Hello! In this article I will tell you how in 5 minutes and several teams in the terminal to launch a smart money collection contract for their ICO on Ethereum. This essay will potentially save you tens of thousands of US dollars, since any programmer - and not a programmer too - will be able to run a pro-audited and secure smart contract (instead of paying $ 1?000 - $ 7?000 for development). In short, you can send money to this smart contract and get tokens for this ERC20.
 
 
We can say that this article is a collection of all the experience that I got by launching the ICO for my project. Smart contract...

If you were developing for the node.js platform, then you probably heard about express.js . This is one of the most popular lightweight frameworks used when creating web applications for a node.
 
 

 
 
The author of the material, the translation of which we publish today, suggests studying the features of the internal device of the express framework through analysis of its source code and consideration of an example of its use. He believes that the study of the mechanisms underlying the popular open-source libraries promotes a deeper understanding of them, removes the veil of "mystery" from them ...

 
Have you ever traced the runtime of your application? Do you know how many queries you make that gray endpoint, which? And how long are those cross-references calculated for a similar resource type from each entity page that needs to be returned to the query? Have you tried to measure how long you have to wait for the user because of the optional query fields that he adds from time to time? Have you ever wondered if you would parallelize these six queries to those two databases?
 
If anything above sounds interesting, or at least familiar - welcome to the cut.
 
chrome: ...

In this message, we will look at ways to connect collections in NoSQL databases mongodb, arangodb, orientdb and rethinkdb (in addition to being a NoSQL database, they also have a free version with a fairly loyal license). In relational databases, similar functionality is implemented using SQL JOIN. Despite the fact that CRUD operations in NoSQL databases are very similar and differ only in details, for example, in one database, create ({}) is used to create an object, on the other - insert ({}), and in third - save ({}), - the implementation of a sample of two or more collections in each database ...

 
 
Five months ago we published an NPM module for working with the new version of Yandex.Kassa, which was released in October 2017. Our module has got into the official documentation, and it has already been downloaded more than 1300 times.
 
 

 
 
On Habr, together with colleagues from Yandex, we are already they told about the experience of creating the module, but behind the scenes was our experience, which we got when faced with the integration of the payment system for Russian clients.
 
 
Therefore, today we want to tell you how for one of our domestic clients we switched from the integration of the analogous to us foreign analogues to Russian analogues, with what difficulties faced and how they solved them.
 
became the application Sellsay . It helps users develop negotiation ...

Problem
 
There is an application generated using create-react-app . You need to deploy it to github.io.
 

The problem is that Github Pages only works with static code and Jekyll.

here . You need to set the environment variable in the project settings on travis-ci.com  
keep-history - without this option, the repository will in fact be created every time anew (push -f) and it will be impossible to track the history. With him, everything will be pokommitno (roughly as I described it in the section "manual demo").  
local-dir - After the ...

Node.js ??? was recently released. This is the seventh major release of the platform. He, in October 201? will receive the status of LTS for three years. Usually the main releases of Node are released twice a year. One - in April, and the second - in October. The material, the translation of which we publish today, provides an overview of the main innovations of Node.js ??? in terms of developing server applications and security.
 
 

 
300 commits . Thanks to this, we now have error codes that are easier to verify than messages...

The new asynchronous async /await constructs appear in jаvascript look simpler than Promise, and, of course, much more readable than the "callback jungle". But one thing that bothered me was the use of try-catch. At first I thought that this was not a problem, but unfortunately I had to work with the API call chain, in which each API call had its own error message, which should have been prologized. Soon I realized that I was creating a "try /catch-jungle" which was no better than a "callback jungle".
 
...

Since the advent of Node.js, diagnostics have been improved in several stages, from debugging applications to deep analysis of performance. This time we will talk about strategies for using tools such as core dump debuggers, flame graphs, production errors and memory leaks.
 
 

 
The material is based on a transcript of the report by Nikolai Matvienko from Grid Dynamics from our December conference HolyJS 2017 Moscow.
 
https://github.com/nickkooper/nodejs-diagnostics-resources [/i]
 
 
 
We hope you will benefit ...

 
Introduction
 
On the wave of popularity (I hope that they are popular) Vue.js and Electron , a reasonable question arises, and how to make them work together. In this tutorial, I'll show you how to quickly install and configure a template for developing applications on Electron and Vue.js. And so proceed.
 
That we need
 
 

yarn
- batch manager, analog npm . I chose yarn, because I just like this tool, however you can use npm as well. How to install yarn 3rd3r3323. , and npm
tuta ;
 

vue-cli
...