I created a lwc component that sends information about Opportunity.


The problem is that the data is written to Single Email only if I use 4 functions.  
1. handleToNameReceiverChange
2. handleToEmailAddressChange
3. handleToEmailSubjectChange
4. handleToEmailBodyChange

They work so that if I change the value of the field manually, the data is put into Email. If I don't change them, I get an undefined error and that the body is required in Email.


If I change the data in the fields manually, such as writing forexample , it works fine.



I want the fields to be taken as I specified in the queries, so that the Name of receiver, email, email subject were readonly and entered automatically in a single email. And the body remains editable.

Help me please.

SendInvoiceService.apxc

public with sharing class SendInvoiceService {
  //  @AuraEnabled
  //  public static List<ContentVersion> getPreview(id oppIds) {
   //     Opportunity oppor = [SELECT Id, Invoice_Number__c From Opportunity where id=:oppIds];
   //   return [SELECT Id, Title, FileExtension, ContentDocumentId From ContentVersion where title=:oppor.Invoice_Number__c];
   // }
    @AuraEnabled
    public static List<ContentDocument> getPreview(id oppIds) {
        try {
            Opportunity Opportunitys = [
                select id,Invoice_Number__c
                from Opportunity
                where id=:oppIds];
            
            List<ContentVersion> cvs = [SELECT Id, Title, FileExtension, ContentDocumentId From ContentVersion where Title=:Opportunitys.Invoice_Number__c];
            
            return [select Id from ContentDocument where LatestPublishedVersionId in :cvs];
        } catch (Exception e) {
            throw new AuraHandledException(e.getMessage());
        }
    }
    
      @AuraEnabled(cacheable=true)
    public static SendInvoice__c getInvoice(id oppId) {
        Opportunity Opportunity=[select id,Invoice_Number__c,
                                 (select IsPrimary,Contact.Email,Contact.AccountId,Contact.FirstName
                                  from OpportunityContactRoles where IsPrimary=true)
                                 from Opportunity where id=:oppId];
        OpportunityContactRole oppCR=Opportunity.OpportunityContactRoles;
        
        SendInvoice__c invoice=new SendInvoice__c();
        invoice.Body__c=[select body from EmailTemplate where name='OppTextAndr'].body+' body';
        invoice.Subject__c=Opportunity.Invoice_Number__c;
        invoice.Email__c=oppCR.Contact.Email;
        invoice.FirstName__c=oppCR.Contact.FirstName;	
        system.debug(invoice.Body__c+' '+invoice.Subject__c+' '+invoice.Email__c+' '+invoice.FirstName__c
                     +' '+invoice.LastName__c+' '+invoice.AttachId__c);
        return invoice;
    }
    @AuraEnabled
    public static void sendEmail(List<String> toAddress, String subject, String body, String name, id oppId) {      
        Messaging.reserveSingleEmailCapacity(1);
        try{
            
            messaging.SingleEmailMessage mail = new messaging.SingleEmailMessage();
            System.debug(toAddress);
            System.debug(body);
            System.debug(name);
            System.debug(subject);
            
            mail.setToAddresses(toAddress);
            mail.setReplyTo('no-reply@xooa.com');
            mail.setSenderDisplayName(name);
            mail.setSubject(subject);
            mail.setPlainTextBody(body);
            
            Messaging.sendEmail(new List<messaging.SingleEmailMessage> {mail});
        }
        catch (exception e){
            throw new AuraHandledException(e.getMessage());
        }
    }
}

SendInvoiceLWC.html

<template>  
<lightning-card title="Send Invoice" >
<lightning-input type="name" name="nameReceiver" label="Name of Receiver" onchange={handleToNameReceiverChange} value={realFormData.FirstName__c} if:true={realFormData} ></lightning-input>
<lightning-input type="email" name="emailAddress" label="Email" onchange={handleToEmailAddressChange}  value={realFormData.Email__c} if:true={realFormData} ></lightning-input>
<lightning-input type="emailsubject" name="emailSubject" onchange={handleToEmailSubjectChange}  label="EmailSubject" value={realFormData.Subject__c} if:true={realFormData}></lightning-input>
<lightning-input type="emailbody" name="emailBody" onchange={handleToEmailBodyChange} label="EmailBody" value={realFormData.Body__c} if:true={realFormData} ></lightning-input>
<lightning-button label="Show me PDF" onclick={openPDF}></lightning-button>
<lightning-button label="send Email" onclick={sendEmailHandler}></lightning-button> 
</lightning-card>

</template>

sendInvoiceLWC.js

import { LightningElement, api, wire, track } from 'lwc';
import getInvoice from '@salesforce/apex/SendInvoiceService.getInvoice';
import getPreview from '@salesforce/apex/SendInvoiceService.getPreview';
import sendEmail from '@salesforce/apex/SendInvoiceService.sendEmail';
import NAME_FIELD from '@salesforce/schema/SendInvoice__c.FirstName__c';
import SUBJECT_FIELD from '@salesforce/schema/SendInvoice__c.Subject__c';
import EMAIL_FIELD from '@salesforce/schema/SendInvoice__c.Email__c';
import BODY_FIELD from '@salesforce/schema/SendInvoice__c.Body__c';
import { getSObjectValue } from '@salesforce/apex';
import { NavigationMixin } from 'lightning/navigation';

export default class sendInvoiceLWC extends NavigationMixin(LightningElement) {
@track contents;
@track error;
@api recordId;



@track email = '';
@api wiredContact;
@api realFormData;
@api InvoiceObj;

@api wiredContent;
@api realFormContent;
@api PreviewObj;

@track content;
@track error;
@api contentVId;



 connectedCallback() {
  getPreview({ oppIds: this.recordId })
      .then((result) => {
        this.contents = result;
        this.error = undefined;
      })
      .catch((error) => {
        this.error = error;
        this.contents = undefined;
      });
  } 
  openPDF() {
    this[NavigationMixin.Navigate]({
      type: 'standard__namedPage',
      attributes: {
          pageName: 'filePreview'
      },
      state : {
          recordIds: '0695j000007MhNrAAK,0695j000007MhNrAAK',
          selectedRecordId:'0695j000007MhNrAAK'
      }
    })
  }

    
@wire(getInvoice, { oppId:'$recordId' }) fetchedInvoice( resp){
  this.wiredContact = resp;
  this.realFormData = this.wiredContact.data;
  this.InvoiceObj=resp;
  }
  get Subject() {
  return this.InvoiceObj.data?getSObjectValue(this.InvoiceObj.data,SUBJECT_FIELD,EMAIL_FIELD,BODY_FIELD,NAME_FIELD):'nothing';
  }

handleToNameReceiverChange(event) {
if (event.target.name === 'nameReceiver') {
  this.name = event.target.value;
  
}
}
handleToEmailAddressChange(event) {
if (event.target.name === 'emailAddress') {
  this.email = event.target.value;
}
}
handleToEmailSubjectChange(event) {
if (event.target.name === 'emailSubject') {
  this.emailsubject = event.target.value;
}
}
handleToEmailBodyChange(event) {
if (event.target.name === 'emailBody') {
  this.emailbody = event.target.value;
}
}


sendEmailHandler(event) {
  
console.log("Sending email to", this.email);
console.log("Email subject this subject", this.emailsubject);
console.log("Email body this body", this.emailbody);
sendEmail({ toAddress: this.email, subject: this.emailsubject, name: this.name, body: this.emailbody});
}
}

xml

<?xml version="1.0" encoding="UTF-8"?>
<LightningComponentBundle xmlns="http://soap.sforce.com/2006/04/metadata">
    <apiVersion>52.0</apiVersion>
    <isExposed>true</isExposed>
    <targets>
        <target>lightning__RecordAction</target>
    </targets>
    <targetConfigs>
        <targetConfig targets="lightning__RecordAction">
            <actionType>ScreenAction</actionType>
        </targetConfig>
    </targetConfigs>
</LightningComponentBundle>

help me please!!!