TILs - Fueling Curiosity, One Insight at a Time

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Published
Author
user-image
Syed Sibtain
System Analyst
In Ruby, attr_reader and attr_accessor are used to create getter and setter methods for class attributes. These are part of a group of methods (attr_* methods) that make it easier to create getter and setter methods for class attributes.

attr_reader: Creates a getter method, allowing read-only access to an instance variable.

Code

class Person
  attr_reader :name

  def initialize(name)
    @name = name
  end
end

person = Person.new("Sibtain")
puts person.name  # Outputs: Sibtain


attr_accessor: Creates both getter and setter methods, allowing read and write access to an instance variable.

Code

class Person
  attr_accessor :name

  def initialize(name)
    @name = name
  end
end

person = Person.new("Sibtain")
puts person.name  # Outputs: Sibtain

person.name = "John"
puts person.name  # Outputs: John


Furthermore, using attr_reader and attr_accessor promotes encapsulation by controlling how the attributes of a class are accessed and modified.

#ruby #rubyonrails
Published
Author
user-image
Amber Srivastava
------------------------- useFieldArray hook in react-hook-form -------------------------
The useFieldArray hook is part of react-hook-form and is used for handling dynamic fields in forms, such as arrays of inputs that can be added or removed dynamically.
For example, if you have a list of items (like questions, tasks, or other fields) that can be added, removed, or reordered during form submission, useFieldArray is the ideal solution to manage that dynamic behaviour without manually managing the state of each individual field.

How useFieldArray works:
• fields: An array of objects, where each object represents a field in the array.
• append: A function to add new fields to the array.
• remove: A function to remove fields from the array.
• update: A function to update an individual field in the array.
Example:-

Code

import { useForm, useFieldArray } from "react-hook-form";

function DynamicForm() {
  const { register, control, handleSubmit, formState: { errors } } = useForm({
    defaultValues: {
      questions: [{ question: "" }],
    },
  });

  // UseFieldArray to handle the questions array dynamically
  const { fields, append, remove } = useFieldArray({
    control,
    name: "questions",  // Name of the array in the form's state
  });

  const onSubmit = (data: any) => {
    console.log(data); // Submitting form data with dynamic fields
  };

  return (
    <form onSubmit={handleSubmit(onSubmit)}>
      {fields.map((item, index) => (
        <div key={item.id}>
          <input
            {...register(`questions.${index}.question`)}  // Register each question dynamically
            defaultValue={item.question}  // Set default value for each item in the array
          />
          {errors.questions?.[index]?.question && (
            <span>{errors.questions[index]?.question.message}</span>
          )}
          <button type="button" onClick={() => remove(index)}>Remove</button>
        </div>
      ))}
      
      <button type="button" onClick={() => append({ question: "" })}>
        Add Question
      </button>

      <button type="submit">Submit</button>
    </form>
  );
}


Key Points:
1. name: The name prop in useFieldArray points to the field array in your form state (in this case, questions).
2. fields: This array holds the current data of the dynamic fields. Each item corresponds to a field in the form array.
3. append: This method is used to add a new item to the array. You can pass the new data for the item when appending.
4. remove: This method is used to remove an item by its index.
When to use useFieldArray:
• Dynamic Forms: When you have a form where the number of fields can change over time, such as adding/removing questions, tasks, team members, etc.
• Nested Fields: When you have an array of objects (e.g., an array of questions, where each question has a title and description).
Advantages:
• It reduces the need for manual state management when adding/removing fields.
• It integrates seamlessly with react-hook-form to handle validations and form submission.
• It improves performance by avoiding unnecessary re-renders when fields are added or removed.
#CCT1JMA0Z #useForm #react-hook-form
Published
Author
user-image
Ayasha Pandey
System Analyst
Slack's chat.deleteScheduledMessage API allows you to delete messages that were scheduled using chat.scheduleMessage but have not yet been sent.

Code

const response = await slackClient.chat.deleteScheduledMessage({
  channel: channelId, {// ID of the channel where the message was scheduled }
  scheduled_message_id: scheduledMessageId, {// ID of the scheduled message to delete}
});


#slack #api
Published
Author
user-image
Nitturu Baba
System Analyst
How to write tests for external APIs?

This can be achieved using the gem "webmock".

Using webmock we will similate the external API call and use mockdata as the response to the APIs.

step1: install the gem "webmock"
step2: add the following lines to rails helper.

Code

require 'webmock/webmock_api.rb'

config.before(:each) do
    stub_request(:any, /domain_name/).to_rack(WebmockApi
end


step3: create mock data responses for the APIs inside fixtures folder in spec.

member_api_success.json

Code

# spec/fixtures/member_api_success.json
[
  {
    "id": 1,
    "name": "John Doe",
    "email": "john.doe@example.com",
    "phone": "123-456-7890",
    "membership_type": "Gold",
    "status": "active"
  },
  {
    "id": 2,
    "name": "Jane Smith",
    "email": "jane.smith@example.com",
    "phone": "987-654-3210",
    "membership_type": "Silver",
    "status": "inactive"
  }
]


step4: inside spec create webmock file. Inside webmock create webmock_api.rb file. In this file we will simulate the responses for the API using mock data we have created.

Code

class WebmockApi
  SPEC_FIXTURES_PATH = 'spec/fixtures'.freeze
  MEMBERS_SUCCESS = File.read("#{SPEC_FIXTURES_PATH}/members_api_success.json").freeze
  POSTS_SUCCESS = File.read("#{SPEC_FIXTURES_PATH}/posts_api_success.json").freeze
  ERROR = File.read("#{SPEC_FIXTURES_PATH}/error.json").freeze

  def self.call(env)
    new.call(env)
  end

  def call(env)
    action = env['REQUEST_METHOD']
    path = env['PATH_INFO']
    params = env['QUERY_STRING']

    case path
    when '/external_members_api_path'
      params.include?('test_user') ? [ 200, {}, [ MEMBERS_SUCCESS ] ] : [ 500, {}, [ ERROR ] ]
    when '/external_post_api_path'
      params.include?('new_post') ? [ 200, {}, [ POSTS_SUCCESS ] ] : [ 500, {}, [ ERROR ] ]
    end
  end
end


step5: write the test cases for the APIs in requests folder.

Code

require 'rails_helper'
require 'webmock/rspec'

RSpec.describe "Members", type: :request do
  describe "GET /members_search_path" do
    context "when the members API call is successful" do
      it "returns member details from the API" do
        get "/external_members_api_path", params: { member: "test_user" }

        expect(response).to have_http_status(:ok)
        user = response.parsed_body["member"]
        expect(["id"]).to eq("123456")
        expect(user["name"]).to eq("abc")
      end
    end
    
    context "when the members API call is successful" do
      it "returns error message from the API" do
        get "/external_members_api_path", params: { member: "unknown_user" }

        expect(response).to have_http_status(:ok)
        expect(response).to have_http_status(:internal_server_error)
        error = response.parsed_body["error"]
        expect(error).to eq("Something went wrong")
      end
    end
  end
end


#ruby on rails
Published
Author
user-image
Amber Srivastava
SEND SLACK MESSAGE AS A THREAD

To send a message as a thread in Slack using the Slack API, we can use the chat.postMessage method with the thread_ts parameter. This parameter specifies the timestamp (ts) of the parent message you want to reply to, creating a thread.

Here’s how to send a threaded message:
1. Get the ts (timestamp) of the Parent Message
• If you’re replying to a specific message, you’ll need its ts value. You can retrieve it by fetching messages in the channel, or from the response of a previously sent message.
2. Send a Threaded Message Using thread_ts
• Use thread_ts in the chat.postMessage payload to post your message as a reply in the thread.
Example:-

Code

import { WebClient } from "@slack/web-api";

const client = new WebClient("YOUR_SLACK_BOT_TOKEN");

async function sendThreadedMessage(channel: string, parent_ts: string, message: string) {
  try {
    // Post a new message as a reply in the thread
    const response = await client.chat.postMessage({
      channel,
      text: message,
      thread_ts: parent_ts, // This makes it a threaded message
    });
  } catch (error) {
    console.error("Error sending threaded message:", error);
  }
}

// Usage example
sendThreadedMessage("C123456789", "1688852910.123456", "This is a reply in the thread.");


If we don't have any parent message then,we can first send a message and then use its ts as the thread_ts for replies:

Code

async function sendMessageWithThread(channel: string, message: string, replyMessage: string) {
  try {
    // Send the parent message
    const parentMessage = await client.chat.postMessage({
      channel,
      text: message,
    });

    // Reply to the message in a thread
    await client.chat.postMessage({
      channel,
      text: replyMessage,
      thread_ts: parentMessage.ts,
    });
  } catch (error) {
    console.error("Error sending messages:", error);
  }
}

// Usage example
sendMessageWithThread("C123456789", "This is the main message", "This is a reply in the thread.");


#C04A9DMK81E #slack #slackapi #thread
Published
Author
user-image
Satya
When working with Stimulus, it's common to dynamically update DOM elements. While string interpolation works, using HTML <template> elements is a cleaner and more maintainable approach.
#CU6U0R822 #stimulus #templates

String interpolation

Code

// In your stimulus controller 
updateList() {
  this.listTarget.innerHTML = `
    <div class="flex gap-2">
      <span>${this.name}</span>
      <button>Delete</button>
    </div>
  `
}


HTML Templates

Code

// In your view 
<template data-list-target="template">
  <div class="flex gap-2">
    <span data-placeholder="name"></span>
    <button>Delete</button>
  </div>
</template>

// In your Stimulus controller
updateList() {
  const template = this.templateTarget.content.cloneNode(true)
  template.querySelector('[data-placeholder="name"]').textContent = this.name
  this.listTarget.appendChild(template)
}

Published
Author
user-image
Syed Sibtain
System Analyst
In a Rails application, we can provide different views and behaviours based on the type of device accessing our application. One of the ways to achieve this is by using the set_variant method along with mobile-specific templates like index.html+mobile

1. First, determine if the request is coming from a mobile device and set variant in the controller.

Code

def set_variant
    browser = Browser.new(request.user_agent)

    if browser.device.mobile?
      request.variant = :mobile
    else
      request.variant = :desktop
    end
  end


2. Now, create mobile-specific views. For example, if we have an index.html.erb view, we can create a mobile-specific version by adding +mobile to the filename.

Code

app/views/orders/index.html.erb
app/views/orders/index.html+mobile.erb


With the variant set, Rails will automatically choose the correct view.

#rubyonrails
Published
Author
user-image
Ayasha Pandey
System Analyst
useFetch is a Nuxt composable used to fetch data in a server-side or client-side context, ensuring data is fetched before rendering the component. It is primarily used for making HTTP requests and providing a reactive way of managing the fetched data.

useAsyncData is very similar to useFetch, but it allows for fetching data asynchronously, without blocking the server-side rendering process. It's useful when you want to fetch data in a non-blocking way, enabling the page to render without waiting for the data.

Key Difference:
• useFetch fetches data synchronously during SSR, blocking the rendering process until the data is available.
• useAsyncData fetches data asynchronously, allowing the page to render without waiting for the data.
#fetch #nuxt #useFetch #useAsyncData
Published
Author
user-image
Nitturu Baba
System Analyst
In Rails, forms can be created in two ways: with a URL (using form_with url: ...) or with a model (using form_with model: ...).
But, when to use which?

Form with URL (form_with url: ...)
This form is used when you specify a URL directly and typically use it for non-resourceful actions or when you don’t have a specific model associated with the form.

Code

<%= form_with url: some_path, method: :post do |form| %>
  <%= form.text_field :some_field %>
  <%= form.submit "Submit" %>
<% end %>


The form_with_url is suitable for forms that don't map directly to a model, like search forms, login forms, or other custom actions etc.

Form with Model (form_with model: ...)
This form is bound to an instance of a model, allowing Rails to automatically set the form action (URL) and method (POST or PATCH) based on whether the model is a new record or an existing one.

Code

<%= form_with model: @record do |form| %>
  <%= form.text_field :name %>
  <%= form.submit %>
<% end %>


Rails determines the correct URL and HTTP method based on the record's state:
• New Record: If @record.new_record? is true, Rails generates a POST request to the model’s create route.
• Existing Record: If @record.persisted? is true, Rails generates a PATCH request to update the model’s update route.
The form_with_model is suitable for forms that directly interact with a model, such as forms for creating or editing a resource (like User, Post, etc.).

#ruby on rails
Published
Author
user-image
Adithya Hebbar
System Analyst
To update a user’s password in AWS Cognito and set it as permanent, we can use the AWS CLI with the following admin command:

Code

aws cognito-idp admin-set-user-password \
    --user-pool-id <pool-id> \
    --username <cognito-username> \
    --password <password> \
    --permanent


#auth #aws #cognito

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