Passing a simple string to component controller is returning null. I have already read this post but it didn't seem to imitate what I'm doing here. Pass value from apex component to controller

This article I just found. How do i pass data from visualforce page to component's custom controller? I'm trying to do this, but I don't need an output value, I need the value accessible within the Constructor of the component controller. Is this possible?


Greetings salesforce warriors! I want to use fieldsets and pass in the api name of the fieldset into the functions of the component controller. This way I can reuse the components and modify the passin value to the name of fields that I want to use.

Problem w/ Code

When I attempt to passin a value from the ParentVFPage to the attribute passIn on the vf Component, the components controller is not receiving the value and only returning null.

VF Page (no controller)

I want to pass a string value from the page to the component.

<apex:page   lightningStylesheets="false" showHeader="false">
<div class="slds-p-around_x-small">
    <c:HB_BS_MenuItems />
    <div class="slds-p-around_x-small"></div>



VF Component

<apex:attribute type="string" name="passIn" assignTo="{!fieldNames}" description="field set name"></apex:attribute>

<apex:component controller="HB_BS_UserController" allowDML="true">
<div class="slds-card__body slds-card__body_inner">
                <apex:form id="ChangeUserDetails">
                                <apex:commandButton styleClass="slds-button slds-button_brand" action="{!save}" value="Save"/>
                                <apex:commandButton styleClass="slds-button slds-button_outline-brand"  action="{!save}" value="Cancel"/>
                    <apex:repeat value="{!fields}" var="f">
                        <div class="slds-form-element">
                            <label class="slds-form-element__label" for="text-input-id-53">{!f.label}</label>
                            <div class="slds-form-element__control slds-input-has-icon slds-input-has-icon_right">
                                <apex:inputField styleClass="slds-input" value="{!user[f.fieldPath]}"/>

Component Controller

 public with sharing class HB_BS_UserController {
    public User user {get;set;} 
    public String fieldNames; 
    public String getfieldNames(){
        return fieldNames;
    public void setfieldNames(String s){
        fieldNames = s; 

    public HB_BS_UserController() {
        this.user = getUser();
    // User Fields 
    public List<Schema.FieldSetMember> getFields(){
        return SObjectType.User.FieldSets.HB_BS_UserAboutCard.getFields();

    public  User  getUser(){
        String query = 'SELECT ';
        String userId = UserInfo.getUserId();  
        for(Schema.FieldSetMember f : this.getFields()){
            query += f.getFieldPath() + ', '; 
        query += 'Id FROM User WHERE Id =: userId LIMIT 1'; 
        return Database.query(query);  


    public void save(){
        update user; 


The fieldNames value returns null.

1 Answer 1


I'm surprised the VF page even compiled because you have ..

<apex:attribute type="string" name="passIn" assignTo="{!fieldNames}" description="field set name"></apex:attribute>

<apex:component controller="HB_BS_UserController" allowDML="true">

apex:attribute has to be a child of apex:component. You want:

<apex:component controller="HB_BS_UserController" allowDML="true">
  <apex:attribute type="string" name="passIn" assignTo="{!fieldNames}" description="field set name"></apex:attribute>

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