# FlexGrid 101

This page shows how to get started with Wijmo's FlexGrid control.

## Getting Started

Steps for getting started with FlexGrid in JavaScript applications:

1. Add references to Wijmo.
2. Add markup to serve as the Wijmo control's host.
3. Initialize the Wijmo control(s) via JavaScript.
4. (Optional) Add some CSS to customize the FlexGrid control's appearance.

This will create a FlexGrid with default behavior, which includes automatic column generation, column sorting and reordering, editing, and clipboard support.

HTML
<div id="gsFlexGrid"></div>
JS
new wijmo.grid.FlexGrid('#gsFlexGrid', { itemsSource: data.getData(100) });
CSS
/* set default grid height and some shadow */ .wj-flexgrid { background-color: #fff; box-shadow: 4px 4px 10px 0 rgba(50, 50, 50, 0.75); height: 300px; margin-bottom: 12px; }

#### Result (live):

## Column Definitions

The Getting Started example did not define any columns, so FlexGrid generated them automatically.

This example shows how you can define the columns using the options parameter in the FlexGrid's constructor, or by adding items to the grid's columns collection at any time.

Specifying the columns allows you to choose which columns to show, and in what order. This also gives you control over each column's width, heading, formatting, alignment, and other properties.

In this case, we use star sizing to set the width of the "Country" column. This tells the column to stretch to fill the available width of the grid so there is no empty space. On the "Revenue" column, we set the format property to "n0", which results in numbers with thousand separators and no decimal digits.

HTML
<b>Constructor Options</b> <div id="cdInitMethod"></div> <b>Columns Collection</b> <div id="cdColsCollection"></div>
JS
// initialize a grid using an 'options' object new wijmo.grid.FlexGrid('#cdInitMethod', { autoGenerateColumns: false, columns: [ { header: 'Country', binding: 'country', width: '*' }, { header: 'Date', binding: 'date' }, { header: 'Revenue', binding: 'amount', format: 'n0' }, { header: 'Active', binding: 'active' }, ], itemsSource: data.getData(100) }); // initialize a second grid by setting properties var fgColsCollection = new wijmo.grid.FlexGrid('#cdColsCollection'); fgColsCollection.autoGenerateColumns = false; fgColsCollection.itemsSource = data.getData(100); // add columns one by one var c = new wijmo.grid.Column(); c.binding = 'country'; c.header = 'Country'; c.width = '*'; fgColsCollection.columns.push(c); c = new wijmo.grid.Column(); c.binding = 'date'; c.header = 'Date'; fgColsCollection.columns.push(c); c = new wijmo.grid.Column(); c.binding = 'amount'; c.header = 'Revenue'; c.format = 'n0'; fgColsCollection.columns.push(c); c = new wijmo.grid.Column(); c.binding = 'active'; c.header = 'Active'; fgColsCollection.columns.push(c);

#### Result (live):

Constructor Options
Columns Collection

## Selection Modes

By default, FlexGrid allows you to select a range of cells with the mouse or keyboard, just like Excel. The selectionMode property allows you to change that so that you can select a row, a range of rows, non-contiguous rows (like in a list-box), a single cell, or disable selection altogether.

This example allows you to pick the selectionMode from a Wijmo Menu control.

HTML
<div id="smFlexGrid"></div> <select id="smMenu"> <option value="None">None</option> <option value="Cell">Cell</option> <option value="CellRange" selected>CellRange</option> <option value="Row">Row</option> <option value="RowRange">RowRange</option> <option value="ListBox">ListBox</option> </select>
JS
var smFlexGrid= new wijmo.grid.FlexGrid('#smFlexGrid', { itemsSource: data.getData(100) }); var smMenu = new wijmo.input.Menu('#smMenu', { itemClicked: function (s) { smFlexGrid.selectionMode = s.selectedValue; udpateMenuHeader(s, 'Selection Mode'); } }); udpateMenuHeader(smMenu, 'Selection Mode');

#### Result (live):

## Editing

FlexGrid has built-in support for fast, in-cell editing like you find in Excel. There is no need to add extra columns with Edit buttons that switch between display and edit modes.

Users can start editing by typing into any cell. This puts the cell in quick-edit mode. In this mode, pressing a cursor key finishes the editing and moves the selection to a different cell.

Another way to start editing is by pressing F2 or by clicking a cell twice. This puts the cell in full-edit mode. In this mode, pressing a cursor key moves the caret within the cell text. To finish editing and move to another cell, the user must press the Enter, Tab, or Escape key.

Data is automatically coerced to the proper type when editing finishes. If the user enters invalid data, the edit is cancelled and the original data remains in place.

You can disable editing at the grid, column, or row levels using the isReadOnly property of the grid, column, or row objects. In this example, we make the ID column read-only.

HTML
<div id="eFlexGrid"></div>
JS
new wijmo.grid.FlexGrid('#eFlexGrid', { autoGenerateColumns: false, columns: [ { header: 'ID', binding: 'id', width: '*', isReadOnly: true }, // cannot edit { header: 'Country', binding: 'country' }, { header: 'Date', binding: 'date' }, { header: 'Revenue', binding: 'amount', format: 'n0' }, { header: 'Active', binding: 'active' }, ], itemsSource: data.getData(100) });

#### Result (live):

## Grouping

FlexGrid supports grouping through the ICollectionView interface, which is identical to the one in .NET. To enable grouping, add one or more GroupDescription objects to the CollectionView.groupDescriptions property, and ensure that the grid's showGroups property is set to true (the default value).

GroupDescription objects are flexible, allowing you to group data based on value or on grouping functions. The example below groups dates by year; amounts by range returning three ranges: over 5,000, 500 to 5,000, and under 500; other properties are grouped by value. Use the menu to see the effect of each grouping.

Notice that the "Revenue" column displays the totals in the group rows. We do this by setting the column's aggregate property to "Sum." The aggregate is automatically updated when you edit the values in the column.

HTML
<div id="gFlexGrid"></div> <select id="gMenu"> <option value="" selected>(no grouping)</option> <option value="country">Country</option> <option value="amount">Revenue</option> <option value="date">Date</option> <option value="country,date">Country and Date</option> <option value="country,amount">Country and Revenue</option> <option value="country,date,amount">Country, Date, and Revenue</option> </select>
JS
var gFlexGrid = new wijmo.grid.FlexGrid('#gFlexGrid', { autoGenerateColumns: false, columns: [ { header: 'Country', binding: 'country', width: '*' }, { header: 'Date', binding: 'date' }, { header: 'Revenue', binding: 'amount', format: 'n0' } ], itemsSource: data.getData(100) }); var gMenu = new wijmo.input.Menu('#gMenu', { itemClicked: function (sender) { // clear any current groups var gds = gFlexGrid.collectionView.groupDescriptions; gds.clear(); // add new group var groupBy = sender.selectedValue; if (groupBy) { var groupNames = groupBy.split(','); for (var i = 0; i < groupNames.length; i++) { var groupName = groupNames[i]; if (groupName == 'date') { // group dates by year var groupDesc = new wijmo.collections.PropertyGroupDescription(groupName, function (item, prop) { return item.date.getFullYear(); }); gds.push(groupDesc); } else if (groupName == 'amount') { // group amounts in ranges var groupDesc = new wijmo.collections.PropertyGroupDescription(groupName, function (item, prop) { return item.amount >= 5000 ? '> 5,000' : item.amount >= 500 ? '500 to 5,000' : '< 500'; }); gds.push(groupDesc); } else { // group everything else by value var groupDesc = new wijmo.collections.PropertyGroupDescription(groupName); gds.push(groupDesc); } } } udpateMenuHeader(s, 'Group By'); } }); udpateMenuHeader(gMenu, 'Group By');

#### Result (live):

## Filtering

The FlexGrid supports filtering through the ICollectionView interface, which is identical to the one in .NET. To enable filtering, set the CollectionView.filter property to a function that determines which objects to include in the view.

In this example, we create a filter for the country, and get the filter value from the input control.

HTML
<div id="fFlexGrid"></div> <div class="input-group"> <span class="input-group-addon"> <i class="glyphicon glyphicon-filter"></i> </span> <input id="fFilter" type="text" class="form-control" placeholder="Filter by Country..." /> </div>
JS
var fFlexGrid = new wijmo.grid.FlexGrid('#fFlexGrid', { itemsSource: data.getData(100) }); // apply a filter to the grid's CollectionView var filterText = ''; fFlexGrid.collectionView.filter = function (item) { return filterText ? item.country.toLowerCase().indexOf(filterText) > -1 : true; } // refresh filter when text changes document.getElementById('fFilter').addEventListener('input', function (e) { filterText = e.target.value.toLowerCase(); fFlexGrid.collectionView.refresh(); });

#### Result (live):

## Paging

The FlexGrid supports paging through the IPagedCollectionView interface, which is nearly identical to the one in .NET. To enable paging, set the IPagedCollectionView.pageSize property to the number of items you want on each page, and provide a UI for navigating the pages.

In this example, we use JavaScript to show 10 items per page. We add navigation buttons, and call IPagedCollectionView methods when a button is clicked. We use the pageIndex and pageCount properties to show the current page and total number of pages.

HTML
<div id="pFlexGrid" style="height:auto"></div> <div class="btn-group" id="pPager"> <button id="btnPageFirst" class="btn btn-default"> <span class="glyphicon glyphicon-fast-backward"></span> </button> <button id="btnPagePrev" class="btn btn-default"> <span class="glyphicon glyphicon-step-backward"></span> </button> <button id="btnPageCurrent" class="btn btn-default" disabled style="width:100px"></button> <button id="btnPageNext" class="btn btn-default"> <span class="glyphicon glyphicon-step-forward"></span> </button> <button id="btnPageLast" class="btn btn-default"> <span class="glyphicon glyphicon-fast-forward"></span> </button> </div>
JS
var pFlexGrid = new wijmo.grid.FlexGrid('#pFlexGrid', { itemsSource: data.getData(100) }); // set page size to 10 var cvPaged = pFlexGrid.collectionView; cvPaged.pageSize = 10; cvPaged.pageChanged.addHandler(function () { updatePager(cvPaged); }); updatePager(cvPaged); // handle pager buttons onClick('btnPageFirst', function () { cvPaged.moveToFirstPage(); }); onClick('btnPagePrev', function () { cvPaged.moveToPreviousPage(); }); onClick('btnPageNext', function () { cvPaged.moveToNextPage(); }); onClick('btnPageLast', function () { cvPaged.moveToLastPage(); }); // disable/enable buttons and update display text for pager function updatePager(cv) { var firstPage = cv.pageIndex <= 0; disable('btnPageFirst', firstPage); disable('btnPagePrev', firstPage); var lastPage = cv.pageIndex >= cv.pageCount - 1; disable('btnPageNext', lastPage); disable('btnPageLast', lastPage); setText('btnPageCurrent', (cv.pageIndex + 1) + ' / ' + (cv.pageCount)); }

#### Result (live):

## Master-Detail

The ICollectionView interface has built-in support for currency, which enables you to implement master-detail scenarios with FlexGrid. You can refer to the currentItem and use it as a binding source for any elements on the page.

Note that you have to update the details view when the current item changes. To do that, attach a handler to the ICollectionView.currentChanged event and update the details view as needed.

HTML
<div id="mdFlexGrid"></div> <dl class="dl-horizontal"> <dt>ID</dt> <dd id="mdCurId"></dd> <dt>Country</dt> <dd id="mdCurCountry"></dd> <dt>Date</dt> <dd id="mdCurDate"></dd> <dt>Revenue</dt> <dd id="mdCurRevenue"></dd> <dt>Active</dt> <dd id="mdCurActive"></dd> </dl>
JS
var mdFlexGrid = new wijmo.grid.FlexGrid('#mdFlexGrid', { selectionMode: 'Row', itemsSource: data.getData(100) }); // update detail pane now and when the current item changes updateDetails(); mdFlexGrid.collectionView.currentChanged.addHandler(updateDetails); // update the details when the CollectionView's currentItem changes function updateDetails() { var cv = mdFlexGrid.collectionView, item = cv.currentItem; setText('mdCurId', item.id); setText('mdCurCountry', item.country); setText('mdCurDate', wijmo.Globalize.format(item.date, 'd')); setText('mdCurRevenue', wijmo.Globalize.format(item.amount, 'c')); setText('mdCurActive', item.active); }

#### Result (live):

ID
Country
Date
Revenue
Active

## Conditional Styling

FlexGrid has a formatItem event that gives you complete control over the contents of the cells.

This example adds a handler to the formatItem event that changes the color of cells in the 'amount' column to reflect the cell value. Small numbers are shown in red, large numbers in green.

HTML
<div id="csFlexGrid"></div>
JS
new wijmo.grid.FlexGrid('#csFlexGrid', { autoGenerateColumns: false, columns: [ { header: 'Country', binding: 'country', width: '*', isContentHtml: true, isReadOnly: true }, { header: 'Date', binding: 'date' }, { header: 'Revenue', binding: 'amount', format: 'n0' }, { header: 'Active', binding: 'active' }, ], formatItem: function (s, e) { // we are only interested in regular (scrollable) cells if (e.panel == s.cells) { // compute the cell color (for all columns, since cells may be recycled) var color = ''; if (s.columns[e.col].binding == 'amount') { var amount = e.panel.getCellData(e.row, e.col); color = amount < 500 ? 'red' : amount < 2500 ? 'black' : 'green'; } // always set the color e.cell.style.color = color; } }, itemsSource: data.getData(100) });

#### Result (live):

## Themes

The appearance of the FlexGrid is defined in CSS. In addition to the default theme, we include about a dozen professionally designed themes that customize the appearance of all Wijmo controls to achieve a consistent, attractive look.

You can customize the appearance of the grid using CSS. To do this, copy CSS rules from the default theme to a new CSS file and modify the style attributes you want to change.

In this example, we add a "custom-flex-grid" class to the grid element and define some CSS rules to create a simple "black and white, no borders" theme for any grids that have the "custom-flex-grid" class.

HTML
<div id="tFlexGrid" class="custom-flex-grid"></div>
JS
new wijmo.grid.FlexGrid('#tFlexGrid', { itemsSource: data.getData(100) });
CSS
/* 'custom-flex-grid' theme for the FlexGrid */ .custom-flex-grid .wj-header.wj-cell { color: #fff; background-color: #000; border-bottom: solid 1px #404040; border-right: solid 1px #404040; font-weight: bold; } .custom-flex-grid .wj-cell { background-color: #fff; border: none; } .custom-flex-grid .wj-alt:not(.wj-state-selected):not(.wj-state-multi-selected) { background-color: #fff; } .custom-flex-grid .wj-state-selected { background: #000; color: #fff; } .custom-flex-grid .wj-state-multi-selected { background: #222; color: #fff; }

#### Result (live):

## Trees and Hierarchical Data

In addition to grouping, FlexGrid supports hierarchical data, that is, data with items that have lists of subitems. This type of hierarchical structure is very common, and is usually displayed in a tree-view control.

To use FlexGrid with hierarchical data sources, set the childItemsPath property to the name of the data element that contains the child elements. The grid automatically scans the data and builds the tree for you.

HTML
<div id="tvFlexGrid" class="custom-flex-grid"></div>
JS
new wijmo.grid.FlexGrid('#tvFlexGrid', { autoGenerateColumns: false, columns: [ { binding: 'name', width: '*' }, { binding: 'length', width: 80, align: 'center' } ], itemsSource: data.treeData, // hierarchical data childItemsPath: 'items', // set hierarchy path allowResizing: 'None', // disable resizing headersVisibility: 'None', // hide headers selectionMode: 'ListBox' // use ListBox selection });
CSS
/* 'custom-flex-grid' theme for the FlexGrid */ .custom-flex-grid .wj-header.wj-cell { color: #fff; background-color: #000; border-bottom: solid 1px #404040; border-right: solid 1px #404040; font-weight: bold; } .custom-flex-grid .wj-cell { background-color: #fff; border: none; } .custom-flex-grid .wj-alt:not(.wj-state-selected):not(.wj-state-multi-selected) { background-color: #fff; } .custom-flex-grid .wj-state-selected { background: #000; color: #fff; } .custom-flex-grid .wj-state-multi-selected { background: #222; color: #fff; }

#### Result (live):

## Handling nulls

By default, FlexGrid allows you to enter empty values in columns of type string, and will not allow empty/null values in columns of any other type.

You can change this behavior using the isRequired property on grid columns. If you set the isRequired property to false, the grid will allow you to enter empty values in that column, regardless of type. Conversely, if you set the isRequired property to true, the grid will not allow empty values even in string columns.

Setting isRequired to null reverts to the default behavior (nulls are allowed only in string columns).

The grid below reverts the default behavior. It sets isRequired to true for the first column and to false for all others. You can delete content that is not required by entering an empty string or simply by pressing the delete key.

HTML
<div id="nvGrid"></div>
JS
new wijmo.grid.FlexGrid('#nvGrid', { autoGenerateColumns: false, itemsSource: data.getData(100), columns: [ { header: 'Country', binding: 'country', width: '*', isRequired: true }, { header: 'Date', binding: 'date', isRequired: false }, { header: 'Revenue', binding: 'amount', format: 'n0', isRequired: false }, { header: 'Active', binding: 'active', isRequired: false } ] });

#### Result (live):