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Data Table

A complete, production-ready data table with sorting, filtering, pagination, row selection, and responsive design.

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Features Demonstrated

  • Two-way data binding - Search input, filters, page size

  • Computed properties - Filtered, sorted, and paginated data

  • repeat.for with keys - Efficient list rendering with tracking

  • Event handling - Sort, filter, pagination clicks

  • Conditional rendering - Empty states, loading states

  • Value converters - Date and number formatting

  • CSS class binding - Active sort, selected rows

  • Debouncing - Optimize search performance

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Code

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View Model (data-table.ts)

interface User {
  id: number;
  name: string;
  email: string;
  role: string;
  status: 'active' | 'inactive' | 'pending';
  lastLogin: Date;
  tasksCompleted: number;
}

type SortColumn = 'name' | 'email' | 'role' | 'status' | 'lastLogin' | 'tasksCompleted';
type SortDirection = 'asc' | 'desc';

export class DataTable {
  // Raw data (would normally come from API)
  private allUsers: User[] = [
    {
      id: 1,
      name: 'Alice Johnson',
      email: '[email protected]',
      role: 'Admin',
      status: 'active',
      lastLogin: new Date('2025-01-08'),
      tasksCompleted: 127
    },
    {
      id: 2,
      name: 'Bob Smith',
      email: '[email protected]',
      role: 'User',
      status: 'active',
      lastLogin: new Date('2025-01-09'),
      tasksCompleted: 89
    },
    {
      id: 3,
      name: 'Carol Williams',
      email: '[email protected]',
      role: 'Manager',
      status: 'inactive',
      lastLogin: new Date('2024-12-15'),
      tasksCompleted: 203
    },
    {
      id: 4,
      name: 'David Brown',
      email: '[email protected]',
      role: 'User',
      status: 'pending',
      lastLogin: new Date('2025-01-07'),
      tasksCompleted: 45
    },
    {
      id: 5,
      name: 'Eve Davis',
      email: '[email protected]',
      role: 'User',
      status: 'active',
      lastLogin: new Date('2025-01-09'),
      tasksCompleted: 156
    },
    // Add more sample data...
    {
      id: 6,
      name: 'Frank Miller',
      email: '[email protected]',
      role: 'Admin',
      status: 'active',
      lastLogin: new Date('2025-01-08'),
      tasksCompleted: 312
    },
    {
      id: 7,
      name: 'Grace Wilson',
      email: '[email protected]',
      role: 'Manager',
      status: 'active',
      lastLogin: new Date('2025-01-09'),
      tasksCompleted: 178
    },
    {
      id: 8,
      name: 'Henry Moore',
      email: '[email protected]',
      role: 'User',
      status: 'inactive',
      lastLogin: new Date('2024-11-20'),
      tasksCompleted: 67
    },
    {
      id: 9,
      name: 'Iris Taylor',
      email: '[email protected]',
      role: 'User',
      status: 'active',
      lastLogin: new Date('2025-01-09'),
      tasksCompleted: 234
    },
    {
      id: 10,
      name: 'Jack Anderson',
      email: '[email protected]',
      role: 'Manager',
      status: 'active',
      lastLogin: new Date('2025-01-08'),
      tasksCompleted: 189
    }
  ];

  // Filter state
  searchQuery = '';
  selectedRole: string = 'all';
  selectedStatus: string = 'all';

  // Sort state
  sortColumn: SortColumn = 'name';
  sortDirection: SortDirection = 'asc';

  // Pagination state
  currentPage = 1;
  pageSize = 5;

  // Selection state
  selectedRows = new Set<number>();

  // Loading state
  isLoading = false;

  // Computed: Filtered data
  get filteredUsers(): User[] {
    return this.allUsers.filter(user => {
      // Search filter
      const query = this.searchQuery.toLowerCase();
      const matchesSearch = !query ||
        user.name.toLowerCase().includes(query) ||
        user.email.toLowerCase().includes(query);

      // Role filter
      const matchesRole = this.selectedRole === 'all' ||
        user.role === this.selectedRole;

      // Status filter
      const matchesStatus = this.selectedStatus === 'all' ||
        user.status === this.selectedStatus;

      return matchesSearch && matchesRole && matchesStatus;
    });
  }

  // Computed: Sorted data
  get sortedUsers(): User[] {
    const sorted = [...this.filteredUsers];

    sorted.sort((a, b) => {
      let aVal: any = a[this.sortColumn];
      let bVal: any = b[this.sortColumn];

      // Handle dates
      if (aVal instanceof Date) {
        aVal = aVal.getTime();
        bVal = (bVal as Date).getTime();
      }

      // Handle strings (case-insensitive)
      if (typeof aVal === 'string') {
        aVal = aVal.toLowerCase();
        bVal = bVal.toLowerCase();
      }

      if (aVal < bVal) return this.sortDirection === 'asc' ? -1 : 1;
      if (aVal > bVal) return this.sortDirection === 'asc' ? 1 : -1;
      return 0;
    });

    return sorted;
  }

  // Computed: Paginated data
  get paginatedUsers(): User[] {
    const start = (this.currentPage - 1) * this.pageSize;
    const end = start + this.pageSize;
    return this.sortedUsers.slice(start, end);
  }

  // Computed: Pagination info
  get totalPages(): number {
    return Math.ceil(this.sortedUsers.length / this.pageSize);
  }

  get totalResults(): number {
    return this.sortedUsers.length;
  }

  get startResult(): number {
    if (this.totalResults === 0) return 0;
    return (this.currentPage - 1) * this.pageSize + 1;
  }

  get endResult(): number {
    return Math.min(this.currentPage * this.pageSize, this.totalResults);
  }

  pageSizeChanged(newValue: number | string) {
    const numeric = typeof newValue === 'string' ? Number(newValue) : newValue;
    if (typeof numeric === 'number' && !Number.isNaN(numeric) && numeric !== this.pageSize) {
      this.pageSize = numeric;
      return;
    }
    this.currentPage = 1;
  }

  get pages(): number[] {
    const pages: number[] = [];
    const maxVisible = 5;
    const half = Math.floor(maxVisible / 2);

    let start = Math.max(1, this.currentPage - half);
    let end = Math.min(this.totalPages, start + maxVisible - 1);

    // Adjust start if we're near the end
    if (end - start < maxVisible - 1) {
      start = Math.max(1, end - maxVisible + 1);
    }

    for (let i = start; i <= end; i++) {
      pages.push(i);
    }

    return pages;
  }

  // Computed: Selection state
  get allPageSelected(): boolean {
    if (this.paginatedUsers.length === 0) return false;
    return this.paginatedUsers.every(user => this.selectedRows.has(user.id));
  }

  get somePageSelected(): boolean {
    if (this.paginatedUsers.length === 0) return false;
    return this.paginatedUsers.some(user => this.selectedRows.has(user.id)) &&
      !this.allPageSelected;
  }

  // Actions
  sort(column: SortColumn) {
    if (this.sortColumn === column) {
      // Toggle direction
      this.sortDirection = this.sortDirection === 'asc' ? 'desc' : 'asc';
    } else {
      // New column, default to ascending
      this.sortColumn = column;
      this.sortDirection = 'asc';
    }
  }

  goToPage(page: number) {
    if (page < 1 || page > this.totalPages) return;
    this.currentPage = page;
  }

  nextPage() {
    this.goToPage(this.currentPage + 1);
  }

  previousPage() {
    this.goToPage(this.currentPage - 1);
  }

  toggleAllPageSelection() {
    if (this.allPageSelected) {
      // Deselect all on page
      this.paginatedUsers.forEach(user => this.selectedRows.delete(user.id));
    } else {
      // Select all on page
      this.paginatedUsers.forEach(user => this.selectedRows.add(user.id));
    }
  }

  clearSelection() {
    this.selectedRows.clear();
  }

  deleteSelected() {
    if (this.selectedRows.size === 0) return;

    const confirmed = confirm(`Delete ${this.selectedRows.size} user(s)?`);
    if (!confirmed) return;

    // Remove selected users
    this.allUsers = this.allUsers.filter(user => !this.selectedRows.has(user.id));

    // Clear selection
    this.selectedRows.clear();

    // Adjust page if needed
    if (this.currentPage > this.totalPages && this.totalPages > 0) {
      this.currentPage = this.totalPages;
    }
  }

  // Reset filters
  resetFilters() {
    this.searchQuery = '';
    this.selectedRole = 'all';
    this.selectedStatus = 'all';
    this.currentPage = 1;
  }

  // Watch for filter changes and reset to page 1
  searchQueryChanged() {
    this.currentPage = 1;
  }

  selectedRoleChanged() {
    this.currentPage = 1;
  }

  selectedStatusChanged() {
    this.currentPage = 1;
  }
}

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Template (data-table.html)

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Styles (data-table.css)

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How It Works

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Filtering Pipeline

Data flows through a pipeline:

  1. Raw data (allUsers) → all records

  2. Filtered (filteredUsers) → apply search and dropdown filters

  3. Sorted (sortedUsers) → apply column sorting

  4. Paginated (paginatedUsers) → slice for current page

Each computed property builds on the previous one, keeping the logic clean and testable.

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Sorting

Click column headers to sort. The first click sorts ascending, the second descending, and subsequent clicks toggle between the two. The active sort column is highlighted.

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Pagination

Smart pagination shows up to 5 page numbers with ellipsis for gaps. Always shows first and last pages. Automatically adjusts when filters reduce total pages.

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Selection

  • Checkbox in header selects/deselects all rows on current page

  • Individual row checkboxes for granular selection

  • Selected rows track across pages

  • Delete selected button removes all selected users

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Performance

  • Debounced search (300ms) prevents excessive filtering

  • Keyed repeat ensures efficient DOM updates

  • Computed properties cache results until dependencies change

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Variations

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Server-Side Pagination

For large datasets, move filtering/sorting to the server:

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Inline Editing

Add edit mode for quick updates:

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Column Visibility Toggle

Let users show/hide columns:

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Related

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