Stuff I'm Up To

Technical Ramblings

Application Construction — April 4, 2018

Application Construction

Frameworks

For rapid application development there’s a lot of pre-written code out there that is mature and highly capable. There’s no need to build from the ground up when you can use a framework or scaffolding to build your application.

Laravel and Composer

My first step is to use Laravel. It’s installed using composer – which is a dependency manager for PHP. This means if a PHP component you install needs and relies upon other components, they’ll get installed too.

Composer installs all the PHP dependencies under ./vendor path of your project. The files in this path do not need to be included in your distribution. They can be installed and updated automatically using composer.

Composer keeps track of what you install into your project in the file composer.json. So whenever you run $ composer update it will read this file and pull down all the dependencies and install them into ./vendor.

Node.js and NPM

Whilst I may not be developing a Node application I can certainly make use of Node for the development process. It offers some very beneficial development features. It runs webpack to monitor and compile the projects assets and browsersync to refresh my browser when an asset is updated.

NPM is the package management tool that downloads and installs the Node packages required. In the same way as composer installs dependencies for PHP, NPM does this for Node/JavaScript.

NPM uses the file package.json to monitor/manage the dependencies you install, which get installed into ./node_modules. Again this does not need to be included in your distribution as the content you require gets compiled into your JavaScript assets. So you may not even require Node installing on your production server environment.

Webpack

As part of the Laravel install you’ll get a flavour of Webpack, or mix as Laravel terms their adaption.

Webpack carries out the monitoring and compilation of assets. It takes your JavaScript and CSS/SASS files and uglifies/compresses them into smaller code only versions of your scripts. It can take a JavaScript file from 2MB of code down to less than 200kb. Simplistically it does this by stripping all of the “English” from it and shrinking your long variable and function names to what are often single character variable and function names. Removing spaces, tabs and carriage returns etc.

eg.

var my_variable_name = 1;

becomes

var a=1;

Once the code is delivered to the browser in a production environment there is no need for the code to be human readable anymore.

The primary input for webpack comes from the assets ./resources/assets/js/app.js and bootstrap.js (not to be confused with the bootstrap framework). These two files are the core of your JavaScript application.

Webpack compiles your assets into ./public/css/app.css and ./public/js/app.js. So you only have a few includes required in your projects HTML to use your assets. You can split them down further so 3rd party or vendor code is separated from your own code.

Vue.js

Laravel ships with Vue.js these days. This is very new to me and strangely different. It’s a JavaScript framework that is a totally different environment than my experience with jQuery. The main features that make it so different for me are the ability to bind data to components. This means a big change in the way you previously needed to monitor and trigger events based on changes in data. Vue.js does this for you.

Vue components live with your JavaScript assets under ./resources/assets/js/components. Once required/imported in your app.js file the .vue files get compiled into your application.

Bootstrap and Bootstrap-vue

Bootstrap is a HTML presentation framework. it provides the visual construction of the web page that the users of your application see. It’s the styling/CSS of the application. It’s a distinctive style, but very powerful in that designing for mobile, tablet through to desktop presentation is a built in function of the framework.

Bootstrap-vue is a Vue.js componentised implementation of Bootstrap. The need for writing HTML code in the manner of Bootstrap is taken over by writing vue components that build the Bootstrap HTML. So a Bootstrap button can become a vue component with data binding with actions and references like any other vue component. This brings program-ability to the visual presentation capabilities of Bootstrap.

Vuetify and Material Design

As an alternate presentation framework to Bootstrap/Bootstrap-vue on one project I’ve used Vuetify. Vuetify again is a very distinctive style. It uses the Google Material Design styles to present your application.

Application Delivery

After writing and testing the application locally I need to deploy it to a web server.

As part of my development process I use the Git version control system. This allows me to commit changes of my code in a controlled manner and enables me to rollback to previous versions, compare changes I’ve made and easily deploy the code to other systems.

For this I installed a Gitlab server so we have our own internal Git version control server. Using Github is only for publicly accessible code unless you take out a commercial package. Having our own Gitlab server provides the same functionality, but enables me to keep private projects internally.

To deploy the code to a server is as simple as compiling my assets for production and cloning the project to the server or pulling the changes.

Compile my production assets and upload/push them to the Gitlab server:

$ npm run prod
$ git add .
$ git commit -m "Production deployment"
$ git push

Then from the server clone the code and install/update the PHP dependencies:

$ git clone git@gitlab.domain.local/projectpath/project.git
$ composer update

or, to update the server:

$ git pull
$ composer update

Then it’s good to go.

So in all it seems a lot of components and when I started down this path I thought it all very confusing and more than a little daunting. But it’s like Lego. They all snap together quite tidily and the end result is a comprehensive application development and delivery platform.

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Vue.js, Laravel and JSON Web Tokens — March 28, 2018

Vue.js, Laravel and JSON Web Tokens

When you have a Vue.js powered app authentication using traditional logon pages isn’t going to work. This is because primarily the apps interaction with the server is using Ajax calls with axios. So now we need to use JSON Web Tokens (JWT) to handle the authentication and store a client side session authentication token.

This article is very useful for this: https://codeburst.io/api-authentication-in-laravel-vue-spa-using-jwt-auth-d8251b3632e0

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Access DFS Shares from Linux — March 27, 2018
Useful Vue.js components — March 22, 2018
Vue.js – Past the First Week — March 21, 2018

Vue.js – Past the First Week

I started recoding a project that I’d only just built using Vue.js as an exercise in learning Vue. The project had only just been deployed using Laravel 5.5, Bootstrap 3 and jQuery. So I rewrote it and used Laravel 5.5, Bootstrap 4 and Vue.js.

The initial project delivered a nav menu driven series of pages that presented tabular results with a search/filter capability, with some Ajax/XHR calls to update datatables.

I’d built several blade templates to deliver the content and used some excellent Open Source code for building PHP forms for the filters and result details – Kris’ laravel-form-builder. I used DataTables.net to present columns of data and it all came together quite well.

But then I switched to Vue.js and replaced the form builder and datatables with bootstrap-vue.

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Bootstrap-Vue — March 15, 2018
failed to mount component: template or render function not defined. —

failed to mount component: template or render function not defined.

Today I have been mostly smashing my head on the desk trying to figure out Laravel and Vue.js.

I thought I’d try to template an existing Laravel 5.5 project using Vue.js. Try as I might I could not get the template to work. I even stuck with the default example-component trying to get that to work . All I saw was an error reported in the console.

failed to mount component: template or render function not defined.

So I deployed a completely new Laravel project and added the example-component into the welcome page and it worked!

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Sweet Christmas – VS Code — March 13, 2018

Sweet Christmas – VS Code

Ok, so I know Microsoft have been making some big steps in the world of Open Source – I confess to giving them little ear time, mainly because EVERYTHING we seem to do at work ends up a licensing battle that Microsoft always win, and by win I mean empty this years budget in one go.

I’ve been using Atom as my editor of choice for some time now and really like it, but someone suggested I checkout Microsoft Visual Studio Code. I am aware of it. It has the same construction as atom – it’s based on Node.js and built using electron, just the same. So I installed it today… and wowsers! It’s impressive. It uses git and picks up the file changes using git status and I’d almost swear it was atom.

It even has extensions for linting! Of course it also has a PowerShell extension – which to be honest I found missing in atom when coding PS in Linux.

But I’m not 100% sold yet. Atom is going to take some beating. But I’m certainly more surprised by code than I thought I would be.

Code v1.2.1 at the time of writing.

PostGIS Import from PHP Session Fails — March 12, 2018

PostGIS Import from PHP Session Fails

When importing a CSV file using Laravel I found that I’d get some strange error messages relating to a called function not matching the parameters that I was sending.

local.ERROR: SQLSTATE[42883]: Undefined function: 7 ERROR: function st_makepoint(numeric, numeric) does not exist
LINE 1: SELECT ST_SetSRID(ST_MakePoint(NEW.x_coordinate, NEW.y_coord...
 ^
HINT: No function matches the given name and argument types. You might need to add explicit type casts.

I narrowed it down to the ST_SetSRID() and ST_MakePoint() functions and was 100% sure that they existed in the database, and with the right parameter types. I tried casting the values to double precision and still and the same errors.

The solution turned out to be that the function existed in the public schema NOT the schema I was using!

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Axios — February 28, 2018
Laravel 5 – jQuery File Upload — February 22, 2018

Laravel 5 – jQuery File Upload

I needed a mechanism to upload CSV files to my Laravel instance and then process them into a table. The first part was working out how I wanted to upload the files.

I came across blueimp-file-upload which seems pretty popular and capable.

There was no need to go overly fancy. Just a simple form will do as the file will probably be uploaded as a single file. First I had to figure out how to get blueimp into Laravel.

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MariaDB Apparmor and No login —

MariaDB Apparmor and No login

As I’ve been messing around with Sphinx I discovered that MariaDB actually includes the SphinxSE plugin out of the box. So I figured I’d ditch my MySQL installation on Debian and go back to the default Debian repository version MariaDB.

$ sudo apt-get remove mysql-server mysql-client

$ sudo apt-get install mariadb-server mariadb-client

This didn’t go to plan. Firstly it failed to run the apt configure scripts for mariadb-server-10.1 so it would not complete the install.

Checking the logs

Feb 21 15:52:29 mypc kernel: [ 323.603758] audit: type=1400 audit(1519228349.780:26): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/etc/mysql/mariadb.conf.d/" pid=5175 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=0 ouid=0

It goes back to a previous post I made about apparmor and MySQL. This time the problem was because the config file paths/names are different.

name="/etc/mysql/mariadb.conf.d/

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