Displaying error message besides the field responsible for occurrence of error from Apex code

Question

I am trying to display a form that creates multiple Contact records from my Visualforce Page. I don't want to use inputField to achieve the same. The requirement is that if I do not enter LastName and click the Save button, the message should appear just besides the inputText field that I used to fill the LastName.

I cannot submit the form until all fields have been filled.

Right now the error message gets displayed against all the fields, even if I have filled all the fields, except one.

Markup

<apex:page Controller="AddTwoContactsController">
    <apex:form >
        <apex:pageBlock >
        <apex:pageBlockSection columns="1">

            <apex:pageBlockTable value="{!lstContacts}" var="con">
                <apex:column headerValue="Salutation">
                    <apex:inputField value="{!con.Salutation}"/>
                </apex:column>
                <apex:column headerValue="First Name">
                    <apex:inputText value="{!con.FirstName}" required="true"/>
                    <apex:messages />
                </apex:column>
                <apex:column headerValue="Last Name">
                    <apex:inputText value="{!con.LastName}" required="true"/>
                    <apex:messages />
                </apex:column>
            </apex:pageBlockTable>
            </apex:pageBlockSection>

            <apex:pageBlockSection columns="1">
            <apex:pageBlockTable value="{!lstContacts1}" var="con1">
                <apex:column headerValue="Salutation">
                    <apex:inputField value="{!con1.Salutation}"/>
                </apex:column>
                <apex:column headerValue="First Name">
                    <apex:inputText value="{!con1.FirstName}" required="true"/>
                    <apex:messages />
                </apex:column>
                <apex:column headerValue="Last Name">
                    <apex:inputText value="{!con1.LastName}" required="true"/>
                    <apex:messages />
                </apex:column>
            </apex:pageBlockTable>
             </apex:pageBlockSection>
            <apex:pageBlockButtons >

                <apex:commandButton value="Save Contacts" action="{!saveContact}"/>
            </apex:pageBlockButtons>
        </apex:pageBlock>
    </apex:form>
</apex:page>

Controller

public with sharing class AddTwoContactsController {


   // public String con1 { get; set; }

    //public String Contact { get; set; }



    Contact ct = new Contact();
    public List<Contact> lstContacts{ get; set; }
    Contact ct1=new Contact();
    public List<Contact> lstContacts1{ get;set; }

    public AddTwoContactsController ()
    {
        lstContacts=new list<Contact>();
        lstContacts.add(ct);
        lstContacts1=new list<Contact>();
        lstContacts1.add(ct1);
    }
    public PageReference saveContact() {
        for(Integer i=1; i<=lstContacts.size(); i++)
        {
            upsert lstContacts;
        }
        for(Integer j=1; j<=lstContacts1.size(); j++)
        {
            upsert lstContacts1;
        }
        return Page.Allcontactssaved;

    }

The output looks like:

Answer 1

There are many available strategies. Probably the simplest is to use the required attribute:

<apex:inputText value="{!Contact.LastName}" required="true" />

The advantage there is that you do not require any Apex at all. It also works with inputText, whereas other strategies depend on using inputField.

---

Another option is to make the field required at the database level or use a Validation Rule:

ISBLANK(LastName)

Again, no Apex.

---

If you want to add an error to a specific field in Apex, you can as follows:

contactRecord.LastName.addError('error message');

Note that this functionality cannot be achieved dynamically.