JavaScript/jQuery DataGrid - columns.lookup

A lookup column restricts the set of values that can be chosen when a user edits or filters the column. In a lookup column, each cell is a drop-down menu. You can use a lookup column when you need to substitute displayed values with required values. For example, consider that you have two arrays of objects: drivers and buses.

const drivers = [
    { driverID: 1, firstName: "John", lastName: "Smith", busID: 2 },
    { driverID: 2, firstName: "Lizzy", lastName: "Cook", busID: 1 },
    { driverID: 3, firstName: "Brian", lastName: "Hawkins", busID: 3 }
];

const buses = [
    { busID: 1, plates: "123456" },
    { busID: 2, plates: "AB-1234" },
    { busID: 3, plates: "CD-9876" }
];

All drivers have the busID field, which refers to a bus. If drivers is the main dataSource, the Bus ID column displays bus IDs, which provides little information to a user. It will be more useful to display bus license plates instead of IDs. For this, the buses array must be set as a lookup dataSource for the Bus ID column. Then, the names of data fields must be assigned to the valueExpr and displayExpr properties. Values from the valueExpr data field will be replaced with values from the displayExpr data field.

$(function() {
    $("#dataGridContainer").dxDataGrid({
        dataSource: drivers,
        // ...
        columns: [{
            dataField: "busID",
            lookup: {
                dataSource: buses,
                valueExpr: "busID",
                displayExpr: "plates"
            }
        }]
    });
});

<dx-data-grid [dataSource]="drivers">
    <dxi-column dataField="busID">
        <dxo-lookup
            [dataSource]="buses"
            valueExpr="busID"
            displayExpr="plates">
        </dxo-lookup>
    </dxi-column>
</dx-data-grid>

import { DxDataGridModule } from "devextreme-angular";
// ...
export class AppComponent {
    drivers = [
        { driverID: 1, firstName: "John", lastName: "Smith", busID: 2 },
        { driverID: 2, firstName: "Lizzy", lastName: "Cook", busID: 1 },
        { driverID: 3, firstName: "Brian", lastName: "Hawkins", busID: 3 }
    ];
    buses = [
        { busID: 1, plates: "123456" },
        { busID: 2, plates: "AB-1234" },
        { busID: 3, plates: "CD-9876" }
    ];
}
@NgModule({
    imports: [
        // ...
        DxDataGridModule
    ],
    // ...
})

<template>
    <DxDataGrid ...
        :data-source="drivers">
        <DxColumn data-field="busID">
            <DxLookup
                :data-source="buses"
                value-expr="busID"
                display-expr="plates"
            />
        </DxColumn>
    </DxDataGrid>
</template>

<script>
import 'devextreme/dist/css/dx.light.css';

import DxDataGrid, {
    DxColumn,
    DxLookup
} from 'devextreme-vue/data-grid';

const drivers = [
    { driverID: 1, firstName: "John", lastName: "Smith", busID: 2 },
    { driverID: 2, firstName: "Lizzy", lastName: "Cook", busID: 1 },
    { driverID: 3, firstName: "Brian", lastName: "Hawkins", busID: 3 }
];

const buses = [
    { busID: 1, plates: "123456" },
    { busID: 2, plates: "AB-1234" },
    { busID: 3, plates: "CD-9876" }
];

export default {
    components: {
        DxDataGrid,
        DxColumn,
        DxLookup
    },
    data() {
        return {
            drivers,
            buses
        }
    }
}
</script>

import React from 'react';
import 'devextreme/dist/css/dx.light.css';

import DataGrid, {
    Column,
    Lookup
} from 'devextreme-react/data-grid';

const drivers = [
    { driverID: 1, firstName: "John", lastName: "Smith", busID: 2 },
    { driverID: 2, firstName: "Lizzy", lastName: "Cook", busID: 1 },
    { driverID: 3, firstName: "Brian", lastName: "Hawkins", busID: 3 }
];

const buses = [
    { busID: 1, plates: "123456" },
    { busID: 2, plates: "AB-1234" },
    { busID: 3, plates: "CD-9876" }
];

export default function App() {
    return (
        <DataGrid ...
            dataSource={drivers}>
            <Column dataField="busID">
                <Lookup
                    dataSource={buses}
                    valueExpr="busID"
                    displayExpr="plates"
                />
            </Column>
        </DataGrid>
    );
}

With this code, the Bus ID column contains license plates instead of IDs. Moreover, the user can choose a plate number from the drop-down menu when editing cells or applying a filter to this column.

View Demo View on GitHub

See Also

• Bind a Lookup Column to a Custom Data Source
• Customize Editors
• Enhance Performance on Large Datasets - Lookup Optimization

Set this property to true only if your data source accepts null values.

To specify this property based on a condition, set the showClearButton property instead. This is a property of the SelectBox UI component which is used as an editor for lookup column cells. allowClearing is an alias for this property in the DataGrid. The following code shows how to set showClearButton in the onEditorPreparing event handler:

$(function() {
    $("#dataGridContainer").dxDataGrid({
        // ...
        onEditorPreparing: function (e) {
            if (/* a condition to set the property's value */) {
                e.editorOptions.showClearButton = true;
            }
        }
    });
});

import { Component } from '@angular/core';

@Component({
    selector: 'app-root',
    templateUrl: './app.component.html',
    styleUrls: ['./app.component.css']
})
export class AppComponent {
    onEditorPreparing(e) {
        if (/* a condition to set the property's value */) {
            e.editorOptions.showClearButton = true;
        }
    }
}

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { AppComponent } from './app.component';

import { DxDataGridModule } from 'devextreme-angular';

@NgModule({
    declarations: [
        AppComponent
    ],
    imports: [
        BrowserModule,
        DxDataGridModule
    ],
    bootstrap: [AppComponent]
})
export class AppModule { }

<dx-data-grid ...
    (onEditorPreparing)="onEditorPreparing($event)">
    <!-- ... -->
</dx-data-grid>

<template>
    <DxDataGrid ...
        :on-editor-preparing="onEditorPreparing">
        <!-- ... -->
    </DxDataGrid>
</template>

<script>
import 'devextreme/dist/css/dx.light.css';

import DxDataGrid from 'devextreme-vue/data-grid';

export default {
    components: {
        DxDataGrid
    },
    // ...
    methods: {
        onEditorPreparing(e) {
            if (/* a condition to set the property's value */) {
                e.editorOptions.showClearButton = true;
            }
        }
    }
}
</script>

import React from 'react';

import 'devextreme/dist/css/dx.light.css';

import DataGrid from 'devextreme-react/data-grid';

class App extends React.Component {
    onEditorPreparing(e) {
        if (/* a condition to set the property's value */) {
            e.editorOptions.showClearButton = true;
        }
    }

    render() {
        return (
            <DataGrid ...
                onEditorPreparing={this.onEditorPreparing}>
                {/* ... */}
            </DataGrid>
        );
    }
}
export default App;

This property accepts one of the following:

• Array of objects or primitives
  A JavaScript array that contains plain objects or primitives.

• DataSource configuration object
  A DataSource configuration object. You can find code for this example in the following help topic: Bind a Lookup Column to a Custom Data Source. For more information about the DataSource and DevExtreme Data Layer, refer to the Data Layer article.

  IMPORTANT

  DataSource instances are not supported.

• Store instance
  An ArrayStore, LocalStore, ODataStore, or CustomStore instance.

• Function
  A function that returns one of the above.

  NOTE

  When the component is initialized, it calls the dataSource function with an empty options object. To avoid execution errors, check that options properties are defined before accessing them. The following code snippet demonstrates how to check if options.data is defined before using the property in a filter expression:

  jQuery

  index.js

  $("#dataGridContainer").dxDataGrid({
      columns: [{
          lookup: {
              dataSource(options) {
                  return {
                      store: dataStore,
                      filter: options.data ? ['StateID', '=', options.data.StateID] : null,
                  };
              },
          }
      }]
  })

  Angular

  app.component.html

  app.component.ts

  <dx-data-grid ... >
      <dxi-column ... >
          <dxo-lookup [dataSource]="lookupDataSource" ... ></dxo-lookup>
      </dxi-column>
  </dx-data-grid>

  export class AppComponent {
      lookupDataSource = (options) => {
          return {
              store: this.dataStore,
              filter: options.data ? ['StateID', '=', options.data.StateID] : null,
          }
      }
  }

  Vue

  App.vue

  <script setup>
  import { DxDataGrid, DxColumn, DxLookup } from 'devextreme-vue/data-grid';
  
  const lookupDataSource = (options) => {
      return {
          store: dataStore,
          filter: options.data ? ['StateID', '=', options.data.StateID] : null,
      }
  }
  </script>
  
  <template>
      <DxDataGrid ... >
          <DxColumn ... >
              <DxLookup :dataSource="lookupDataSource" ... />
          </DxColumn>
      </DxDataGrid>
  </template>

  React

  App.js

  import { DataGrid } from 'devextreme-react';
  import { Column, Lookup } from 'devextreme-react/data-grid';
  
  function App() {
      function lookupDataSource(options) {
          return {
              store: dataStore,
              filter: options.data ? ['StateID', '=', options.data.StateID] : null,
          }
      }
      return (
          <>
              <DataGrid ... >
                  <Column ... >
                      <Lookup dataSource={lookupDataSource} ... />
                  </Column>
              </DataGrid>
          </>
      )
  }

If the lookup data source contains objects, specify the valueExpr and displayExpr properties in addition to the dataSource.

View Demo

This property accepts a string - the name of the data field that provides displayed values, or a function that returns the displayed value.

View Demo

Values from this data field must have the same type as the column's dataField values.

View Demo