Permutation Mail Merge is yet another example of recursion in PHP to achieve permutation (with order and without repetition).
Starting from the end, take a look at the output of the program to get an idea of what it does.
For a more detailed overview of Permutation Mail Merge, you can read the tutorial (also translated in Italian):
🇬🇧 Permutation with recursion in PHP
🇮🇹 Permutazione con ricorsione in PHP
The use case of this program is a customized version of Mail Merge, which is an operation that combine a text (which we'll call text_base)
with N contacts, inserting the contact in a position specified by a placeholder.
In our case, instead of having just 1 placeholder in the base_text, as in the classical Mail Merge,
we have N placeholders in the base_text.
The output is therfore a set of N! mails.
Each position is marked in the base_text by a placeholder.
With the current variables, the software finds all the possible combinations of a work teams of 5 contacts (so N=5) and produces the mails that describe each team.
The draft of the mail with a description of the work team is the base_text where each contact role position is marked by a placeholder.
The output is a set of 120 mails (5!=120 ... woah, some confusion between the mathematical notation "5 factorial equals 120", and the PHP comparison "5 differs from 120"; this is the first), that will be returned as an array assembled_texts.
The program is educational; it's written using the programming language PHP and the output is pure HTML.
All the words marked as code in this README are declared as variables in the program. If a word is plural (with a final "s") it's an indication that the variable is an array.
The source of the program is in the /src/index.php file.
You can see a static version of the output of the program (formatted as a valid HTML) on a GitHub Pages site.
A Docker Compose configuration (stack: "nginx" and "php-fpm") is included in the repository to allow you to execute the program without using your web server.
To execute the program with Docker Compose:
- Install and activate Docker (if you haven't already)
- Open the terminal
- Execute a
cdcommand in the main directory (the directory that contains the file docker-compose.yml). - Execute the command
docker-compose up - Open your browser and go to the address http://localhost
- Thanks to Hackmath website for the recap of the theoretical component of statistics.
- Thanks to Jesús Manuel Vargas for his docker-compose-php-stack that I have forked and rewrited.
- Thanks to W3C Validator for the validation of the HTML