Development-arkiv - Page 2 of 3

Managing multiple Python versions with multiple virtual environments

Posted on May 3, 2019 by Peter Andersson

Since I was used to use rvm to handle multiple ruby versions, and a .ruby-version file which automatically switched version for me, of course I […]

Development, Python

Updating dyndns automatically from Linux

Posted on May 2, 2019 by Peter Andersson

If you have an account at the eminent service dyndns.com, you can update it automatically from your host by using this method: Start by installing […]

Development, Network

Download EOD data from Yahoo Finance to a Python Pandas Dataframe

Posted on April 17, 2019 by Peter Andersson

If you use the Pandas DataReader and get this message: pandas_datareader.exceptions.ImmediateDeprecationError: Google finance has been immediately deprecated due to large breaks in the API without […]

Development, Python, Trading

Slack shortcuts and commands

Posted on April 12, 2019 by Peter Andersson

I can’t stand long articles so here’s a short bullet list: Searching in:channelname, in:name, from:username, from:me, has:link, has:star, has:emojiname, before, after, on, during Commands /remind […]

Development, Network

Creating a child theme in WordPress

Posted on April 6, 2019 by Peter Andersson

This is a no-nonsense instruction of how to create a child theme in WordPress. We create it from the existing theme “twentynineteen” 1. Create a […]

Development, HTML and CSS, PHP, Wordpress

Multiple select listboxes in Rails

Posted on March 29, 2019 by Peter Andersson

Since I think the documentation is lacking and I always have to rely on Stackoverflow every time I want to use it, I keep this […]

Development, Ruby on Rails

Creating your own tag helper in Rails

Posted on March 29, 2019 by Peter Andersson

Lets say you get sick and tired of writing this in your views: <div class=”field”> <%=form.label :location %> <%=form.text_field :location %> </div> and instead you […]

Development, Ruby, Ruby on Rails

Elegant menu transition in Bootstrap

Posted on March 27, 2019 by Peter Andersson

I like the fixed menu, that stays in place when your scroll the content, but I have seen a few websites do a cool transition […]

Development, HTML and CSS, Javascript

Setting up Apache with Letsencrypt certificates

Posted on March 25, 2019 by Peter Andersson

Since you need a domain name, and I almost always use dynamic domain services, I recommend setting up ddclient so that the dynamic DNS is […]

Apache, Development, Linux, Network

No thank you!

Posted on March 12, 2019 by Peter Andersson

Putting a server on the internet is today similar to walking alone at night in a part of the city you know nothing about, where […]

Development, Linux, Network

A standard HTML header

Posted on February 28, 2019 by Peter Andersson

You should specify a lot of things in your HTML header nowadays. Previously it was enough with some CSS and JS script includes. Now we […]

Development, HTML and CSS, Wordpress

Creating a DSL in Ruby

Posted on February 14, 2019 by Peter Andersson

Creating a Domain Specific Language has been on my TODO-list for a long time! Ruby is the perfect language for this task I have collected […]

Development, Ruby on Rails

Pythons argparse for dummies

Posted on January 11, 2019 by Peter Andersson

Python is a great language, but sometimes it makes life more complicated than necessary. I don’t know if this is because it’s heritage (C) or […]

Development, Python

Make your own Rails View helpers

Posted on November 14, 2018 by Peter Andersson

Rails helpers like image_url, link_to, form_with, fields_for etc are nifty little “macros” that makes your Rails code smaller and clearer. I mean, who doesn’t prefer […]

Development, HTML and CSS, Ruby on Rails

Asymmetric Key Cryptography

Posted on October 26, 2018 by Peter Andersson

I know, it’s a mouthful! I never thought I’d understand asymmetric cryptography, partly because I tend to stay away from REALLY complicated stuff, and partly […]

Development, Linux, Math

Bringing some order in your data files

Posted on October 8, 2018 by Peter Andersson

Lots of harddisk space leads to…. lots of files. Why throw stuff away when keeping it is so cheap? I always end up with a […]

Development, Linux, OSX, Video

Roadmap for 2018/2019

Posted on September 25, 2018 by Peter Andersson

Too many frameworks? Check. Too many tools? Check. Too many crossroads? Then use this roadmap. It will help you decide which path to take in […]

Ajax, Development, Git, HTML and CSS, Javascript, React, Tankar, Thoughts, Vue

Installing OpenCV 3.4.1 using Python 3 on Raspbian Stretch

Posted on September 11, 2018 by Peter Andersson

UPDATED OCT 2020 See this link for a much better procedure: https://medium.com/@aadeshshah/pre-installed-and-pre-configured-raspbian-with-opencv-4-1-0-for-raspberry-pi-3-model-b-b-9c307b9a993a This is left for archiving purposes: As usual, I will keep this […]

Development, Python, Raspberry Pi

Array is an instance of class Class

Posted on September 3, 2018 by Peter Andersson

If the title to this post seems impossible to understand, please read this conversation between Gavin Sinclair and Martin de Mello. Something that was really […]

Development, Ruby, Ruby on Rails

What the heck is npx?

Posted on August 29, 2018 by Peter Andersson

If you haven’t lived under a rock for a couple of years, you must have stumbled upon npm, the standard node package manager, in one way […]

Development, Javascript, Node

10 common GIT problems and how to solve them

Posted on August 27, 2018 by Peter Andersson

Wish I had this list a couple of years ago! https://dev.to/citizen428/10-common-git-problems-and-how-to-fix-them-234o

Development, Git

Controlling an USB camera from a Raspberry Pi, and doing some image magic! (Part1)

Posted on August 2, 2018 by Peter Andersson

The Raspberry Pi is a fantastic piece of equipment, and what I like the most is that it resembles a standard computer with Ubuntu, just […]

Development, Python, Raspberry Pi, Video

The best CSS Grid reference page!

Posted on July 22, 2018 by Peter Andersson

A Complete Guide to Grid A great example of how to use Grid CSS to show thumbnails https://codepen.io/SitePoint/pen/JBqgGm

Development, HTML and CSS

Where’s the action?

Posted on July 14, 2018 by Peter Andersson

There are so many web frameworks. And their supporters all claim that “their” framework is the one with the most momentum. The site http://hotframeworks.com tries […]

Ajax, Development, Javascript, React, Vue

Gulp or Webpack?

Posted on June 14, 2018 by Peter Andersson

First of all, Gulp and Webpack are not beasts of the same kind. Gulp is a task runner, which you can use for various tasks […]

Development, Javascript, Ruby on Rails

Screen scraping using the Mechanize gem

Posted on June 13, 2018 by Peter Andersson

What do you do, when you want to extract some data from a system, but there is no neat API for that particular service? Well […]

Development

Design Patterns

Posted on June 13, 2018 by Peter Andersson

Introduction Design Patterns are an important power tool in your toolbox. You will fall back on these trusty patterns again and again, knowing that you […]

Development, Patterns

Pimp your Rails site with some Vue.js

Posted on June 7, 2018 by Peter Andersson

Rails is great, but nowadays a full page refresh is as unpopular as male ponytails or shoulder pads. Some write full-stack SPA sites, which is […]

Ajax, Development, HTML and CSS, Javascript

Gulp or Grunt?

Posted on June 7, 2018 by Peter Andersson

OK, let’s have it, are you a Gulper or a Grunter? To some, build systems are a major issue. To me, not so much. In […]

Development, HTML and CSS, Javascript, Thoughts

User sign-in from SPA to Rails backend

Posted on May 29, 2018 by Peter Andersson

Intro Nowadays it is popular to create fullstack-JS applications (meaning both front- and backend written in Javascript) but what if you want to use the […]

Ajax, Development, Javascript, Ruby on Rails

Saving nested models in Rails

Posted on May 23, 2018 by Peter Andersson

Very often, I would say almost always, you have nested models in a Web application. In Rails, you (most often) specify it using has_many and […]

Development, Ruby on Rails

What makes Rails a framework worth learning in 2017?

Posted on May 16, 2018 by Peter Andersson

From Quora: https://www.quora.com/What-makes-Rails-a-framework-worth-learning-in-2017 David Heinemeier Hansson, Creator of Ruby on Rails, Founder & CTO at Basecamp The same reasons why it was a framework […]

Development, Ruby on Rails

Simple Ajax in Rails 5.2

Posted on May 15, 2018 by Peter Andersson

I’d like to present a short and to-the-point instruction on how to add some Ajax pizazz to a simple Rails-generated page. It won’t take you […]

Ajax, Development, Ruby on Rails

Spring Boot

Posted on April 27, 2018 by Peter Andersson

Almost 5 years ago (time flies!) Phil Webb and Dave Syer wrote a blog and twitter entry that boiled down to this: @Controller class ThisWillActuallyRun […]

Development, Java

Common Rails error you will (most probably) see in your log file

Posted on April 26, 2018 by Peter Andersson

Phil Nash wrote a great article about common Rails errors and how to deal with them. The common errors are: 1. ActionController::RoutingError 2. NoMethodError: undefined […]

Development, Ruby on Rails

Adding a new website under Apache

Posted on April 18, 2018 by Peter Andersson

Apache Apache is a great piece of website software. What I like the best, is that it is mature and reliable. It is also easy […]

Apache, Development, Linux, Wordpress

Good WordPress themes

Posted on April 18, 2018 by Peter Andersson

Divi (https://www.elegantthemes.com) $89/år eller $249 lifetime fee OceanWP Enfold $59 (https://themeforest.net/item/enfold-responsive-multipurpose-theme/4519990)

Development, Wordpress

Useful Linux commands

Posted on April 3, 2018 by Peter Andersson

Note: All commands must be prefixed with “sudo” in case your user account doesn’t have enough privileges. System $ uname -a Displays Linux system information […]

Development, Linux, Network

Java 11 is here!

Posted on March 28, 2018 by Peter Andersson

In accordance with the new policy of releasing a new Java version every 6 months, we now have a fresh installation of Java 11 to […]

Development, Java

Don’t like Java? Create your own language!

Posted on March 26, 2018 by Peter Andersson

Nowadays, it’s easier than ever to create your own computer language. Whether it’s a simple rule-system, or a full-blown language, you can create the tokenizer […]

Development, Java, Thoughts

Using microservices when building large-scale systems

Posted on March 25, 2018 by Peter Andersson

Microservices, when supported by a robust framework, is a incredibly productive way of building large-scale services. You get a lot of support from the framework, […]

Development, Google, MIcroservices, Microsoft

Installing Oracle Java 9 on OSX/macOS

Posted on March 8, 2018 by Peter Andersson

For macOS/OSX all you need to do is download and run the DMG from http://www.oracle.com/technetwork/java/javase/downloads/jdk9-downloads-3848520.html

Development, Java, OSX

Saving GIT passwords

Posted on February 28, 2018 by Peter Andersson

Saving your git password lets you skip giving username/password at every checkin Normally you use git config –global credential.helper store but this is not very […]

Development, Git, Linux

Setting up MYSQL, Apache2 and WordPress

Posted on February 26, 2018 by Peter Andersson

MySQL/MariaDB Remember to change bind-address to 0.0.0.0. By default it is set to 127.0.0.1 and then you can’t connect remotely! Exactly which config file it […]

Apache, Development, Linux, MySQL, Network, Wordpress

SSH Login without password

Posted on February 24, 2018 by Peter Andersson

http://www.linuxproblem.org/art_9.html Basically you add the content of your own ~/.ssh/id_rsa.pub to the targets ~/.ssh/authorized_keys file. (Replace ‘a’ with your username, A with your hostname or […]

Development, Linux, Network

Setting up Oracle Java 9 on Ubuntu

Posted on February 23, 2018 by Peter Andersson

Since Oracles own instructions (https://docs.oracle.com/javase/9/install/installation-jdk-and-jre-linux-platforms.htm) sucks big time, I can recommend this one instead: https://www.digitalocean.com/community/tutorials/how-to-install-java-with-apt-get-on-ubuntu-16-04 Simple and easy to follow. And it WORKS!

Development, Java, Linux

Javascript frameworks 2018

Posted on February 22, 2018 by Peter Andersson

Some alternatives to Angular 1.x (deprecated), Angular 2 (Typescript) and Angular v4 https://www.slant.co/topics/4306/~angular-js-alternatives vue.js riot react (not a framework, per se. It’s a view rendering […]

Development, Javascript

What you need to know about AWK

Posted on February 20, 2018 by Peter Andersson

General structure BEGIN { print “BEGIN” } /filter1/ { print $0 } /$6 == “Nov”/ { print $1, $2 } […]

Development, Linux

Why Ruby is Great!

Posted on February 19, 2018 by Peter Andersson

The single reason why I started dating Ruby class VCR def initialize @messages = [] end def method_missing(method, *args, &block) @messages << [method, args, block] […]

Development, Ruby on Rails

Fancy Pancy Tech Talk

Posted on February 17, 2018 by Peter Andersson

You can find a lot of business terms here https://en.wikipedia.org/wiki/List_of_business_terms https://en.wikipedia.org/wiki/List_of_buzzwords Churn Rate Churn rate, when applied to a customer base, refers to the proportion […]

Development, Thoughts

Rails relations

Posted on February 16, 2018 by Peter Andersson

problem You know when you want to select records depending on the values of related records (like belongs_to fields) ? scenario class TradingSignal < ActiveRecord::Base […]

Development, Ruby on Rails

Rails HATM (Has and belongs to many)

Posted on February 12, 2018 by Peter Andersson

Nested forms with HABTM and HasManyThrough Start with the models has_many :events # creates …… accepts_nested_attributes_for :events, :allow_destroy => true # creates…. attr_accessible :events_attributes # […]

Development, Ruby on Rails