
result = new Artifact.model({
... populate from item ....
});
result.save();
rtn.added++; // <-- not seen in api response
});
});
res.apiResponse(rtn);
});
}
for starters, exec is an async call, which you are ignoring in your res.apiResponse and thus count is incremented and not added, to make life easy, I am moving the exec call outside and wrapping it with promise:
function pExec(id){
return new Promise(function(resolve, reject){
Artifact.model.find()
.where({ artifactId: id})
.exec(function(err, result){
console.log('result: ', result); // there is a possibility that this is not empty array, which seems to be the only case when you increment added value
err? reject(err): resolve(result);
});
});
}
exports = module.exports = function(req, res){ // I think it is 'exports' not 'exposts'
service(params)
.then(function(svcResult) {
var promises = svcResult.map(function(item){
rtn.count++;
return pExec(item.id).then(function(result){
if (result.length == 0) {
result = new Artifact.model({
//... populate from item ....
});
result.save(); // again this might be an async call whose response you might need before incrementing added...
rtn.added++; // <-- not seen in api response
};
});
});
Promise.all(promises).then(function(){
res.apiResponse(rtn);
});
});
}
Thanks... Here is what I have come up with so far....
function getArtifact(id) {
return new Promise(function (resolve, reject) {
Artifact.model.findOne()
.where({artifactId: id})
.exec(function (err, artifact) {
err ? resolve(null) : resolve(artifact);
});
});
}
function createArtifact(item) {
return new Promise(function (resolve, reject) {
var artifact = new Artifact.model({
// ... populate from item ....
});
artifact.save(function (err, artifact) {
err ? resolve(null) : resolve(artifact);
});
});
}
exports = module.exports = function (req, res) {
var rtn = {
success: false,
count: 0,
section: '',
globalLibrary: {
Added: 0,
Matched: 0
},
messages: [],
};
if (!req.user || !req.user._id) {
rtn.messages.push("Requires Authentication");
return res.apiResponse(rtn);
}
if (!req.params.section) {
rtn.messages.push("Invalid parameters");
return res.apiResponse(rtn);
}
var userId = req.user._id;
var section = req.params.section;
rtn.section = section;
service(section)
.then(function (svcResult) {
if (svcResult.length == 0 || svcResult.items.length == 0) {
rtn.messages.push("Retrieved empty collection");
return;
}
rtn.messages.push("Retrieved collection");
var artifacts = svcResult.items(function (item) {
rtn.count++;
return getArtifact(item.objectid)
.then(function (artifact) {
if (!artifact || artifact.length == 0) {
rtn.messages.push("Global Library Adding: " + item.name['$t']);
rtn.globalLibrary.Added++;
artifact = createArtifact(item);
} else {
rtn.globalLibrary.Matched++;
}
return artifact;
})
});
Promise.all(artifacts)
.then(function () {
rtn.success = true;
res.apiResponse(rtn);
});
});
}