Disclaimer :- Use this article content only for testing purposes . Do not use for real-time applications . Because there will be vulnerable incident can be occur via sites that not using the SSL Certificate.

In this post I’m going to show you how to develop an API . Actually this is an Insecure API because the two hosting providers I’m using doesn’t have the SSL certificate.

In the following table shows the things needed to be implemented ,

So my plan as in following diagram

So as the first task lets develop the code .

Here it is a PHP script acts as an API . The final output is valid JSON string

<?php

    header("Access-Control-Allow-Origin: *");
    header("Content-Type: application/json; charset=UTF-8");
    header("Access-Control-Allow-Methods: GET");
    header("Access-Control-Max-Age: 3600");
    header("Access-Control-Allow-Headers: Content-Type, Access-Control-Allow-Headers, Authorization, X-Requested-With");

    //open connection mysql
    $connection = mysqli_connect("host_address","mysql_username","mysql_password","mysql_database_name") or die("Error" .mysqli_error($connection));
    
    //fetch rows from mysql db
    $query = "SELECT  SUM(cases_count) AS total FROM dengu_cases_by_month";
    
    $data = "data";
    
    $result = mysqli_query($connection,$query) or die("Error in selecting data".mysqli_error($connection));
    
    //create an php array 
    $emp_array = array();
    while($row = mysqli_fetch_assoc($result)){
        $emp_array [$data] = $row; 
    }
    
    //return data as json
    echo json_encode($emp_array, JSON_PRETTY_PRINT);
?>

Actually above script returns the total dengue cases count in Sri Lanka.

After hosting this script in http://subdomain.000webhost.com we can get the output as the following json string ,

{
    "data": {
        "total": "31126"
    }
}

Actually the API is hosted as the following URL

http://subdomain.000webhost.com/api/dengu_case_api.php

Also we can get the Headers as in the following screenshot

Also we can check our API using curl command in “Windows” or “nix” based OS (Unix,Linux)

If we execute curl command via terminal to the API URL we can get the response as below screenshot

Then execute curl-I via terminal we can get the response headers as in below screenshot

So the first part is over

The second part is consume or use this API JSON string GET request via Ajax and display in the Dashboard .

Here I’m populate only the necessary HTML division and the JavaScript part . For the JavaScript part you can use modern angular , react library . For this test I’ve used JQuery JavaScript library .

The HTML div

<div class="container-fluid" style="border: solid 1px black; border-radius: 12px; max-width: 400px; padding: 0px">
    <h4 align="center"><b>Dengu Stats Sri Lanka</b></h4>
    <div class="col-sm-12" style="background-color:#33f3ff;">
        <div class="dengu_stats"></div>
    </div> 
    <br>
</div>

The JavaScript part

<script type="text/javascript">
    //get dengu stats
    $.getJSON('http://subdomain.000webhostapp.com/api/dengu_case_api.php', function(dengu_data) {
        
        var stats_dengu = `total count: ${dengu_data.data.total}<br>`
                    
        $(".dengu_stats").html(stats_dengu);
    });
</script>

After complete the above work we can see the final result as below

So how can we test this API for SSL enabled site ? . Let’s see how it works !

Here I have used “Heroku” as the hosting provider then created a dashboard to display the API already developed that outputs the count as a json string .

In this dashboard firstly the API data section not showing the values

After disabling the protection on the browser as below we can finally see the expected result ( disabling the protection on browser is not recommended ! )

After this step the browser automatically reloads ( Here in my case it is Firefox Browser ).

I think you will get an idea how to develop an API and how to consume it using another app after reading this article . This is a simple API . But you can develop more complex and advanced APIs to your data to day projects . Also this simple API data can be use for flutter mobile apps . Also can be used to develop extensions on web browsers like Google Chrome or Mozilla Firefox !

Have a nice day !

I think you have already installed and configured rust language in your computer according to my previous post Install Rust on your machine.

So first move to your preferred directory to create a project and issue the following command.

user@user-laptop:~$cargo new RustTtest

Here cargo will create the project folder within seconds .

Then move to the  project directory using  following command

user@user-laptop:~$ cd RustTest 

After that issue the following command to view the folder structure of the rust project.

user@user-laptop:~/ RustTest$ tree 

Then we can see the following structure in the terminal window ,

This is the simple basic structure of a rust project . Then let’s get a closer look at “Cargo.toml” . This is called a manifest or dependency descriptor file . It is like “package.json”   in npm project or “composer.json” in laravel project .

We can see the contents of “Cargo.toml” after issuing the following command .

user@user-laptop:~/ RustTest$ cat Cargo.toml 

So that file consists of the followings ,

Here we can see that there is separate section(s) for package description , dependencies description . Here we can modify package name,version number , author etc , also the dependencies which need to extend the capabilities of the project.

Then we look at the src folder contents using following command ,

user@user-laptop:~/ RustTest$ cat src/main.rs 

Here we can see code as below,

fn main() {
    println!("Hello, world!");
} 

Here   “fn main ()” describes the main function of the code and function body is describes within  the curly brackets “{}”

“println!” command basically outputs string or variable data .

Then we must compile the project before run by issuing the following command

user@user-laptop:~/ RustTest$ cargo build

you can see the following compiler output in the terminal

After build the project if you look at the project directory we can see that there is newly created directories and files . The compiled project is at the “/target/debug” directory.

Here we can run the compiled binary file via issuing the “cargo run” command or directly run the project using following command .

user@user-laptop:~/RustTest$ ./target/debug/RustTest

Ok , this is how to create and compile your first rust project . Hope you’ll get the idea .

If you have any issue please comment here !

have a nice day ! .

Rust is a system programming language focused on safe concurrency. Rust is  originally designed in Mozilla Labs by Graydon Hoare . You already know about popular ” Servo Rendering Engine project” created at “Mozilla Labs ” that is capable of parallel tab processing . Inspired by that parallel processing mechanism modern ” Mozilla Firefox Quantum Browser Project ” was created that is faster than old “Gecko Rendering Engine” based Mozilla Firefox Browser.

That is enough about that . So let’s get to know how to setup your personal computer for  “Rust Language” . Here I’ll show you configure it on your ubuntu linux machine. The Ubuntu version that I have used here is “18.04 LTS”. and the rust version is 1.45.0 . You’ll need curl as prerequisite for the installation . If there is no curl you can install it via curl as below.

sudo apt install curl 

Then to install rust issue the following commands

curl https://sh.rustup.rs -sSf | sh

According to official documentation  following command also work like a charm

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

After issuing the one of two above commands the following screen will be appeared

Here we have three options 1,2, and 3 .

1) Proceed with installation (default)

2) Customize installation

3) Cancel installation

It is better to choose 1st option to continue to the default installation  ( This will install the basic development tools ) . I’ll describe about the 2nd option in the next post .

After the there are two directories created in the “/home/user/” directory named “~/.rustup” and “~/.cargo” .

Here the rust language versioning and tool updates managed by rustup tool and above first directory for that purpose . The all Dev-tools are installed in the  “~/.cargo/bin”  directory.

After the installation issue the following command(s) in the terminal

rustup --version 
rustup 1.22.1 (b01adbbc3 2020-07-08) 

rustc --version 
rustc 1.45.0 (5c1f21c3b 2020-07-13)

cargo --version
cargo 1.45.0 (744bd1fbb 2020-06-15)

Here rustup is the version management tool that manages the rust versions (ex :- nightly builds,stable version etc).

Here cargo is the package manager for rust and crate host .

Ok that is the basic development installation for rust .

Bus that is not enough . We have to define “RUSTUP_HOME” and “CARGO_HOME” environmental variables . For that issue the following command in the terminal

sudo vim ~/.bashrc

Then add the lines as below ( this step must be do carefully )

export RUSTUP_HOME=/home/user/.rustup
export CARGO_HOME=/home/user/.cargo
export PATH=$PATH:$CARGO_HOME/bin 

After that  issue the following command(s) to make the changes permanent !

source ~/.bashrc

source ~/.profile 

Then issue the following command(s)  to ensure that all the settings are Ok .

echo $RUSTUP_HOME
/home/user/.rustup

echo $CARGO_HOME
/home/user/.cargo 

This is the basic steps of installation and  configuration of the rust language .

Have a nice day and leave a comment if you face an issue while installation of rust  language :- ) .

Here is a picture of my new toy and it is Nodemcu version 3.0 by third party Chinese manufacturer LoLin and its I/O expander board.

Note that this development board is only new to me and not new for the diy hobbyists all over the world .

This microcontroller manufactured by chinese company called “espressif” and they manufactured many variants of this “esp” chip for many wireless communication applications.

This board has some GPIO (General Purpose Input Output) features like other microcontrollers and specially the builtin WiFi facility (There is no builtin Wifi on Atmel AVR and PIC microcontrollers , we have to add it externally as a module) .

I’ll show you in future how to play with this gadget   and for today I think this is enough !

Have a nice day !

Ok , lets start …

before this your development environment must have the following requirements,

• php version >=5.6.4 , php 7 is good .
• Composer dependency manager
• Apache (httpd) server 2.4.
• Mysql database server >= 5.6 .

In this example I’ve used wamp server 2.5 on windows and updated the php version to 7.0.23 on wamp.

first you must open a command prompt on windows and move to “wamp\www” folder and issue the following command ,

c:\wamp\www\ composer create-project –prefer-dist cakephp/app test_cake3

then you must wait for 2 to 4 minutes to install the cakephp project on your computer.

After that move to the newly created project folder typing the following command

c:\wamp\www\ cd test_cake3

Then  you must issue the following command to run the project

c:\wamp\www\test_cake3\php -S localhost:8000 -t webroot

Here the “webroot” is your assets directory

So you can get the below as the welcome screen ..

Ok , that rocks , But it shows an alert in red as show in below screenshot ..

So , How to resolve this ?

Here we have to do two things,

1. Make the “my_app” database and,
2. Edit the “config/app.php” file parameters.

Ok , lets do it .

First open the mysql cli and issue the following command on it.

After that edit the “config/app,php” file. Scroll down the code until you find “Datasources” settings.

The default configurations of “config/app,php” file as below,

Apply the database name, username and password settings according to your mysql server settings. Here I have applied my computer’s mysql server parameters as below screenshot.

After that save the settings and refresh your cakephp welcome page . Here you can see that red  icon goes green .

So this is the method of fresh installing cakephp version 3.x project , here in my case “3.5.2 red velvet” on windows environment  : -).

Have a nice day … !

Both DS1307 and MPU6050 hold the hexadecimal address 0x68 . So the RaspberryPi’s I2C bus is confused when detecting the two devices. Then I’ve searched for the options . The DS1307 address can’t  be changed , it’s fixed one . So I have to choose the second option. Ground the AD0 pin of MPU6050 with VCC pin . So I soldered a little wire connecting both AD0 and VCC pins together shown as in below figure.

So after doing this simple diy hack the MPU6050’s device address should be 0x69. OK , let’s test the addresses that connected to the I2C bus of the RaspberryPi using the following command.

$ i2cdetect -r 2

So this is the result I’ve got

Aha that diy hack worked well!.

That s it

Now I’m ready to continue the experiment .

Important :- In this experiment I’ve used MPU6050 as a test device and it has AD0 pin. Here I’ve change the pin logic to 0 to 1 and that changed the  device address 0x68 to 0x69. Also keep in mind that this is a one method. Some I2C devices has software based address changing methods . In that type of devices we must read the manual and use a special firmware to change the I2C device address. We can use Arduino like microcontroller to run that special firmware to do that task.  

Have a nice day !

So I’ve decided to dig into that site. The site says it monitors many libraries across popular package managers.If you have github,gitlab or bitbucket you’ll be able to sign in to libraries.io with that any account credentials. It is a benefit without creating any new account or email.

After sign in you’ll be able to view and monitor you github or bitbucket repositories with that site . It is easy when you want to monitor your  all repositories in one location . Also this site shows the sources updates of libraries that are used in your own repository .

whoa , it is cool feature that I’ve seen on this site. That is called repository monitoring. This feature is free and can be enabled according to the below screenshot

When there are new component updates for your repository libraries.io send you notification emails as in below screenshots.

Ok , thats about libraries.io . Go and experience it :-).

Have a nice day !

First you have to install gemfile for mysql . This can be install issuing the following command in the terminal window.

 gem install mysql2

After that you can see the following progress on the terminal window

Then issue the following command to create new rails app that includes mysql support

 rails new testr -d mysql

After few minutes that will create your new rails app.

Now move to the development directory issuing the following command on terminal window.

 E:\>cd testr

Then issue the following command in  the terminal to run the app

 E:\testr> rails server

Then open your web browser and  type the following url in the address bar

 http://localhost:3000

Oops.. ! . There is an error occurred  . What can we do to resolve that error ?.

Ok, lets examine the database.yml in your app directory (in my example testr) using “Sublime Text” editor.

It shows us that there is a predefined database “testr_development” and we haven’t a database in our mysql server.

So to get rid of this we open the mysql command line interface and must issue the following command in it

 mysql> create schema testr_development;

After that refresh the browser window and also see the terminal window. You can see that following  result shows mysql is correctly configured with you project.

Yay! Now you know how to make ROR app with the support of mysql database.

Thats all .

Have happy coding and have a nice day !

This post shows how to update the ruby version on heroku,

These are the prerequisites on your windows machine before begin the update process

1. Node.js
2. Ruby 2.2.4
3. Heroku toolbelt
4. Git 1.8.6 >

That’s it.

Then you have to login to heroku account using this command

$ heroku login

Then you have to clone the site folder using git.

After that you have to move to the cloned site folder

If you want to update the bundler version of your site issue the following command inside the folder

Then configure the heroku build packs if your heroku ruby project issuing following command

To lock the bundler version if you have encountered an error we must have to lock it to specific version issuing following command in the terminal

After that open the gem file using your favorite text editor “notepad++” or “sublime text”

Then you have to add the following line to your ruby gem file inside your cloned folder.

You must add this line after the “source ‘https: //rubygems.org’ ” line

ruby “2.2.4”

https://devcenter.heroku.com/articles/ruby-versions

Then save the gem file, that’s all

There is no need to change the other lines of this file

Then issue the following commands one by one to push the source repository to the heroku.

That’s all after that you’ll see following successful progress screen

This is the final result after updating the ruby version “2.0.0” to “2.2.4”

Thats all . Have a nice day !

Let’s rock on!

Here firstly I’ve fully removed ruby 1.8.7 and ROR 4 from my machine. After that I’ve installed ruby 2.2.4 and ROR 5.0.0.1

After that in the terminal I’ve issued the following command

>rails new first_app

So it creates a new rails app

Oh looo..ong Screenshot

After that move to that newly created rails app folder and issue the following command in the windows or linux terminal.

first_app>rails server

After that type the following url in your web browser

http://localhost:3000/

Now you can see the browser screen as below.

Yay it rocks !

The main difference is the welcome page is been changed and it’s clean and simple .Also the web server moved to “WEBRICK” to “PUMA”.

Thats it !