How to pass an object parameter to APEX controller from LWC

Question

I'm creating a custom lead conversion page, I'm trying to pass the lead to an apex controller, I think the problem I guess is when the 'handleConvert' function in js is called, the variable varLeadRecord is not recognized by the apex.

Here is my js controller:

import { LightningElement, api, wire, track } from 'lwc';
import getLeadRecord from '@salesforce/apex/apexController.getLeadRecord';
import convertLead from '@salesforce/apex/apexController.convertLead';    

export default class CustomLeadConversion extends LightningElement {
    @api recordId; 
    @track isNewAccount = true;
    @track isNewContact = true;
    @track isNewOpp = true;
    @track varLeadRecord = {};

    @wire(getLeadRecord, { leadId : '$recordId' })
    leadRecordDetails({ data, error }){
        if(data){
            this.varLeadRecord = data;
            console.log('this.varLeadRecord please');
            console.log(this.varLeadRecord);
            console.log(this.varLeadRecord.Name);
            console.log(this.varLeadRecord.Id);
        }else if(error){

        }
    }  
        
    handleConvert(){
        console.log('convert button is clicked'); //this is OK
        console.log(this.varLeadRecord); //
        convertLead({leadRec: '$this.varLeadRecord'})
        .then(result => {
            console.log(result);
        })
        .catch(error => {
            this.error = error;
        });
    }
}

Here is my APEX controller

public class apexController{
    @AuraEnabled(cacheable=true)
    public static Lead getLeadRecord(String leadId) {   
        System.debug('leadId ' + leadId);
        
        Lead leadRec;
        List<Lead> leadList = [SELECT Id, Name, Salutation, FirstName, LastName FROM Lead WHERE Id =: leadId];
        System.debug('leadList ' + leadList);
        if(leadList !=null && !leadList.isEmpty()){
            return leadList[0];
        }
        return leadRec;       
    }   
    
   @AuraEnabled(cacheable=true)
    public static String convertLead(Lead leadRec){
        System.debug('convert lead');
        return 'converted';
        
    }
}
 

Answer 1

In the imperative apex call, you don't need to use the "$varLeadRecord"(This format is used only for wire calls). format. Simply use this.varLeadRecord without any quotes (This does not work with wired calls).

handleConvert(){
    console.log('convert button is clicked'); //this is OK
    console.log(this.varLeadRecord); //
    convertLead({leadRec: this.varLeadRecord})
    .then(result => {
        console.log(result);
    })
    .catch(error => {
        this.error = error;
    });
}