SEARCH KEYWORD -- PROGRESSIVE WEB APP TECHNOLOGY


  Why localStorage only allows to store string values

localStorage allows data to be stored in browsers across sessions, the data will be there even though the session is expired. It is frequently used to store static data so that they can be loaded when needed. But as per spec, it says that the keys and the values are always strings (note that, as with objects, integer keys will be automatically converted to strings). Why cannot store the object as it is? Take a look at an example: var str = "test"; localStorage.setItem("str", str); cons...

   JAVASCRIPT,LOCALSTORAGE     2020-04-05 00:54:29

  How to play with cross domain request

What is cross domain request In simple, cross domain request is to request resource from other domain in one domain. Note, the "other domain" doesn't just mean domain name only, it includes much more. If the protocol, domain name, port is not the same, two domains will be considered different.  Below example describes what is considered as different domain. http://www.a.com/a.jshttp://www.a.com/b.js               # Same domainhttp://www.a.com/lab/a.js &nb...

   FRONT END,JSONP,CROSS DOMAIN,CROSS ORIGIN,CORS,DOCUMENT.DOMAIN,WINDOW.NAME     2016-11-06 00:48:54

  trim() in JavaScript

In the past, JavaScript didn't define the trim() function for String object. This makes web programmers frustrated since they often need to implement this function themselves if they want to handle user inputs. The new version of ECMA-262 introduces the trim() function.15.5.4.20   String.prototype.trim ( )     The following steps are taken:     1.   Call CheckObjectCoercible passing the this value as its argument.   2.   Let S...

   JavaScript,trim(),implementation     2012-07-19 10:58:01

  Jackie the smart quadcopter to launch at Robotics Week

Flying security camera synced to smartphone kicks off Kickstarter campaign Entrepreneurs and robotics graduate students Jackie Wu and Ritwik Ummalaneni, in Northwestern University’s Master’s in Robotics program, are launching their new product, Jackie, during the National Robotics Week. The flying security camera quadcopter syncs straight to a smartphone, and is the next evolution in home security platforms that consumers have been waiting for. Jackie’s intuitive and easy co...

   Startup,Quadcopter,Security camera,Jackie Wu     2015-04-05 20:56:11

  Deep clone of JavaScript object

In JavaScript world, it's frequently seen object clone. Normally when creating a clone of an object, it's only the reference being cloned but not all contents. In some scenarioes, it's desired to clone all the content instead of just the reference such that any change made to the cloned object will not change the original object. Differences between shallow clone and deep clone can be as simple as: Shallow clone : Only the object reference is cloned but not the content Deep clone : Clone all co...

   JAAVSCRIPT,DEEP CLONE,DEEP COPY,SHALLOW CLONE,SHALLOW COPY     2016-10-31 00:27:24

  Why is Golang's Compilation Speed So Fast?

Overview When I started learning the Go language, I already had experience with three statically typed languages—C/C++ and Java—and two dynamically typed languages—PHP and JavaScript. Because of this background, when I compiled a demo file of several hundred lines for the first time in Go, I was genuinely impressed by its compilation speed. At that moment, I thought to myself, "Go claims to have the execution speed of statically typed languages and the compilation speed of dyna...

   GOLANG,COMPILATION,GO     2024-10-07 22:02:23

  Understanding PGO in GoLang 1.20

Background The Go 1.20 version was officially released in February 2023, it introduced the PGO(Profile Guided Optimization) mechanism. The basic principle of PGO can be divided into the following two steps: First, profiling is performed on the program to collect data about the program's runtime and generate a profiling file. When compiling the program, enable the PGO option, and the compiler will optimize the program's performance based on the content in the .pgo file. When compiling a program...

   GO 1.20,PGO,GOLANG     2023-02-28 04:27:46

  Python SSH Connection Tools

Program Design Purpose: We aim to create a simple Python SSH tool library that facilitates SSH communication, SCP file transfer, and SSH port forwarding through multiple jump hosts in an SSH tunnel chain. The library is designed to provide a simple API for establishing nested SSH tunnel connections through multiple jump hosts with customizable TCP ports. This allows users or their programs to automate SSH tasks such as: Batch processing SSH connection tasks, such as connecting to multiple ser...

       2024-08-30 04:46:05

  Best practices of front end optimization

1. Use DocumentFragment or innerHTML to replace complex elements insertion DOM operation on browser is expensive. Although browser performance is improved much, multiple DOM elements insertion is still expensive and will affect the page load speed. Assume we have an ul element on our page, we now want to retrieve a JSON list using AJAX and then update the ul using JavaScript. Usually we may write it as : var list = document.querySelector('ul'); ajaxResult.items.forEach(function(item) { // ...

   JavaScript,Front end,Optimization,Tips     2013-07-06 11:26:27

  A tutorial on Github Actions

Github Actions is a CI/CD service created by Github. It aims to make it easy to automate all software workflows, now with world-class CI/CD. Build, test, and deploy code right from GitHub. It was launched in October 2018 and was officially available to all users in November 2019. This post will give an introduction of Github Actions and explain how it works. What is Github Actions Normally Continuous Integration includes some steps, fetching code, running test, sshing into remote server in...

   GITHUB,GITHUB ACTIONS,CI,CD     2019-12-23 05:33:39

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