Adjusting Mouse Scroll Speed in Mac OS Sierra

For many people, the default range of mouse scrolling speeds offered in the Mac OS System Preferences tab does not offer fast enough tracking speeds, especially on larger screens. In previous releases of Mac OS X, 3rd party preference tabs could be used to allow faster speeds and other formsof customisation (including mouse acceleration). Unfortunately, with the release of Mac Os Sierra, several of the internal calls used by these 3rd party utilities were removed, disabling their functionality.

There is still a way to enable faster mouse scroll speeds in Mac OS Sierra though, as detailed in this Apple Support article.

The new process is as follows:

  1. From the Apple menu, choose System Preferences.
  2. From the System Preferences window, select Accessibility.
  3. In the left sidebar, select Mouse & Trackpad.
    System Preferences
  4. Click the Mouse Options button.
  5. In the sheet that appears, use the slider to adjust the mouse scrolling speed, including acceleration.
    Scrolling Speed in System Preferences

 

The “Mouse & Trackpad” accessability panel sheet gives quite a few good options, although still not as many as some of the 3rd party preference utilitities did.

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Avoiding multi-table inheritance in Django Models

Model inheritance does not have a natural translation to relational database architecture and so models in Django should be designed in order to avoid impact on database performance. When there is no need for the base model to be translated into a table abstract inheritance should be used instead of multi-table inheritance.

Given the following model:

class Person(Model):
  name = CharField()
  …

class Employee(Person):
  department = CharField()
  …

Two tables will be created and what looks like a simple query to the Employee child class will actually involve a join automatically being created. The same example with abstract = True in the Meta class allows abstract inheritance:

class Person(Model):
  name = CharField()
  …

class Meta:
  abstract = True

class Employee(Person):
  department = CharField()
  …

By putting abstract = True, the extra table for the base model is not created and the fields within the base model are automatically created for each child model. This avoids unnecessary joins being created to access those fields. This way of using model inheritance also avoids repetition of code within the child classes.

How to Install Apache Tomcat on Mac OS Sierra

Our previous tutorial on installing Tomcat on El Capitan had a lot of interest, so here it is an updated (but broadly similar) tutorial for MacOS Sierra.

In this tutorial, we will be using the open-source package manager Homebrew. If you’re not already using homebrew, check out its popularity on GitHub. It’s highly recommended for use with developing on Macs as it makes keeping track of installed software 100 times cleaner than doing it manually (everything is stored in one place, packages are easy to remove, upgrade and find configs for).If you don’t already have Homebrew, install it with:

First, open your Mac terminal window. If you don’t already have Homebrew, install it with:

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"


Step 1: Install Tomcat

Now we can easily install and track the version of Tomcat we’re using and config files etc with the following command:

brew install tomcat

This will take care of the downloading, installation and configuration of Tomcat and manage its dependencies as well. Take note of the output, brew commands are typically really good at displaying concise but useful info, errors and other help.

Homebrew keeps all installed packages (called “kegs”) in a “Cellar” folder – they like their beer references. By default, this is located in the /usr/local/ directory, so there should now be a tomcat folder listed by the command:

ls /usr/local/Cellar

Although an easier shortcut is available as:

brew list

To get more info on Tomcat specifically:

brew list tomcat

This should output something similar to:

$ brew list tomcat
/usr/local/Cellar/tomcat/8.5.15/bin/catalina
/usr/local/Cellar/tomcat/8.5.15/libexec/bin/ (15 files)
/usr/local/Cellar/tomcat/8.5.15/libexec/conf/ (10 files)
/usr/local/Cellar/tomcat/8.5.15/libexec/lib/ (25 files)
/usr/local/Cellar/tomcat/8.5.15/libexec/temp/safeToDelete.tmp
/usr/local/Cellar/tomcat/8.5.15/libexec/webapps/ (573 files)
/usr/local/Cellar/tomcat/8.5.15/RELEASE-NOTES
/usr/local/Cellar/tomcat/8.5.15/RUNNING.txt

The listed binary file Catalina is the “servlet container” used to run the Apache Tomcat server. This can now be started using the command:

catalina run &

The ampersand at the end makes the process run in the background, so after pressing the return key you get your terminal back but Catalina is still running in the background, you can remove it if you want to keep a dedicated window on the process.

Catalina can be stopped using:

catalina stop

 

Step 2: Configure Tomcat

Apache Tomcat comes with an inbuilt GUI management suite, however, for security reasons, this is disabled by default (to avoid dangerous default usernames/passwords). To enable the GUI manager, first edit the file:

nano /usr/local/Cellar/tomcat/8.5.15/libexec/conf/tomcat-users.xml
  • Nano is a text editor that comes with MacOS, although any will do.
  • If the file is blank or not found, you probably have a slightly different version of Tomcat installed, hit ctrl + x to exit, then run the command brew list tomcat and replace the above version number with the one you have installed.

Scroll to the bottom of the file and you should see several user entries surrounded such as:

<!–
<role rolename=”tomcat”/>
<role rolename=”role1″/>
<user username=”tomcat” password=”<must-be-changed>” roles=”tomcat”/>
<user username=”both” password=”<must-be-changed>” roles=”tomcat,role1″/>
<user username=”role1″ password=”<must-be-changed>” roles=”role1″/>
–>
</tomcat-users>

The <!– …  –> means these users are commented out. Leave them as they are and add a new entry after but above the </tomcat-users> line with the “manager-gui” role:

<user username=”someUser” password=”somePassword” roles=”manager-gui”/>

So the file now looks like:

<!–
<role rolename=”tomcat”/>
<role rolename=”role1″/>
<user username=”tomcat” password=”<must-be-changed>” roles=”tomcat”/>
<user username=”both” password=”<must-be-changed>” roles=”tomcat,role1″/>
<user username=”role1″ password=”<must-be-changed>” roles=”role1″/>
–>
<user username=”someUser” password=”somePassword” roles=”manager-gui”/>
</tomcat-users>

Obviously, you should use a unique username & password for security!

Now, start Catalina again:

catalina run
  • If you get errors, you probably need to stop it first, use catalina stop
  • By default, Tomcat runs on port 8080. There’s a really useful command to see what services are running on this a port: lsof -i :8080 (you may need to prefix with sudo for admin protected ports like 80).

Now if you go to the following page you should see a management GUI:

http://localhost:8080/manager/html

Here you can deploy .war files or exploded directories using the Deploy console and existing servlets are listed. You can even try visiting the already deployed servlets by appending the listed path to localhost:8080 (the default tomcat port):

So, the following should give the docs & some examples:

http://localhost:8080/docs
http://localhost:8080/examples

Enter the .war file location you wish to deploy and the desired path into the Deploy section and your application should now be listed as running with its path. Additionally, this can be used with an IDE like Netbeans or IntelliJ to run & debug servers using their configuration windows.

Any questions, please ask in the comments, and please share this article if you found it helpful.

PBCopy Mac command

A couple of useful Mac terminal (or iTerm) commands are the PBCopy & PBPaste. Here is a demonstration of how they work.

There are two basic ways to copy using pbcopy:

$ pbcopy < source_file.txt
copies text in source_file.txt

$ pwd | pbcopy
copies the output from pwd (the current directory) to the Mac clipboard

The copied text can now be pasted (either using menu’s or the CMD + V keyboard shortcut) into other applications in the usual way.

PBPaste works using the same syntax but in reverse:

$ pbpaste > destination_file.txt
pastes the current Mac clipboard to destination_file.txt

$ cd `pbpaste`
change directory to what's is currently stored in Mac clipboard

npm start error – TypeError: Path must be a string. Received undefined

This is a common generic error received whilst attempting to run older typescript based projects still using the now deprecated TSD package manager, on a system using TSD’s replacement Typings.

tl;dr  I just want to get this thing running quickly:
Installing (the deprecated) TSD package manager is often fastest way to get around these backward compatability issues:

$ npm install tsd -g

[disclaimer]using deprecated software is bad, see below for real fixes![/disclaimer]

 

Ok, now let’s look at actually fixing the problem.Unfortunately, the error’s output can be rather ambiguous, generic and difficult to get much helpful info from:

$ npm start

> node start.js
ts-loader: Using typescript@1.8
webpack built [...hash] in 1ms

ERROR in ./src/index.tsx
Module build failed: TypeError: Path must be a string. Received undefined
at assertPath (path.js:7:11)
at Object.dirname (path.js:1324:5)
at ensureTypeScriptInstance (/[...project src dir]/index.js:156:103)
at Object.loader (/[...project src dir]/node_modules/ts-loader/index.js:375:14)
@ multi main

 

Suspecting the error may be due to the project having been created using TSD rather than Typings, with the project having a tsd.json file rather than a typings.json file.

TSD has now been deprecated in favor of Typings, but the quickest way to get the project running is to install TSD, however this is obviously not ideal for anything but quickly checking out a project.

The Typings website provides info on how to upgrade from TSD to Typings, here:
https://github.com/typings/typings/blob/master/docs/tsd.md#upgrade

The official deprecation notice on the TSD GitHub page provides some more useful info and background too:
https://github.com/DefinitelyTyped/tsd/issues/269

A potential confusion is that the tsconfig.json remains the same name (although some parameters may need altering, moved file references updated/deleted), now the tsd.json is called typings.json with a similar config, but potentially also in need of manual editing after running the basic Typing’s upgrade process.

But hopefully, running npm start should work:

$ npm start
Compiled successfully!

The app is running at:

 http://localhost:3000/

 

If this does not work, a couple of additional steps may be required, including (but not limited to):

  • If a webpack compile errors say “Module build failed: Error: ENOENT: no such file or directory,” you should check your tsconfig.json file is not referencing any old tsd files which no longer exist (usually in the project’s typings/ directory).
  • You may need to create a tsconfig.json file in your project root directory (i.e. usually same one as package.json etc) if you do not already have one, visit the Typescript language homepage for more info. (Courtesy of https://www.garysieling.com/blog/fixing-webpack-error-path-must-string-received-undefined)
  • You may need to upgrade one or more old npm dependencies in your package.json file. Tools like npm-check-upgrades can help (use npm-check-upgrades -u to actually install the newer package versions – warning: may break the application).
  • Try suggestions from the above links, (e.g. the TSD deprecation announcement).
  • If all else fails, undo everything so far (if a git repo type:
    $ git checkout — .
    ) and install the TSD package manager (deprecated and bad, but a potential short-term workaround):
    $ npm install tsd -g

 

These package upgrade errors do seem to happen with a regular frequency, but are usually solvable with a bit of work. If the above solutions did not work for you or you have succeeded using another, please let others know about it in the coments.

Programming Cheat Sheets

Great collection of programming language cheat sheets listed in this article.

Nice just to browse them all for fun.

As a follow-up question, what opinions do people have on cheat sheets in aid of teaching or learning new skills? I’ve always found them a great tool but many other teachers proclaim that they’re flawed.

Comments & opinions welcome.

Node-inspector console not working in latest version of Google Chrome

The latest version of Google Chrome doesn’t execute commands when the Enter button is pressed and instead just wraps to a new line. Instead of downgrading Chrome, a quick fix appears on the node-inspector issue list here.

Quick Fix

Edit node-inspector’s config file (below is global npm installation path, local in project’s node_modules directory):

$ nano /usr/local/lib/node_modules/node-inspector/front-end/platform/DOMExtension.js

Search for the isEnterKey function (line 779) and comment out the line:
return event.keyCode !== 229 && event.keyIdentifier === "Enter";
Replacing it with:
return (event.keyCode !== 229 && event.keyIdentifier === "Enter") || event.keyCode === 13;

So the function now looks like:

function isEnterKey(event) {
    return (event.keyCode !== 229 && event.keyIdentifier === "Enter") || event.keyCode === 13;

    // Check if in IME.
    // return event.keyCode !== 229 && event.keyIdentifier === "Enter";
}

Save, restart node-inspector and your node process manager (e.g. nodemon, pm2 etc) and node-inspector once again executes console commands via the Enter key.

Using Auth0 with Symfony

Auth0 provide a 3rd party authentication service, as they point out this can have a lot of benefits (along with a few drawbacks). They have written a great tutorial on integrating Auth0 with the PHP Symfony framework here:

https://auth0.com/blog/creating-your-first-symfony-app-and-adding-authentication/

Do many people have experience using Auth0 to handle their authentication? I’ve never used them and am naturally sceptical about tying my platform to a 3rd party supplier I will have to pay. However it’s so frequent seeing a lot of expensive developer time wasted on an inferior inhouse solutions so is this worth a try?

Setup PHP Dev Environment on Mac OS X Sierra – Apache, MySQL & PHPMyAdmin

Getting the development environment right at the start is vitally important to productive application development. Here we will setup a flexible “LAMP” development environment on the latest Mac Os X, El Capitan. We will focus on keeping the development platform flexible and stable, centrally managing all system & application dependencies. Within a few minutes, we will hopefully have advanced PHP web applications serving up pages, but with the ability to integrate extra system components specific to your application.

System (optional)

Apple’s native development IDE is XCode, it’s not great for PHP but provides handy tools and installing it kind of tells Apple your computer’s being used for software development and to unlock related features. If you’re starting on a completely fresh system, it’s a good idea to install Apple’s Xcode tools. Open up the Terminal App, e.g. cmd + space then: terminal  and type:

sudo xcode-select --install
sudo xcodebuild -license

You will have to agree to some terms & conditions but prevents later problems using common tools like Git.

Install Apache and PHP7 (or other versions)

Install the amazing and free open-source Homebrew  package management system which will make open-source software development far more manageable. If you’re not yet convinced by Homebrew, check out its popularity on GitHub. Install Homebrew as such:

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

As of writing, the most recent version of PHP is 7.0, although Mac already has PHP and Apache inbuilt, we will install it using Homebrew to better manage all development services & dependencies – they’ll be all in one place, managed using a standard set of commands. Allowing us to easily upgrade & downgrade PHP, also since Apache (the web server / engine) keeps changing between MacOS releases, we will use Homebrew to manage and keep it consistent.

Fist stop the default Apache service, in the terminal type:

 sudo apachectl stop
 sudo launchctl unload -w /System/Library/LaunchDaemons/org.apache.httpd.plist 2>/dev/null
 brew install httpd24 --with-privileged-ports
 brew install php71
[short wait to download files]
 brew services start homebrew/apache/httpd24

This should take a minute or less and Homebrew is usually really good at providing helpful and clean output info, errors and ways to fix them. For example, it may give you info about where the php.ini file is, (e.g. /usr/local/etc/php/7.0/php.ini ) or suggest the following command to automatically start PHP7 at login:

 brew services start homebrew/php/php70

As mentioned, helpful and clean output info is one of Homebrew’s real strong points, always read what it outputs!

Verify PHP7 installation (optional)

These are a few really useful commands to check everything is working, or diagnose any problems:

Format:   command
                     output

    php -v

PHP 7.0.8 (cli) (built: Jun 23 2016 16:32:40) ( NTS )
Copyright (c) 1997-2016 The PHP Group
Zend Engine v3.0.0, Copyright (c) 1998-2016 Zend Technologies

    which php
/usr/local/bin/php

    ls -l /usr/local/bin/php
lrwxr-xr-x  1 maltronic  admin  36 30 Aug 19:20 /usr/local/bin/php -> /usr/local/Cellar/php70/7.0.8/bin/php

     php -i | grep php.ini
Configuration File (php.ini) Path => /usr/local/etc/php/7.0
Loaded Configuration File => /usr/local/etc/php/7.0/php.ini

If for any reason there’s a problem you can manually point php to the desired version. First, check what Kegs are have installed in your Cellar using:

brew list

If no version of php appears, try “tapping” homebrew to enable it to pick up more software kegs then installing php7 like so:

brew tap homebrew/dupes
brew tap homebrew/versions
brew tap homebrew/homebrew-php
brew install php70

You can link to whichever installed PHP version you like, say you wanted to use PHP 5.6 (and have installed it using brew install php56 then create a symbolic link to /usr/local/bin/php:

ln -s /usr/local/Cellar/php56/5.6.23/bin/php /usr/local/bin/php

Enable Debugging (optional)

Stop haphazardly print variables to the screen and become a real pro developer, use debugging! It’s so easy and better for fixing bugs. To install Xdebug and enable IDE debugging using popular IDEs like Netbeans and PHPStorm, install with homebrew:

brew install php70-xdebug

Install MySQL

Although MariaDB is slowly replacing MySQL in open source circles, either can be installed, as such:

brew install mysql

Just replace “mysql” with “mariadb” (for rest of article). The Homebrew MySQL/MariaDB server should now be running, this can be verified with:

brew services list

Typing just brew services lists the Homebrew’s service manager commands. If mysql isn’t already running, type brew services start mysql

Configure Apache

We will keep on using the preinstalled Apache server but edit the Apache config file to enable the PHP7 module. Use Mac’s inbuilt nano editor or another text editor (like Sublime Text):

sudo nano /etc/apache2/httpd.conf

Add the following line:

  LoadModule php7_module /usr/local/opt/php70/libexec/apache2/libphp7.so

Press ctrl + x to quit.

Now, every site we add will be a new VirtualHost in Apache, one of potentially many web applications running on your computer. Whilst you can edit the /etc/hosts file to enable local domain names, a quick and reliable technique is to use different ports to distinguish websites. First, make sure Apache is checking for Virtual Hosts and that there’s no # commenting out the file:

sudo nano /etc/apache2/httpd.conf

Go right to the bottom of the file (ctrl + v is PAGE DOWN) and ensure the following line does not have a # infront, it should look like the middle line below:

...

Include /private/etc/apache2/other/*.conf

...
(i.e. no #, although the * is ok)


Now edit Apache’s VirtualHost config file, using the nano editor command:

sudo nano /etc/apache2/extra/httpd-vhosts.conf

And add a VirtualHost config for your website:

Listen 81

DocumentRoot "/Users/maltronic/my_php_project/web"
ServerName "local.my_php_project"
ErrorLog "/var/log/apache2/my_php_project-error.log"



Options Indexes FollowSymLinks
AllowOverride All
Require all granted

Where the directory (“web” above) is the base directory that will appear on your website (i.e. where index.php or an equivalent would sit).

Now, finally, we restart the Apache server to apply our changes:

sudo apachectl restart

Some errors may appear (especially in regards to domain names), these generally don’t matter although if there’s an obvious problem stated you should fix it and re-run the restart command.

Install PHPMyAdmin

As usual, install PHPMyAdmin using Homebrew:

brew install phpmyadmin

And as usual, Homebrew will give some info on any final steps, which in my case means:

sudo nano /etc/apache2/httpd.conf

Then adding to the bottom of the file (ctrl + v is page down in nano):

Alias /phpmyadmin /usr/local/share/phpmyadmin

Options Indexes FollowSymLinks MultiViews
AllowOverride All

Require all granted


Order allow,deny
Allow from all

Install Composer (optional)

Composer is a near universally adopted PHP package manager that enables your PHP applications to use 3rd party libraries and manage their dependencies (very similar to Homebrew but for your PHP application (on any OS), rather than Mac Operating System).

It’s not needed yet, but most professional and open-source projects use it. For consistency let’s install it using Homebrew:

brew install composer

As usual, look at the screen output for any errors and info.

That’s It

Try loading PHPMyAdmin in a web browser at:

http://localhost/phpmyadmin

By default the MySQL admin user is: root (with no password).

You now have a fully functioning and extremely flexible LAMP development environment. From here you can easily add additional services like Redis, Memcache, RabbitMQ, other databases and whatever else you would like to use in your project


This guide gets updated based on reader comments. Any problems, please comment below or share on social media if you found this guide useful!

PyCharm Auto-import works differently to PHPStorm and IntelliJ

Having become used to developing in JetBrain’s PHPStorm & IntellliJ IDEs it nows seems tedious to break out of the programming flow to manually type out imports every time we introduce a new dependency.

However in that company’s Python IDE, PyCharm, auto-complete works differently. The:

  [ctrl] + [space]

keyboard shortcut still auto-suggests but doesn’t include non-imported classes, but the

  [ctrl] + [alt] + [space]

keyboard shortcut does! Displaying all available classes and auto-generating the import statement for you, just like in JetBrains other IDEs.