TILs - 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.

Published: Oct 9, 2024
Author: Nived Hari
System Analyst

"Search-as-You-Type" in Rails with Turbo Frames and Stimulus

Making the search box more interactive can be achieved with simple steps:

We could do this without Turbo by submitting the form whenever an input event occurs, right? No. In that case, on each input, the form gets submitted, and the input field loses focus. This is where Turbo Frames come into play. For this scenario, we need Turbo to reload only the content we want to update while leaving the rest of the page as it is.

For this, we define which part we want to reload based on our search by wrapping that particular section inside a turbo_frame_tag and targeting that Turbo Frame from the search form.

Sample search form:

Code

<%= form_with(
  url: search_path, method: :get,
  data: { turbo_frame: "frame_id", turbo_action: "advance", controller: "search", action: "input->search#submit" }
) do |f| %>
  <%= f.search_field field_name, placeholder: placeholder, value: params %>
<% end %>

turbo_frame : Points to the specific Turbo Frame we want to update with the search results. It allows us to reload only the content within this frame without affecting the rest of the page.
turbo_action : Defines the behavior of the Turbo request. In this case, it is set to "advance," which means the URL is appended to the previous ones. This allows users to navigate back to previous searches using the browser's back button, maintaining the search history. There are other actions like "restore", "pop" as well.

Example:

Code

<%= turbo_frame_tag "search_results" do %>
         #This will contain the search results
<% end %>

( We will give data : { turbo_frame: "search_results" } in this case )

In this way, when a fetch occurs from the search form, only the part inside the turbo_frame_tag is reloaded. The rest of the page remains untouched, and the form won't lose focus.

For optimization, we can add debouncing also, which can be done in the Stimulus controller.

#RubyOnRails #turbo #turbo_frames

Published: Oct 9, 2024
Author: Nitturu Baba
System Analyst

Fastest way to put website on internet:

Using Ngrok we can do that easily.

step1: install Ngrok

step2: create account in Ngrok website (for AUTHTOKEN)

step3: run the command in the terminal - ngrok authtoken YOUR_AUTHTOKEN

step4: add the regex in config/environment/development.rb

Code

Rails.application.configure do
    # Other configurations...
    
    # Add your Ngrok URL to the list of allowed hosts 
    config.hosts << /[a-z0-9\-]+\.ngrok-free\.app/
end

step5: start the server and open new terminal then in the project directory run the command ngrok http 3000 . Where 3000 is port number in which localhost is running.

step6: ngrok will give us a link, with that link we can access the website.

Ngrok is not only limited to rails. We can use with any framework.

#CU6U0R822 #ngrok

Published: Oct 8, 2024
Author: Nitturu Baba
System Analyst

How to Create a Multi-Language Website in Rails

Ruby on Rails comes with an integrated internationalization (I18n) framework that makes it simple to add multi-language support to your website.

Create Locale Files

You can define your translations using .yml files located in the config/locales directory.
For example, if your website supports English and Hindi, you would create two files: en.yml and hi.yml.

en.yml file:

Code

en:
    hello: "Hello"
    good_morning: "Good Morning %{name}"  # %{name} is used to pass dynamic parameters.
    rails: "Rails"

hi.yml file:

Code

hi:
    hello: "नमस्ते"
    good_morning: "शुभ प्रभात  %{name}"
    rails: "रेल"

Use Translations in Your Views

You can use the t helper method to access translations in your views.

Code

<%= t("hello") %>   // normal usage
<%= t("good_morning", name: t("rails")) %>  // Passing Dynamic Parameters.

Language Switching via URL

The language displayed will depend on the locale set in the URL. For example:
• If the URL is https://localhost:3000/en, the English translation will be used.
• If the URL is https://localhost:3000/hi, the Hindi translation will be used.
#CU6U0R822 #multi-language

Published: Oct 7, 2024
Author: Syed Sibtain
System Analyst

A Dead Letter Queue is a special queue in message queue systems that holds messages (payload) that cannot be delivered to their intended recipients due to various reasons.
These reasons can include:

• Incorrect message formatting
• Network errors
• System failures
• Application-level errors
DLQs serve several important purpose.

1. Message Preservation: They prevent loss of messages/payload that fail processing, allowing for later analysis or retry.
2. System Stability: By isolating problematic messages/payload, DLQs prevent failures from affecting the main message flow.
3. Debugging: DLQs provide a centralised location for developers to inspect and diagnose issues with failed messages.
#deadletterqueue #queuemanagement

Published: Oct 7, 2024
Author: Adithya Hebbar
System Analyst

https://Fly.io|Fly.io release_command

In https://Fly.io|Fly.io, the release_command is a special one-time command executed before deploying an app. It’s often used for tasks like running database migrations or other setup steps that need to happen before the app is fully launched. You can define it in your fly.toml file under the [deploy] section.

Example:

Code

[deploy]
  release_command = "python manage.py migrate"

This ensures your migrations or other essential pre-deploy tasks run seamlessly during the deployment process!

#fly #db_migrations

Published: Oct 7, 2024
Author: Ayasha Pandey
System Analyst

useFieldArray is a hook provided by React Hook Form that simplifies the process of managing dynamic form fields. It allows you to create forms where users can add, remove, move, and manipulate groups of inputs (or arrays of fields), like a list of tasks, addresses, or any repeatable form sections.
Features :-
1. Dynamic Fields Management
2. Efficient Rendering
Functions Provided by useFieldArray
• append(): Adds a new item to the end of the field array.
• prepend(): Adds a new item to the beginning of the field array.
• remove(index): Removes a field at the specified index.
• insert(index, value): Inserts a new field at a specific index.
#react-hook #react-form #form

Published: Oct 7, 2024
Author: Amber Srivastava

To create a model in Prisma:
1. Open the schema.prisma file.
2. Define datasource and generator:

Code

datasource db {
  provider = "postgresql"
  url      = env("DATABASE_URL")
}

generator client {
  provider = "prisma-client-js"
}

Create the model:

Code

model Retro {
  id              String   @id @default(cuid())
  date            DateTime @default(now())   // Auto-fills current date
  scrumMasterId   String                        // For Scrum Master (User)
  slackChannel    String                        // Slack Channel input
  questions       String[]                      // Default retro questions
  projectId       Int       @relation(fields: [projectId], references: [id])
  project         Project   @relation(fields: [projectId], references: [id])
}

This creates the Retro table for your retrospectives.

@id: Marks a field as the primary key.
@default(): Sets a default value for a field.
@relation(): Defines relationships between models.
@unique: Ensures a field has unique values.
String[]: Defines an array of strings.
cuid(): Generates a unique ID.
@updatedAt: Automatically updates the field with the current timestamp when data changes.

#prisma #database #columns #model

Published: Oct 7, 2024
Author: Aman Suhag
System Analyst

Mocking in Jest
Jest provides several ways to mock:
• jest.fn(): Creates a mock function that you can use instead of a real function.
• jest.mock(): Mocks entire modules.
• jest.spyOn(): Tracks calls to an existing method while optionally replacing its implementation.
#jest #test #mock

Published: Oct 2, 2024
Author: Ashwani Kumar Jha
Senior System Analyst

Async Local Storage in Node.js

• Provides us a way to store and manage context-specific data across asynchronous operations without needing to pass it explicitly through function arguments.
• Built on the async_hooks module, which tracks asynchronous resource lifecycle events.
• We need to use asyncLocalStorage.run(store, callback) to create a new context.
• Asynchronous operations initiated within this callback inherit that context.
• Each context created with asyncLocalStorage.run() is unique and does not interfere with other contexts.
• Common use cases can be maintaining custom context in our web app (e.g., request data, user ID...) across multiple layers (controllers, services, etc.), can help us with tracing how a request propagates through different async functions.
• Automatically cleans up the context after the asynchronous operations are complete.
• run(store, callback): Creates a new context and runs the callback with the provided store (like a Map or a primitive value).
• Set a value: asyncLocalStorage.getStore().set('requestId', requestId);
• Get a value: const requestId = asyncLocalStorage.getStore().get('requestId');

Code

const http = require('node:http');
const { AsyncLocalStorage } = require('node:async_hooks');
const { v4: uuid } = require('uuid');

const asyncLocalStorage = new AsyncLocalStorage();

function logWithId(msg) {
  const requestId = asyncLocalStorage.getStore(); 
  console.log(`${requestId} - ${msg}`);
}

function serviceA() {
  logWithId('Service A log');
}

function serviceB() {
  logWithId('Service B log');
}

http.createServer((req, res) => {
  const requestId = uuid();
  asyncLocalStorage.run(requestId, () => { 
    logWithId('Request received');
    serviceA();
    serviceB();
    logWithId('All services called');
    res.end('Response sent');
  });
}).listen(4040);

http.get('https://localhost:4040');

// Output:
<generated-request-id> - Request received
<generated-request-id> - Service A log
<generated-request-id> - Service B log
<generated-request-id> - All services called

Published: Sep 30, 2024
Author: Vaibhav Yadav
Senior System Analyst

## Avoid Mutating Objects Loaded from JSON Files

Today I learned that even if data is loaded from a static JSON file - once it's parsed and stored as a JavaScript object in memory, it behaves like any other object—meaning it's mutable by reference.

This means that modifying a property of an object loaded from a JSON file will mutate the original object in memory, affecting all references to that object across the app.

To avoid accidental mutations, it's best to create a copy of the object (using methods like { ...obj } for shallow copies) before modifying it. This ensures that the original data remains unchanged and helps prevent unexpected side effects throughout the codebase.

Example of creating a copy to avoid mutation:

Code

const content = { ...emails['Signup success'] };

This protects the original emails object from being modified, keeping the rest of the app safe from unintended changes.

---

It's a small but important detail when dealing with mutable JavaScript objects loaded from static sources!

#passByReference #js #json #objects

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