Conditionally Render Input Fields from Component - Visualforce

Question

I am trying to figure out how to render a Visualforce component containing inputfields conditionally, depending on a stage field outside of the visualforce page. I would like to render a different visualforce component depending on the stage. Here's what I have so far. When I run as-is, I can't get anything to display within my visualforce page.

VF Page:

<apex:form >
   <c:StageFields record="{!opportunity}"  rendered="{!opportunity.StageName == 'Received'}" /> 
</apex:form>

Component:

 <apex:component>

    <apex:attribute name="record" type="Opportunity" description="Opportunity"/>
    <apex:inputField value="{!record.Rep_Name__c}"/>

</apex:component>

Answer 1

You'll want to pass the correct opportunity to the component so that your page's save method will work correctly. Usually, I pass the standard controller and/or record directly to the component. This requires some cooperation at the page level, like this:

public class StandardControllerExtension {
    public SObject record { get; set; }
    public ApexPages.StandardController standardController { get; set; }

    public StandardControllerExtension(ApexPages.StandardController controller) {
        record = controller.getRecord();
        standardController = controller;
    }
}

Which you can then add to your page:

<apex:page standardController="Opportunity" extensions="StandardControllerExtension">
    <apex:form >
         <c:StageFields record="{!record}" rendered="{!opportunity.StageName = 'Received'}" />
    </apex:form>
</apex:page>

And to your component:

<apex:component>
    <apex:attribute name="record" type="Opportunity" description="Opportunity"/>
    <apex:inputField value="{!record.Name}"/>
</apex:component>

Edit: The attribute wasn't formatted as a proper merge field, so it would cause the component to never render. I updated the code in this answer to correct that problem.

Answer 2

First you need to make your component parameter ready by passing Opportunity id so that you can query that and display opportunity details inside component or with your current implementation pass all required value from your visualforce page which you are displaying using your component in following way

<c:Stagefields opportunity="oppname"/>