Fueling Curiosity, One Insight at a Time

At Codemancers, we believe every day is an opportunity to grow. This section is where our team shares bite-sized discoveries, technical breakthroughs and fascinating nuggets of wisdom we've stumbled upon in our work.

Sep 12, 2024
To make your Django application ASGI-compatible and run it with Daphne, follow these steps:

1. Install Daphne: Install Daphne if you haven't already:



   pip install daphne


2. Ensure ASGI Configuration: Your asgi.py file should look like this:



   import os
   from django.core.asgi import get_asgi_application

   os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'your_project_name.settings')

   application = get_asgi_application()


3. Update settings.py: Add the ASGI_APPLICATION setting to point to your ASGI application:



ASGI_APPLICATION = 'your_project_name.asgi.application'


Replace 'your_project_name.settings' with the path to your Django settings module.

4. Run Daphne: Start Daphne with your ASGI application using:



   daphne -u your_project_name.asgi:application


Alternatively, run it on a specific port:



   daphne -p 8000 your_project_name.asgi:application


This setup will get your Django application running with Daphne as the ASGI server.

#python #django #daphne
adithya.hebbar
Adithya Hebbar
System Analyst
Sep 12, 2024
A Lambda layer in AWS Lambda is a feature that lets us manage and share common code and libraries across multiple Lambda functions. By creating a Lambda layer, we can package common code in its own module, which can then be used by our Lambda functions. This reduces duplication and simplifies the management of shared code.
ashwanikumarjha
Ashwani Kumar Jha
Senior System Analyst
Sep 10, 2024
We can generate a base64-encoded random key easily using either openssl or a combination of dd and base64. Here's how:



openssl rand -base64 32


Alternatively, using dd and base64:



dd if=/dev/urandom bs=32 count=1 2>/dev/null | base64


Both commands will give you a 32-byte random key encoded in base64.

#encryption #openssl
adithya.hebbar
Adithya Hebbar
System Analyst
Aug 28, 2024
To rename a table in TypeORM, follow these steps:

Create a new migration.


npx typeorm migration:create -n RenameTable


This will create a new migration file in the migrations directory

Edit the Migration File:


import { MigrationInterface, QueryRunner } from "typeorm";

export class RenameTable1724826351040 implements MigrationInterface {

    public async up(queryRunner: QueryRunner): Promise<void> {
        await queryRunner.renameTable('old_table_name', 'new_table_name');

    }

    public async down(queryRunner: QueryRunner): Promise<void> {
        await queryRunner.renameTable('new_table_name', 'old_table_name');
    }

}


Run the migration:


npm run typeorm -- migration:run


#typeorm #js
adithya.hebbar
Adithya Hebbar
System Analyst
Aug 27, 2024
Handling Image Uploads with Active Storage in Rails

Active Storage simplifies file uploads in Rails by attaching files to models.

Setup: Install Active Storage and run rails active_storage:install and rails db:migrate to create necessary tables.

Model Configuration: Use has_many_attached :images to allow multiple image uploads in our model. Example:


class SomeModel < ApplicationRecord
  has_many_attached :images
end


Form: Ensure the form includes multipart: true and allows multiple file uploads with form.file_field :images, multiple: true.

Controller: Permit images in the strong parameters with images: []. Example:


def some_params
  params.require(:some_model).permit(:note, images: [])
end


Migration: Remove old image columns if switching from direct storage to Active Storage.
#CU6U0R822 #activestorage #fileupload
syedsibtain
Syed Sibtain
System Analyst
Aug 27, 2024
To logout from Keycloak using the signOut function in NextAuth, you need to override the default behavior to ensure that the user is properly logged out from Keycloak as well. Here's how you can update your signOut function:


async signOut({ token }) {
  if (token.provider === "keycloak") {
    const issuerUrl = authOptions.providers.find((p) => p.id === "keycloak")
      .options!.issuer!;
    const logOutUrl = new URL(
      `${issuerUrl}/protocol/openid-connect/logout`
    );
    logOutUrl.searchParams.set("id_token_hint", token.id_token!);
    await fetch(logOutUrl);
  }
}


#keycloak #nextauth #nextjs #js
adithya.hebbar
Adithya Hebbar
System Analyst
Aug 8, 2024
Delegating Permissions in Pundit:

I encountered a scenario where I needed to retrieve the scope of one policy and use it within another policy. Specifically, I wanted to delegate permissions from one policy to another.

To address this issue, I learned to use Pundit's methods for manually retrieving policies and scopes:
Retrieving a Policy


Pundit.policy(user, record)  # Returns nil if the policy does not exist
Pundit.policy!(user, record) # Raises an exception if the policy does not exist


Retrieving a Policy Scope:


Pundit.policy_scope(user, ModelClass)  # Returns nil if the policy scope does not exist
Pundit.policy_scope!(user, ModelClass) # Raises an exception if the policy scope does not exist


These methods allowed me to delegate permissions effectively by retrieving and applying the appropriate scopes and policies

#rails #pundit #pundit-policy #authorization
giritharan
Giritharan
System Analyst
Aug 7, 2024
Quick Tip: How can we open a PR from one repository to another repository

1. Create the branch in the current repo


git checkout -b new-branch


2. Add the destination repository as a remote.


git remote add destination https://github.com/username/destination-repo.git


3. Push the new branch to the destination repository


git push destination new-branch


4. To check all the remote repositories added, we can do:


 git remote -v


Then, we create a PR in the destination repository from the new branch. This process effectively copies the changes from the original PR into a new PR in a different repository.

#github #git
syedsibtain
Syed Sibtain
System Analyst
Aug 6, 2024
Rails templates accept any locals as arguments. However, starting from Rails 7.1, we can restrict which locals a template must accept using "Strict Locals".



// _search.html.erb

<# locals: (:url, :field_name, :placeholder) -%>


We can also set default values


<# locals: (placeholder: "Search", :url, :field_name) -%>


#rails
sujay
sujay
Aug 3, 2024
Detecting a mobile browser using regex.

You can use regex which returns a true or false value depending on whether or not the user is browsing with a mobile. WOW!


window.mobilecheck = function () {
  var mobileCheck = false;
  (function (a) {
    if (
      /(android|bb\d+|meego).+mobile|avantgo|bada\/|blackberry|blazer|compal|elaine|fennec|hiptop|iemobile|ip(hone|od)|iris|kindle|lge |maemo|midp|mmp|mobile.+firefox|netfront|opera m(ob|in)i|palm( os)?|phone|p(ixi|re)\/|plucker|pocket|psp|series(4|6)0|symbian|treo|up\.(browser|link)|vodafone|wap|windows ce|xda|xiino/i.test(
        a
      ) ||
      /1207|6310|6590|3gso|4thp|50[1-6]i|770s|802s|a wa|abac|ac(er|oo|s\-)|ai(ko|rn)|al(av|ca|co)|amoi|an(ex|ny|yw)|aptu|ar(ch|go)|as(te|us)|attw|au(di|\-m|r |s )|avan|be(ck|ll|nq)|bi(lb|rd)|bl(ac|az)|br(e|v)w|bumb|bw\-(n|u)|c55\/|capi|ccwa|cdm\-|cell|chtm|cldc|cmd\-|co(mp|nd)|craw|da(it|ll|ng)|dbte|dc\-s|devi|dica|dmob|do(c|p)o|ds(12|\-d)|el(49|ai)|em(l2|ul)|er(ic|k0)|esl8|ez([4-7]0|os|wa|ze)|fetc|fly(\-|_)|g1 u|g560|gene|gf\-5|g\-mo|go(\.w|od)|gr(ad|un)|haie|hcit|hd\-(m|p|t)|hei\-|hi(pt|ta)|hp( i|ip)|hs\-c|ht(c(\-| |_|a|g|p|s|t)|tp)|hu(aw|tc)|i\-(20|go|ma)|i230|iac( |\-|\/)|ibro|idea|ig01|ikom|im1k|inno|ipaq|iris|ja(t|v)a|jbro|jemu|jigs|kddi|keji|kgt( |\/)|klon|kpt |kwc\-|kyo(c|k)|le(no|xi)|lg( g|\/(k|l|u)|50|54|\-[a-w])|libw|lynx|m1\-w|m3ga|m50\/|ma(te|ui|xo)|mc(01|21|ca)|m\-cr|me(rc|ri)|mi(o8|oa|ts)|mmef|mo(01|02|bi|de|do|t(\-| |o|v)|zz)|mt(50|p1|v )|mwbp|mywa|n10[0-2]|n20[2-3]|n30(0|2)|n50(0|2|5)|n7(0(0|1)|10)|ne((c|m)\-|on|tf|wf|wg|wt)|nok(6|i)|nzph|o2im|op(ti|wv)|oran|owg1|p800|pan(a|d|t)|pdxg|pg(13|\-([1-8]|c))|phil|pire|pl(ay|uc)|pn\-2|po(ck|rt|se)|prox|psio|pt\-g|qa\-a|qc(07|12|21|32|60|\-[2-7]|i\-)|qtek|r380|r600|raks|rim9|ro(ve|zo)|s55\/|sa(ge|ma|mm|ms|ny|va)|sc(01|h\-|oo|p\-)|sdk\/|se(c(\-|0|1)|47|mc|nd|ri)|sgh\-|shar|sie(\-|m)|sk\-0|sl(45|id)|sm(al|ar|b3|it|t5)|so(ft|ny)|sp(01|h\-|v\-|v )|sy(01|mb)|t2(18|50)|t6(00|10|18)|ta(gt|lk)|tcl\-|tdg\-|tel(i|m)|tim\-|t\-mo|to(pl|sh)|ts(70|m\-|m3|m5)|tx\-9|up(\.b|g1|si)|utst|v400|v750|veri|vi(rg|te)|vk(40|5[0-3]|\-v)|vm40|voda|vulc|vx(52|53|60|61|70|80|81|83|85|98)|w3c(\-| )|webc|whit|wi(g |nc|nw)|wmlb|wonu|x700|yas\-|your|zeto|zte\-/i.test(
        a.substr(0, 4)
      )
    )
      mobileCheck = true;
  })(navigator.userAgent || navigator.vendor || window.opera);
  return mobileCheck;
};


I wonder who in the world wrote this snippet!!! :)

#javascript #browser
adithya.hebbar
Adithya Hebbar
System Analyst

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