oqtane.framework/Oqtane.Client/Modules/Controls/Pager.razor

@namespace Oqtane.Modules.Controls
@inherits ModuleControlBase
@typeparam TableItem

@if (ItemList != null)
{
    @if ((Toolbar == "Top" || Toolbar == "Both") && _pages > 0 && Items.Count() > _maxItems)
    {
        <ul class="pagination justify-content-center my-2">
            <li class="page-item@((_page > 1) ? "" : " disabled")">
                <a class="page-link" @onclick=@(async () => UpdateList(1))><span class="oi oi-media-step-backward" title="start" aria-hidden="true"></span></a>
            </li>
            @if (_pages > _displayPages && _displayPages > 1)
            {
                <li class="page-item@((_page > _displayPages) ? "" : " disabled")">
                    <a class="page-link" @onclick=@(async () => SkipPages("back"))><span class="oi oi-media-skip-backward" title="skip back" aria-hidden="true"></span></a>
                </li>
            }
            <li class="page-item@((_page > 1) ? "" : " disabled")">
                <a class="page-link" @onclick=@(async () => NavigateToPage("previous"))><span class="oi oi-chevron-left" title="previous" aria-hidden="true"></span></a>
            </li>
            @for (int i = _startPage; i <= _endPage; i++)
            {
                var pager = i;
                if (pager == _page)
                {
                    <li class="page-item active">
                        <a class="page-link" @onclick=@(async () => UpdateList(pager))>@pager</a>
                    </li>
                }
                else
                {
                    <li class="page-item">
                        <a class="page-link" @onclick=@(async () => UpdateList(pager))>@pager</a>
                    </li>
                }
            }
            <li class="page-item@((_page < _pages) ? "" : " disabled")">
                <a class="page-link" @onclick=@(async () => NavigateToPage("next"))><span class="oi oi-chevron-right" title="next" aria-hidden="true"></span></a>
            </li>
            @if (_pages > _displayPages && _displayPages > 1)
            {
                <li class="page-item@((_endPage < _pages) ? "" : " disabled")">
                    <a class="page-link" @onclick=@(async () => SkipPages("forward"))><span class="oi oi-media-skip-forward" title="skip forward" aria-hidden="true"></span></a>
                </li>
            }
            <li class="page-item@((_page < _pages) ? "" : " disabled")">
                <a class="page-link" @onclick=@(async () => UpdateList(_pages))><span class="oi oi-media-step-forward" title="end" aria-hidden="true"></span></a>
            </li>
            <li class="page-item disabled">
                <a class="page-link" style="white-space: nowrap;">Page @_page of @_pages</a>
            </li>
        </ul>
    }
    @if (Format == "Table" && Row != null)
    {
        <table class="@Class">
            <thead>
                <tr>@Header</tr>
            </thead>
            <tbody>
                @foreach (var item in ItemList)
                {
                    <tr>@Row(item)</tr>
                    @if (Detail != null)
                    {
                        <tr>@Detail(item)</tr>
                    }
                }
            </tbody>
        </table>
    }
    @if (Format == "Grid" && Row != null)
    {
        int count = 0;
        if (ItemList != null)
        {
            count = (int)Math.Ceiling(ItemList.Count() / (decimal)_columns) * _columns;
        }
        <div class="@Class">
            @if (Header != null)
            {
                <div class="row"><div class="col">@Header</div></div>
            }
            @for (int row = 0; row < (count / _columns); row++)
            {
                <div class="row">
                    @for (int col = 0; col < _columns; col++)
                    {
                        int index = (row * _columns) + col;
                        if (index < ItemList.Count())
                        {
                            <div class="col">@Row(ItemList.ElementAt(index))</div>
                        }
                        else
                        {
                            <div class="col">&nbsp;</div>
                        }
                    }
                </div>
            }
        </div>
    }
    @if ((Toolbar == "Bottom"  || Toolbar == "Both") && _pages > 0 && Items.Count() > _maxItems)
    {
        <ul class="pagination justify-content-center my-2">
            <li class="page-item@((_page > 1) ? "" : " disabled")">
                <a class="page-link" @onclick=@(async () => UpdateList(1))><span class="oi oi-media-step-backward" title="start" aria-hidden="true"></span></a>
            </li>
            @if (_pages > _displayPages)
            {
                <li class="page-item@((_page > _displayPages) ? "" : " disabled")">
                    <a class="page-link" @onclick=@(async () => SkipPages("back"))><span class="oi oi-media-skip-backward" title="skip back" aria-hidden="true"></span></a>
                </li>
            }
            <li class="page-item@((_page > 1) ? "" : " disabled")">
                <a class="page-link" @onclick=@(async () => NavigateToPage("previous"))><span class="oi oi-chevron-left" title="previous" aria-hidden="true"></span></a>
            </li>
            @for (int i = _startPage; i <= _endPage; i++)
            {
                var pager = i;
                if (pager == _page)
                {
                    <li class="page-item active">
                        <a class="page-link" @onclick=@(async () => UpdateList(pager))>@pager</a>
                    </li>
                }
                else
                {
                    <li class="page-item">
                        <a class="page-link" @onclick=@(async () => UpdateList(pager))>@pager</a>
                    </li>
                }
            }
            <li class="page-item@((_page < _pages) ? "" : " disabled")">
                <a class="page-link" @onclick=@(async () => NavigateToPage("next"))><span class="oi oi-chevron-right" title="next" aria-hidden="true"></span></a>
            </li>
            @if (_pages > _displayPages)
            {
                <li class="page-item@((_endPage < _pages) ? "" : " disabled")">
                    <a class="page-link" @onclick=@(async () => SkipPages("forward"))><span class="oi oi-media-skip-forward" title="skip forward" aria-hidden="true"></span></a>
                </li>
            }
            <li class="page-item@((_page < _pages) ? "" : " disabled")">
                <a class="page-link" @onclick=@(async () => UpdateList(_pages))><span class="oi oi-media-step-forward" title="end" aria-hidden="true"></span></a>
            </li>
            <li class="page-item disabled">
                <a class="page-link">Page @_page of @_pages</a>
            </li>
        </ul>
    }
}

@code {
    private int _pages = 0;
    private int _page = 1;
    private int _maxItems = 10;
    private int _displayPages = 5;
    private int _startPage = 0;
    private int _endPage = 0;
    private int _columns = 1;

    [Parameter]
    public string Format { get; set; } // Table or Grid

    [Parameter]
    public string Toolbar { get; set; } // Top, Bottom or Both

    [Parameter]
    public RenderFragment Header { get; set; } = null;

    [Parameter]
    public RenderFragment<TableItem> Row { get; set; } = null;

    [Parameter]
    public RenderFragment<TableItem> Detail { get; set; } = null; // only applicable to Table layouts

    [Parameter]
    public IEnumerable<TableItem> Items { get; set; } // the IEnumerable data source

    [Parameter]
    public string PageSize { get; set; } // number of items to display on a page

    [Parameter]
    public string Columns { get; set; } // only applicable to Grid layouts

    [Parameter]
    public string CurrentPage { get; set; } // optional property to set the initial page to display

    [Parameter]
    public string DisplayPages { get; set; } // maximum number of page numbers to display for user selection

    [Parameter]
    public string Class { get; set; }

    private IEnumerable<TableItem> ItemList { get; set; }

    protected override void OnParametersSet()
    {
        if (string.IsNullOrEmpty(Format))
        {
            Format = "Table";
        }

        if (string.IsNullOrEmpty(Toolbar))
        {
            Toolbar = "Top";
        }

        if (string.IsNullOrEmpty(Class))
        {
            if (Format == "Table")
            {
                Class = "table table-borderless";
            }
            else
            {
                Class = "container-fluid px-0";
            }
        }

        if (!string.IsNullOrEmpty(PageSize))
        {
            _maxItems = int.Parse(PageSize);
        }

        if (!string.IsNullOrEmpty(Columns))
        {
            _columns = int.Parse(Columns);
        }

        if (!string.IsNullOrEmpty(DisplayPages))
        {
            _displayPages = int.Parse(DisplayPages);
        }

        if (!string.IsNullOrEmpty(CurrentPage))
        {
            _page = int.Parse(CurrentPage);
        }
        else
        {
            _page = 1;
        }

        _startPage = 0;
        _endPage = 0;

        if (Items != null)
        {
            _pages = (int)Math.Ceiling(Items.Count() / (decimal)_maxItems);
            if (_page > _pages)
            {
                _page = _pages;
            }
            ItemList = Items.Skip((_page - 1) * _maxItems).Take(_maxItems);
            SetPagerSize();
        }
    }

    public void SetPagerSize()
    {
        _startPage = ((_page - 1) / _displayPages) * _displayPages + 1;
        _endPage = _startPage + _displayPages - 1;
        if (_endPage > _pages)
        {
            _endPage = _pages;
        }
        StateHasChanged();
    }

    public void UpdateList(int page)
    {
        ItemList = Items.Skip((page - 1) * _maxItems).Take(_maxItems);
        _page = page;
        SetPagerSize();
    }

    public void SkipPages(string direction)
    {
        switch (direction)
        {
            case "forward":
                _page = _endPage + 1;
                break;
            case "back":
                _page = _startPage - 1;
                break;
        }

        SetPagerSize();
    }

    public void NavigateToPage(string direction)
    {
        switch (direction)
        {
            case "next":
                if (_page < _pages)
                {
                    _page += 1;
                }
                break;
            case "previous":
                if (_page > 1)
                {
                    _page -= 1;
                }
                break;
        }

        UpdateList(_page);
    }
}