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Machine Coding

Machine Coding — Kanban

Learn to build an interactive Kanban Board in Angular using HTML5 Drag and Drop APIs, custom lists, column states, and status transitions.

Last Updated: July 15, 2026 • 13 min read

1. Learning Objectives

In this machine coding guide, you will build a dynamic, draggable Kanban Board. By the end of this exercise, you will be able to:

  • Handle HTML5 Drag and Drop API events (dragstart, dragover, drop) natively.
  • Manage column lanes and categorizations using signals.
  • Shift item records cleanly between states immutably.
  • Build adding input drawers to append cards to selected columns.
  • Apply drag indicators and CSS transitions to provide smooth feedback loops.

2. What We Are Building & Design System

Under interview settings, you are tasked with building a board organizer. Requirements include:

  • Columns View: Render columns (Todo, In Progress, Done). Each column contains stack cards.
  • Drag-and-Drop: Allow users to click and drag a card, dropping it into another column to change its status.
  • Adding Controls: Input fields inside columns to add new cards to that column quickly.
  • Deleting Cards: A delete action button on hover on cards to clear them from lists.

3. Step-by-Step Implementation Guide

Step 1: Declare Interfaces

Map tasks to statuses:

Step 2: Bind HTML5 Drag Handlers

Add draggable="true" to card elements. Listen to (dragstart) to save target item IDs:

Step 3: Handle Drop Actions

Listen to (dragover) and call event.preventDefault() to permit drops. Catch drops in (drop) to update states:

4. Full Working Code

Save this standalone component definition to build the Kanban Board:

5. Reviewing the Build / Self-Correction Checks

Verify your drag operations and list states update correctly:

  • Check drag start events: Verify that dragging a card copies its exact ID string payload to the transfer buffer.
  • Test status changes: Drag a card from "To Do" to "Done". Verify that the counts in the headers of both columns update immediately.

6. Practice Exercises & Extensions

Exercise 1: Implement card ordering indexes

Add an `order` property to cards. Integrate logic so that dropping a card inside a column sorts it into the exact slot index it was dropped (e.g. above or below existing cards).

7. Summary & Next Steps

By building this Kanban board, you have integrated drag-and-drop actions, mapped card statuses, and computed lane counters dynamically.

  • Next, proceed to **Machine Coding — Chat App** to build asynchronous message streams.
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