Your browser does not seem to support JavaScript. As a result, your viewing experience will be diminished, and you may not be able to execute some actions.

Please download a browser that supports JavaScript, or enable it if it's disabled (i.e. NoScript).

LevelDB in NodeJS

K
kalena last edited by

PHP wasted using MySQL. Trying to write a website on Express.
I need to implement the copying/registration system using LevelDb. I was wondering if there's no class at all.
Specify how this system can be implemented: it is acceptable that data be stored as
key: Nick Igroka; values: password, mail, etc.
Thank you.
Reply Quote 0
1 Reply Last reply
jeanid last edited by

I can tell one level-DB violinist on youtube. https://www.youtube.com/watch?v=rcILF2wfzYk ♪ It's quite detailed, and I looked for interest. But it's more interesting until it's over.
Reply Quote 0
1 Reply Last reply

2
Posts

0
Views

Suggested Topics

J

JS: Why return returns undefined?
Software Programming • javascript • • jules

2

0
Votes

2
Posts

0
Views

T

To ensure that the function always returns the required value (number, line or the same) undefined(a) The necessary value shall be returned when each branch passes, or the value shall be returned somewhere outside the conditions.Besides, I'm looking at your code and I see what for. position < 0 Nothing comes back. If you were considering all the branches of the conditions, it would not be too bad to deal clearly with such conditions as to be seen - the condition was not forgotten (or to mention it in the commentary).In your case, provided if (list.rest) {...} Nothing comes back. It's tantamount. return undefined; at the end of the function.Accordingly, in order to correct your mistake, it is necessary to correct your code, for example:function nth(list, position){ if (position == 0) { console.log(list.value); return list.value; } else if (position > 0) { position--; if (list.rest) { list = list.rest; return nth(list, position); } else { return undefined; } } return undefined; } But a lot of conditions (the more invested) make it difficult to read the program. return) So it would be nice to rewrite your function. I'd do it, for example:function nth(list, position){ if (position == 0) { console.log(list.value); return list.value; } if (position < 0 || !list.rest) { return undefined; } position--; list = list.rest; return nth(list, position); } There are a number of different views, but this is a separate story.
Y

Duda NodeJS, import modules
Software Programming • nodejs • • yajahira

2

0
Votes

2
Posts

0
Views

The code you've published looks a lot in applications built with Express. You're just going through. instance already configured to a module where the routes that Express will handle are mapped.I just didn't understand why you can use app as a parameter when it hasn't even been importedWell, You don't need to import something directly to use.. Yes from module B export a function, then when you import that module you import the function and like any function you can pass parameters. There is neither magic nor anything in this, nor is it a special characteristic of CommonJS (Freedom for modularization of JavaScript code adapted and implemented in Node.js), JavaScript simply works like this. In Java for example, it is the same; in class A you import one class, create an object and you can pass this as a parameter in the other class method.On the other hand, that approach is not very flexible. It is best to map all routes using the router that Express provides:const router = require('express').Router(); const Controller = require('../controllers/index'); router .get('/', Controller.index) .get('/:id', Controller.findById) .post('/', Controller.create) .patch('/:id', Controller.update) .delete('/:id', Controller.remove); So you effectively separate your application into layers. Preferably, do not add handlers directly on the routes because it is not direct responsibility of the router; the responsibility is of the handlers and it is good practice to have them in a separate layer so that minimic dependencies between them.
T

Is there a Web equivalent.Config in Angular 4/5?
Software Programming • javascript angular typescript web.c languageonfig • • terrea

2

0
Votes

2
Posts

0
Views

In the folder app/environment/ You will find 2 files called:environment.prod.ts environment.ts Where environment.prod.ts will be the production configuration and in environment.ts development.You'd have something like:export const environment = { production: false, url: '192.169.1.114:8080' }; And in environment.prod.ts:export const environment = { production: true, url: 'https:/urlproduccion.com/api/' }; Then in your code you import the object environment:import { environment } from '../../environments/environment'; this.http.get(environment.url) ... And angular CLI will know what to load according to the type build of the app if it is --prod or development.
G

Socket Disconnect Nodejs
Software Programming • javascript node.js soc languageket • • gionna

2

0
Votes

2
Posts

0
Views

B

Have you tried using the socket.io library along with the express? The process is easy to understand and use. https://socket.io/ The socket example server: socket. js, then node socket. js is in the air.const port = process.env.PORT || 3001; //porta padrão var app = require('express')(); var http = require('http').createServer(app); const socketio = require('socket.io'); var io = socketio(http, {perMessageDeflate: false}); http.listen(port, () => { console.info(`Servidor socket inicializado usando express na porta ${port}`); }); io.set('transports', ['websocket']); io.on("connection", (socket) => { console.info(Client entrou [id=${socket.id}]); socket.on("disconnect", () => { console.info(`Client saiu [id=${socket.id}]`); }); socket.on("mensagem-enviada", dados => { socket.broadcast.emit('mensagem-repassada', dados); console.log(`mensagem recebida e repassada: ${JSON.stringify(dados)}`) }); }); On the client side, you can use this: <script type="text/javascript"> var socket = io('http://localhost:3001', {transports: ['websocket']}); socket.on('connect', () => { console.log("socket conseguiu conectar ao servidor"); }); socket.on('mensagem-repassada', data => { console.log("mensagem recebida que foi repassada:"); console.log(data); }); // para enviar ao socket para basta chamar a funçao enviarMensagem passando os dados que vai enviar o servidor function enviarMensagem(dados){ socket.emit("mensagem-enviada", dados); } </script>
E

Repeat of element
Software Programming • javascript vue.js • • emran

2

0
Votes

2
Posts

0
Views

Use the index for duplication, key is also mandatory in vue2. 2.0+<ul> <li v-for="index in 10" :key="index"> {{ n }} </li> </ul> Details. https://ru.vuejs.org/v2/guide/list.html#v-for-%D0%B8-%D0%B4%D0%B8%D0%B0%D0%BF%D0%B0%D0%B7%D0%BE%D0%BD%D1%8B
E

How to make an if according to 3 times clicked a button?
Software Programming • javascript • • esther

2

0
Votes

2
Posts

0
Views

R

To perform an action every 3 times you press a button you have only to create a counter and update it in the click event.Look at this example:(function(){ var contador = 0; document.getElementById('play').addEventListener('click', function(){ if (contador === 2){ alert('Tercera vez que se pulsa el botón'); contador = 0; } else{ contador++; } }); })();<input id="play" type="button" value="Jugar">
To which this error is due in NodeJS
Software Programming • nodejs • • Marcee

2

0
Votes

2
Posts

0
Views

C

The problem is that somewhere in your code you're trying to change response or res once the res.send() It's already sent.
R

How do you use two kernels in nodejs?
Software Programming • node.js • • Rossere

2

0
Votes

2
Posts

0
Views

A

I can offer an option using the sluster module. Tested the decision for NodeJS 4.1.2 version.var cluster = require('cluster'); var http = require('http'); var numCPUs = require('os').cpus().length; if (cluster.isMaster) { // Fork workers. var workers = []; for (var i = 0; i < numCPUs && i < 2; i++) { workers.push(cluster.fork()); } //set worker technical callbacks cluster.on('exit', function(worker, code, signal) { console.log('worker ' + worker.process.pid + ' died'); }); cluster.on('online', function(worker, code, signal) { console.log('worker ' + worker.id + ' ready'); }); //send messages to workers workers[0].send(0); workers[1].send(1); //set callback for worker responses cluster.on('message', function(msg) { console.log("Master process received message "+msg); workers[msg].kill(); }); } else { //worker logic for messages from master process process.on('message', function(msg) { if (msg == 0) {console.log("One logic");} else if (msg == 1) {console.log("Second logic");} console.log("Worker with id=" + cluster.worker.id + " received " + msg); process.send(msg); }); }
T

Organize board within modal
Software Programming • javascript php html css datatables • • tahishae

2

0
Votes

2
Posts

0
Views

N

only work on ie9+, Chrome 34+, Firefox 19+, Safari 7+, Android 4.4+ and iOS 6+style="max-height: calc(100vh - 210px);overflow-y: auto"; I don't know if you're using boostrap I recommend you add https://librosweb.es/libro/bootstrap_3/capitulo_6/paginadores.html and order it alphabetically.A greeting
C

Information from Nodejs/Gulp
Software Programming • node.js gulp consol • • charlenef

2

0
Votes

2
Posts

0
Views

N

If you use npm or yarn, you can write in packaje.josn in your violin bag. Let's say:... "scripts": { "build_dev": "gulp build --dev >> _log/gulp.log & type _log/gulp.log", "build_prod": "gulp build --prod", ... }, ... After what, just call. npm run build_dev♪ https://docs.npmjs.com/cli/run-script.html https://yarnpkg.com/ru/docs/cli/run/
Express Validator Custom - NodeJS
Software Programming • javascript node.js • • Analeea

2

0
Votes

2
Posts

0
Views

R

Hello! Express-validator maintainer here You must use promises to make your asynchronous validator in the express-validator.It would be more or less like this:.custom((emailRegistro) => { return new Promise((resolve, reject) => { accountModel.VerificarEmailExistente(sql, emailRegistro, (error, result) => { if(result.length !== 0){ reject(new Error('Email em uso')); } else { resolve(); } }); }); }) P.S.: validators .custom() use message Error released. So you don't have to use .withMessage() after him.
D

Browse for a JSON Nodejs
Software Programming • javascript json nodejs • • derk

2

0
Votes

2
Posts

0
Views

P

data is an array, so with any way to go through an array, you can access children, one of the most common forms is with a for in or with a foreach. When you say saving it in variables, I don't understand you very well. But I think the problem is that you've never worked with JSON. I'll put your code on you so you can see it a little clearer. const x = res.json(y que aquí la recibo no? de la llamada un api) // weno imagino algo como ... console.log(x.object) // te muestra por consola, list const y = x.data; // aquí accederías a data. for(let i =0; i > y.length; i++ ){ const dato_en_data = y[i]; console.log(dato_en_data.id, dato_en_data.object); // mostraría el id y el object de cada resultado. } I hope I helped you and cleared you a bit like JSONs or javascript objects work.
M

Additional investment in tag
Software Programming • javascript • • meriah

2

0
Votes

2
Posts

0
Views

S

<h3/> - is not a closing up.var a = 5; var b = 9; var result; document.writeln("<h3>Сумма</h3>"); result = a + b; document.write("<p>a + b = ", result, "</p>");
N

Receipt of the Y coordinates from the start of the site to the end or the loudslider for the video player
Software Programming • javascript html cs • • Nykeriab

2

0
Votes

2
Posts

0
Views

G

Look at the source code for other players, I created three functions UpdateVolume, GetPositions, GetVolume. And got a shotgun number that matches video.volume. UpdateVolume: function(ev, el, player, volumeline, volumelinediv){ var VolumePx = (1 - this.GetVolume(ev, el).y); var VolumeLineHeight = parseInt(getComputedStyle(volumeline).height); var VolumeLineDivHeight = parseInt(getComputedStyle(volumelinediv).height); var Volume = 1 - (VolumeLineDivHeight * VolumePx) / (VolumeLineDivHeight - VolumeLineHeight); player.volume = Math.max(0, Volume); if(VolumeLineDivHeight * VolumePx >= VolumeLineDivHeight - VolumeLineHeight){ return; } volumeline.style.top = Math.max(0, VolumeLineDivHeight * VolumePx) + 'px'; console.log( ); }, GetVolume: function(ev, el){ var Object = { top: this.GetPositions(el).top, left: this.GetPositions(el).left, width: el.clientWidth, height: el.clientHeight }; var Event = { pageX: ev.pageX, pageY: ev.pageY }; if(ev.changedTouches){ Event = { pageX: ev.changedTouches[0].pageX, pageY: ev.changedTouches[0].pageY }; } var y = (Math.max(0, Math.min(1, (Object.top - Event.pageY + Object.height) / Object.height))).toFixed(2); var x = (Math.max(0, Math.min(1, (Event.pageX - Object.left) / Object.width))).toFixed(2); return { y: y, x: x }; }, GetPositions: function (el) { var element = void 0; if(el.getBoundingClientRect() && el.parentNode){ element = el.getBoundingClientRect(); } if(!element){ return { top: 0, left: 0 }; } var doc = document.documentElement; var body = document.body; var ClientLeft = doc.clientLeft || body.clientLeft || 0; var ClientTop = doc.clientTop || body.clientTop; var ScrollLeft = doc.pageXOffset || body.scrollLeft || 0; var ScrollTop = doc.pageYOffset || body.scrollTop; var Left = element.left + ScrollLeft - ClientLeft; var Top = element.top + ScrollTop - ClientTop; return { top: Top, left: Left }; }
C

Height x Width - JavaScript - External Image
Software Programming • javascript jquery • • courtlanda

2

0
Votes

2
Posts

0
Views

P

Can use new Image ( https://developer.mozilla.org/en-US/docs/Web/API/HTMLImageElement/Image )To catch the original width and height of the image use:naturalWidthnaturalHeightAs described in https://developer.mozilla.org/en-US/docs/Web/API/HTMLImageElement Example:function getImageSize(url, success, error) { var img = new Image; img.onload = function () { success(img.naturalWidth, img.naturalHeight); }; img.onerror = error; img.src = url; } getImageSize("https://i.stack.imgur.com/ShnZP.png?s=328&g=1", function (largura, altura) { console.log("largura: " + largura, "altura: " + altura); }, function () { console.log("Erro ao carregar a imagem"); }); getImageSize("https://cdn.sstatic.net/Sites/br/img/sprites.svg?v=554232ea0d79", function (largura, altura) { console.log("largura: " + largura, "altura: " + altura); }, function () { console.log("Erro ao carregar a imagem"); });If you want to take the size of an image already entered on the page, you can use document.getElementByID or document.querySelector (depends on how the image is), for example:function getHtmlImageSize(img, success, error) { if (img.complete) { complete(); return; } img.addEventListener("error", fail); img.addEventListener("load", complete); function complete() { if (img.naturalWidth) { success(img.naturalWidth, img.naturalHeight); } else { error(); } finish(); } function fail() { error(); finish(); } function finish() { img.removeEventListener("error", error); img.removeEventListener("load", complete); } } //Pega a imagem no HTML var img1 = document.querySelector(".some-class > img"); getHtmlImageSize(img1, function (largura, altura) { console.log("largura: " + largura, "altura: " + altura); }, function () { console.log("Erro ao carregar a imagem"); });<div class="some-class"> <img src="https://i.stack.imgur.com/ObF0n.gif"> </div>

LevelDB in NodeJS

Suggested Topics

JS: Why return returns undefined? Software Programming • javascript • • jules

Duda NodeJS, import modules Software Programming • nodejs • • yajahira

Is there a Web equivalent.Config in Angular 4/5? Software Programming • javascript angular typescript web.c languageonfig • • terrea

Socket Disconnect Nodejs Software Programming • javascript node.js soc languageket • • gionna

Repeat of element Software Programming • javascript vue.js • • emran

How to make an if according to 3 times clicked a button? Software Programming • javascript • • esther

To which this error is due in NodeJS Software Programming • nodejs • • Marcee

How do you use two kernels in nodejs? Software Programming • node.js • • Rossere

Organize board within modal Software Programming • javascript php html css datatables • • tahishae

Information from Nodejs/Gulp Software Programming • node.js gulp consol • • charlenef

Express Validator Custom - NodeJS Software Programming • javascript node.js • • Analeea

Browse for a JSON Nodejs Software Programming • javascript json nodejs • • derk

Additional investment in tag Software Programming • javascript • • meriah

Receipt of the Y coordinates from the start of the site to the end or the loudslider for the video player Software Programming • javascript html cs • • Nykeriab

Height x Width - JavaScript - External Image Software Programming • javascript jquery • • courtlanda

JS: Why return returns undefined?
Software Programming • javascript • • jules

Duda NodeJS, import modules
Software Programming • nodejs • • yajahira

Is there a Web equivalent.Config in Angular 4/5?
Software Programming • javascript angular typescript web.c languageonfig • • terrea

Socket Disconnect Nodejs
Software Programming • javascript node.js soc languageket • • gionna

Repeat of element
Software Programming • javascript vue.js • • emran

How to make an if according to 3 times clicked a button?
Software Programming • javascript • • esther

To which this error is due in NodeJS
Software Programming • nodejs • • Marcee

How do you use two kernels in nodejs?
Software Programming • node.js • • Rossere

Organize board within modal
Software Programming • javascript php html css datatables • • tahishae

Information from Nodejs/Gulp
Software Programming • node.js gulp consol • • charlenef

Express Validator Custom - NodeJS
Software Programming • javascript node.js • • Analeea

Browse for a JSON Nodejs
Software Programming • javascript json nodejs • • derk

Additional investment in tag
Software Programming • javascript • • meriah

Receipt of the Y coordinates from the start of the site to the end or the loudslider for the video player
Software Programming • javascript html cs • • Nykeriab

Height x Width - JavaScript - External Image
Software Programming • javascript jquery • • courtlanda