Display default picklist value as Read-only on Custom Object

Question

I am fairly new to Salesforce and recently came across an interesting problem for which I have been trying to find a solution. My app has a Custom Object called MyCustomObject__c with a VF named MyCustomObject.page that calls a the StandardController MyCustomObject and its extension MyCustomObjectControllerExt. The Custom Object has a picklist (MyPickList__c with 3 values: New, Active and Expired and whose default value is set to New on the picklist object. What I would like to achieve is to make the picklist defaulted to 'New' and Read-Only each time a new record is created (via the New Standard Salesforce button). I have first made the change to the Page Layout on the object by selecting the Read-Only option, however the user is still able to set whichever value they want to pick when creating a new record instance. I have then included the following code snippet in the VF:

  <apex:form>
    <apex:pageBlock>                            
        <apex:pageBlockSection columns="1" title="My Custom Object">
        <apex:outputField value="{!MyCustomObject__c.MyPickList__c}"  />                            
        </apex:pageBlockSection>
    </apex:pageBlock>
   <apex:form></code>

I am not sure, however, how the controller extension needs further adapting to set the picklist to the default value. Currently, it includes the following:

public MyCustomObjectExt(ApexPages.StandardController standardcontroller){ MyCustomObject__c customObject = new MyCustomObject__c(); customObject.MyPickList__c = 'New'; this.controller = standardcontroller; }

Am I leaning towards the right direction with this issue?

Thank you all for your help, much appreciated!

I.

Answer 1

As for the read-only aspect of your question, end users will not be able to modify the value on the page you have specified, as you are using an apex:outputField, which is read-only by default (it's the first thing mentioned in the documentation).

Here is how you would retrieve the deault programatically. Check out the Schema.PicklistEntry documentation, specifically isDefaultValue.

public class MyCustomObjectServices
{
    public static Schema.PicklistEntry myPicklistDefaultEntry
    {
        get
        {
            // Lazy load if you wish
            // You may prefer to return just the Label/Value
            for (Schema.PicklistEntry entry : myPickListEntries)
            {
                if (entry.isDefaultValue()) return entry;
            }
            return null;
        }
    }
    public static List<Schema.PicklistEntry> myPickListEntries
    {
        get
        {
            // Lazy load if you wish
            return MyCustomObject__c.MyPickList__c.
                getDescribe().getPicklistValues();
        }
    }
}

You could reference these in your controller with ease:

public MyCustomObjectExt(ApexPages.StandardController standardcontroller){
    MyCustomObject__c customObject = new MyCustomObject__c();
    customObject.MyPickList__c = MyCustomObjectServices.myPicklistDefaultEntry.getValue();
    this.controller = standardcontroller;
}