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How To Implement Infinity Or Lazy Loading In Salesforce Lightning DataTable

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Hi guys welcome back, Today in this post we are going to learn how we can implement infinity or lazy loading in salesforce ‘lightning:datatable’ lightning component using offset feature.

lazy loading lightning datatble

From developer console >> file >> new >> Apex Class

Apex Class : AccountTableController.apxc
/*
* Date : 3/4/2019
* API : 45
* Source : sfdcMonkey.com
*/
public class AccountTableController {
    
    //To return initial account records
    @AuraEnabled
    public static AccountWrapper getAccountRecords(Integer initialRows){
        AccountWrapper accountWrapper= new AccountWrapper();
        try{
            accountWrapper.accountsList = [SELECT ID,Name,Rating,AccountSource FROM Account ORDER BY Name ASC LIMIT :initialRows OFFSET 0];
            accountWrapper.totalRecords = [SELECT COUNT() FROM Account];
            accountWrapper.message = 'Account records are loaded';
            accountWrapper.success = true;
        }
        catch(Exception e){
            accountWrapper.message = e.getMessage();
            accountWrapper.success = false;
        }
        return accountWrapper;
    }
    
    //To return additional records based on offset
    @AuraEnabled
    public static List<Account> loadAccountRecords(Integer rowLimit,Integer rowOffset){
        return [SELECT ID,Name,Rating,AccountSource FROM Account ORDER BY Name ASC LIMIT :rowLimit OFFSET :rowOffset];
    }
    
    // wrapper class
    public class AccountWrapper{
        @AuraEnabled
        public Integer totalRecords = 0;
        @AuraEnabled
        public List<Account> accountsList = new List<Account>();
        @AuraEnabled
        public String message;
        @AuraEnabled
        public Boolean success;
    }
    
}

From developer console >> file >> new >> Lightning Component 

Lightning Component : infinityLoading.cmp
<!--
   Source : sfdcmonkey.com
   Date : 3/4/2019
   API : 45.0
-->
<aura:component controller="AccountTableController"
                implements="flexiPage:availableForAllPageTypes">
    
    <aura:handler name="init" value="{!this}" action="{!c.onInit}"/>
    
    <!--Aura Attributes START--> 
    <aura:attribute name="accountColums" type="List"/>
    <aura:attribute name="accountData" type="Object"/>
    <aura:attribute name="enableInfiniteLoading" type="Boolean" default="true"/>
    <aura:attribute name="initialRows" type="Integer" default="10"/>
    <aura:attribute name="currentCount" type="Integer" default="10"/>
    <aura:attribute name="totalRows" type="Integer" default="0"/>
    <aura:attribute name="loadOffset" type="Integer" default="1"/><!--Set when to trigger loading of more rows-->
    <!--Aura Attributes END--> 
    
    <div class="slds-page-header" role="banner">
        <span class="slds-page-header__title">Accounts List</span>
    </div>
    
    <!--Lightning data table markup-->
    <div style="height:250px">
        <lightning:datatable aura:id="dataTableID"
                             keyField="Id"
                             hideCheckboxColumn="true"
                             columns="{!v.accountColums}"
                             data="{!v.accountData}"
                             enableInfiniteLoading="{!v.enableInfiniteLoading}"
                             loadMoreOffset="{!v.loadOffset}"
                             onloadmore="{!c.handleLoadMore}"/>
    </div>
</aura:component>
JavaScript Controller : infinityLoadingController.js
/*
 * Date : 3/4/2019 * API : 45 
 * Source : sfdcMonkey.com 
*/
({
    onInit : function(component,event,helper){
        //Setting up colum information
        component.set("v.accountColums",
                      [
                          {
                              label : 'Name',
                              fieldName : 'accountName',
                              type : 'url',
                              typeAttributes:{label:{fieldName:'Name'},target:'_blank'}
                          },
                          {
                              label : 'Account Source',
                              fieldName : 'AccountSource',
                              type : 'text',
                          },
                          {
                              label : 'Rating',
                              fieldName : 'Rating',
                              type : 'text',
                          }
                      ]);
        // Call helper to set the data for account table
        helper.getData(component);
    },
    
    handleLoadMore : function(component,event,helper){
        if(!(component.get("v.currentCount") >= component.get("v.totalRows"))){
            //To display the spinner
            event.getSource().set("v.isLoading", true); 
            //To handle data returned from Promise function
            helper.loadData(component).then(function(data){ 
                var currentData = component.get("v.accountData");
                var newData = currentData.concat(data);
                component.set("v.accountData", newData);
                //To hide the spinner
                event.getSource().set("v.isLoading", false); 
            });
        }
        else{
            //To stop loading more rows
            component.set("v.enableInfiniteLoading",false);
            event.getSource().set("v.isLoading", false);
            var toastReference = $A.get("e.force:showToast");
            toastReference.setParams({
                "type":"Success",
                "title":"Success",
                "message":"All Account records are loaded",
                "mode":"dismissible"
            });
            toastReference.fire();
        }
    },
    
})
JavaScript Helper: infinityLoadingHelper.js
/*
 * Date : 3/4/2019
 * API : 45
 * Source : sfdcMonkey.com 
*/
({
    getData : function(component){
        // call apex class method
        var action = component.get("c.getAccountRecords");
        action.setParams({
            "initialRows" : component.get("v.initialRows") //how many rows to load during initialization
        });
        action.setCallback(this,function(response){
            var state = response.getState();
            var toastReference = $A.get("e.force:showToast");
            if(state == "SUCCESS"){
                var accountWrapper = response.getReturnValue();
                if(accountWrapper.success){
                    // set total rows count from response wrapper
                    component.set("v.totalRows",accountWrapper.totalRecords);  
                    
                    var accountList = accountWrapper.accountsList;
                    // play a for each loop on list of account and set Account URL in custom 'accountName' field
                    accountList.forEach(function(account){
                        account.accountName = '/'+account.Id;
                    });
                    // set the updated response on accountData aura attribute  
                    component.set("v.accountData",accountList);
                    // display a success message  
                    toastReference.setParams({
                        "type" : "Success",
                        "title" : "Success",
                        "message" : accountWrapper.message,
                        "mode" : "dismissible"
                    });
                    toastReference.fire();
                }
                else{ // if any server side error, display error msg from response
                    toastReference.setParams({
                        "type" : "Error",
                        "title" : "Error",
                        "message" : accountWrapper.message,
                        "mode" : "sticky"
                    }); 
                    toastReference.fire();
                }
            }
            else{ // if any callback error, display error msg
                toastReference.setParams({
                    "type" : "Error",
                    "title" : "Error",
                    "message" : 'An error occurred during Initialization '+state,
                    "mode" : "sticky"
                });
                toastReference.fire();
            }
        });
        $A.enqueueAction(action);
    },
    
    loadData : function(component){
        return new Promise($A.getCallback(function(resolve){
            var limit = component.get("v.initialRows");
            var offset = component.get("v.currentCount");
            var totalRows = component.get("v.totalRows");
            if(limit + offset > totalRows){
                limit = totalRows - offset;
            }
            var action = component.get("c.loadAccountRecords");
            action.setParams({
                "rowLimit" :  limit,
                "rowOffset" : offset
            });
            action.setCallback(this,function(response){
                var state = response.getState();
                var newData = response.getReturnValue();
                // play a for each loop on list of new accounts and set Account URL in custom 'accountName' field
                newData.forEach(function(account){
                    account.accountName = '/'+account.Id;
                });
                resolve(newData);
                var currentCount = component.get("v.currentCount");
                currentCount += component.get("v.initialRows");
                // set the current count with number of records loaded 
                component.set("v.currentCount",currentCount);
            });
            $A.enqueueAction(action);
        }));
    }
})

Check code comments.

Infinity Loading Component Output :

lazy loading lightning datatble

 

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Happy Learning ?

About The contributor: 

Kiran.B

3 Post Contribute

kiran b sfdcMonkey

I have 3.5 years of experience and working in lightning for the past 1 year. I am working as a developer in Deloitte.

Skills : Apex ,lightning , visualforce,sales cloud,JavaScript,Einstein analytics

 

 

Post By Kiran :

  1. How To Implement Infinity Or Lazy Loading In Salesforce Lightning DataTable
  2. How To Implement Column Sorting In Salesforce Lightning DataTable
  3. Develop a Simple To-Do List App With Salesforce Lightning Component

    2 comments

    • This is giving error as

      Error in $A.getCallback() [Cannot read property ‘setParams’ of undefined] Callback failed: apex://AccountTableController/ACTION$getAccountRecords Failing descriptor: {c:infinityLoading}

      Please help.

      Thank you!

    • I am getting following error,Please help.

      Error in $A.getCallback() [Cannot read property ‘setParams’ of undefined] Callback failed: apex://AccountTableController/ACTION$getAccountRecords Failing descriptor: {c:infinityLoading}

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