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Showing posts from April, 2020

Node.js MongoDB Queries

Queries We will learn how to to find the data from the database in this tutorial. To find documents in a collection we can filter the results using the query object. This query object is passed as the first argument of the  find()  method. We can limit the search with the help of this query object.  If you have not learned about how to create a collection in  MongoDB with Node.js  and place the documents in that collection with node JS, then  read the previous tutorial .  This tutorial includes The find() method Query Object AND query OR query Conditional queries Regular Expression Query Special Query Options Querying inside Objects and Arrays Query Options Paging Sorting The find() method The syntax of the  find()  method on  Collection  is, collection . find ( query [ [ [ , fields ] , options ] , callback ] ) ; The  “query”  is an object representing query and specifying ...

Browser-Based Eye Tracking

recent years computer vision has drastically evolved and has been widely available to programmers with open libraries such as  OpenCV . OpenCV offers image manipulation capabilities in order to extract information from images, like classification of objects, face characteristics and body poses, in a way that computer sees what we see in real time -thus computer vision. At the same time, programming languages have become way more powerful tools and easier of use. Nowadays, for example, Python programming language does literally everything, requires small amounts of coding and runs in any environment, from a huge google cloud server to a “potato” in your basement. Python owes its huge success to its very strong community that produces a wide variety of libraries with many features and functionalities. However, a drawback is that Python is not easy to be run on a browser and it is usually run server side communicating with the browser with web services. Hence, that could produce a...

Creating a CRUD API with Node, Express, and gRPC

Speed is becoming increasingly valuable in the web world. Developers launching new releases of softwares, frameworks and libraries have certainly invested a lot of time in decreasing numbers regarding loading time, request processing, and resources consuming. HTTP/2 , for example, was born through a myriad of optimizations that led the web to a more robust, faster, and lighter zone than we’ve ever been before. The RPC (that stands for Remote Procedure Call) is a well-known way to get traction when you need to be a bit remote or distributed. In the era of enterprise servers and complicated massive amounts of code needed to set things up, it used to reign. After years of isolation, Google redesigned it and has put new light into it. gRPC  is a modern open source high performance RPC framework that can run in any environment. It can efficiently connect services in and across data centers with pluggable support for load balancing, tracing, health checking, and authentica...