Paging in Vue Treegrid component

24 Mar 20238 minutes to read

Paging provides an option to display TreeGrid data in page segments. To enable paging, set the allowPaging to true. When paging is enabled, pager component renders at the bottom of the treegrid. Paging options can be configured through the pageSettings.

To use paging, inject the Page module in the grid.

app.vue

<template>
<div id="app">
        <ejs-treegrid :dataSource='data' childMapping='subtasks' :treeColumnIndex='1' :allowPaging='true' :pageSettings='pageSettings'>
            <e-columns>
                <e-column field='taskID' headerText='Task ID' width='90' textAlign='Right'></e-column>
                <e-column field='taskName' headerText='Task Name' width='160'></e-column>
                <e-column field='startDate' headerText='Start Date' width='90' format="yMd" textAlign='Right'></e-column>
                <e-column field='duration' headerText='Duration' width='80' textAlign='Right'></e-column>
            </e-columns>
        </ejs-treegrid>
</div>
</template>
<script>
import Vue from "vue";
import { TreeGridPlugin, Page } from "@syncfusion/ej2-vue-treegrid";
import { sampleData } from "./datasource.js";

Vue.use(TreeGridPlugin);

export default {
  data ()  {
    return {
      data: sampleData,
      pageSettings: { pageSize: 7 }
    };
  },
  provide: {
      treegrid: [ Page ]
    }
}
</script>

You can achieve better performance by using treegrid paging to fetch only a pre-defined number of records from the data source.

Page Size Mode

Two behaviors are available in TreeGrid paging to display certain number of records in a current page. Following are the two types of pageSizeMode.

• All : This is the default mode. The number of records in a page is based on pageSize property.
• Root : The number of root nodes or the 0th level records to be displayed per page is based on pageSize property.

With pageSizeMode property as Root, only the root level or the 0th level records are considered in records count.

app.vue

<template>
<div id="app">
        <ejs-treegrid :dataSource='data' childMapping='subtasks' :treeColumnIndex='1' :allowPaging='true' :pageSettings='pageSettings' height='265px' >
            <e-columns>
                <e-column field='taskID' headerText='Task ID' width='90' textAlign='Right'></e-column>
                <e-column field='taskName' headerText='Task Name' width='160'></e-column>
                <e-column field='startDate' headerText='Start Date' width='90' format="yMd" textAlign='Right'></e-column>
                <e-column field='duration' headerText='Duration' width='80' textAlign='Right'></e-column>
            </e-columns>
        </ejs-treegrid>
</div>
</template>
<script>
import Vue from "vue";
import { TreeGridPlugin, Page } from "@syncfusion/ej2-vue-treegrid";
import { sampleData } from "./datasource.js";

Vue.use(TreeGridPlugin);

export default {
  data ()  {
    return {
      data: sampleData,
      pageSettings: { pageSize: 2, pageSizeMode: 'Root'}
    };
  },
  provide: {
      treegrid: [ Page ]
    },
}
</script>

Pager with Page Size Dropdown

The pager Dropdown allows you to change the number of records in the TreeGrid dynamically. It can be enabled by defining the pageSettings.pageSizes property as true.

pageSettings: {pageSize: 7, pageSizes: true},

How to render Pager at the Top of the TreeGrid

By default, Pager will be rendered at the bottom of the TreeGrid. You can also render the Pager at the top of the TreeGrid by using the dataBound event.

app.vue

<template>
<div id="app">
        <ejs-treegrid ref='treegrid' :dataSource='data' childMapping='subtasks' :treeColumnIndex='1' :allowPaging='true' :pageSettings='pageSettings' :dataBound='ondataBound'>
            <e-columns>
                <e-column field='taskID' headerText='Task ID' width='90' textAlign='Right'></e-column>
                <e-column field='taskName' headerText='Task Name' width='160'></e-column>
                <e-column field='startDate' headerText='Start Date' width='90' format="yMd" textAlign='Right'></e-column>
                <e-column field='duration' headerText='Duration' width='80' textAlign='Right'></e-column>
            </e-columns>
        </ejs-treegrid>
</div>
</template>
<script>
import Vue from "vue";
import { TreeGridPlugin, TreeGridComponent,  Page } from "@syncfusion/ej2-vue-treegrid";
import { sampleData } from "./datasource.js";

Vue.use(TreeGridPlugin);

let initialGridLoad = true;

export default {
  data ()  {
    return {
      data: sampleData,
      pageSettings: { pageSize: 7, pageSizes: true },
      initialGridLoad : true
      };
  },
  provide: {
      treegrid: [ Page ]
    },
     methods: {
    ondataBound: function() {
      if (this.initialGridLoad) {
          this.initialGridLoad = false;
          let pager = document.getElementsByClassName('e-gridpager e-control e-pager e-lib');
          let topElement;
         if ( this.$refs.treegrid.toolbar) {
             topElement = document.getElementsByClassName('e-toolbar');
        } else {
          topElement = document.getElementsByClassName('e-gridheader e-lib e-droppable');
        }
          topElement[0].before(pager[0]);
      }
    }
}
}
</script>

During the paging action, the pager component triggers the below three events.

• The created event triggers when Pager is created.
• The click event triggers when the numeric items in the pager is clicked.
• The dropDownChanged event triggers when pageSize DropDownList value is selected.