This project is a simple web coding test as the second step for a job application. This app is developed with Lumen. it should draw geometric shapes such as circle, square, rectangle, ellipse... etc. Each shape might have various attributes like border color and size, fill color... etc.
It should support adding more shapes quickly, easily and with minimum code changes. It provides an implementation for the circle and the square shapes. The application also should display the result (i.e. the drawn shapes) in any format: array of points, image (binary file)... I call them drivers in the code.
1. $ clone [email protected]:eissasoubhi/GraphicEditor.git
2. $ cd GraphicEditor/
3. $ composer install
The first thing we run the server with php -S localhost:4000 -t public
The application exposes an endpoint that receives JSON input.
To see the result, you'll have to send a post request to this link http://localhost:4000/draw with json input in a post parameter with the name 'data'. The best way to do that is by using Postaman, a pefect app for api calls.
This is a JSON exmple to send with the post request:
{"shapes":[{"type":"circle","perimeter":500,"border":{"color":"#ff0000","width":6}},{"type":"square","sideLength":100,"border":{"color":[133,55,22],"width":10}},{"type":"square","sideLength":200,"border":{"color":"#776cff","width":5}},{"type":"circle","perimeter":800,"border":{"color":"green","width":4}}]}
This is a screenshot of Postman with the link:
The application checks the validation of the shapes types and their attributes. if they are invalid or misspelled it throws an exception. The color attribute of the shapes can be in three different forms, hex eg: #FF0000, array eg: [255, 0, 0] or the color name eg: red.
The application is decoupled to different parts:
Drivers: the implementation of the output for both binary and points types. each shape has its own drivers of both types
Format: outputs the result depending on the driver type, each driver type has its own corresponding format.
Shapes.
Shapes attributes.
GraphicEditor: orchestrate the above classes to produce the desired result
The core components are the drivers, so here is how they work:
The Binary driver: it simply uses the PHP GD library to draw the shapes.
The Points driver: this one is the catch, it should normally display the shape as an array of points (pixels), but the only way could find to do that is by making a binary image first then convert that image later to an array of pixels. It works well but the problem here is that the Points driver will be depending on the Binary driver in order to work, so what I did is I extracted the code that creates an image from the Binary driver classes into traits and imported those traits in both Binary and Points drivers classes.
As stated in the beginning, this app should support adding more shapes quickly, easily and with minimum code. Let's say you wanna add the line shape:
- The first thing to do is create a folder with name Line in
app/Drivers/Line with three files inside it: Binary.php, Points.php,
and BinaryDrawerTrait.php.
- In Binary.php and Points.php, mostly the only thing to change in them is the namespace.
- In BinaryDrawerTrait.php you define the draw function for the shape Line.
- The last thing is to add the shape app/Shapes/Line.php with the right functions definitions.
Optionally, you can add attributes too, let's say you wanna add the sideLenght that accept values in different units: px, cm.. the only thing you'll have to do is to add a class app/Shapes/Attributes/SideLenght.php and make sure it extends the class app/Shapes/Attributes/AttributeAbstract.php then the application will load it automatically when it detects it.