Custom Lookup Dynamically add fields to a table

Question

Hi i have been trying my hand at a custom lookup. So far i have it working perfectly fine, for one object. I am trying to make it as polymorphic as possible. Is there anyway to add columns to the table dynamically? So far i have yet to see anything that would help me. The apex:repeat seems like it would but i am unsure on how to use it. THe documentation doesn't feel suffice on it.

EDIT:

Yeah i am just looking for if you can take data from the controller and feed it to the table on runtime as oppose to having the pageblocktable set up prior to loading the content. Since I am using SObject, it says SObject.Name doesn't exist because of it. I am trying to make it so that this one table will load data for whatever the objectType is.

Answer 1

As others have comment what you are asking is not entirely clear. Here are two things you might be asking about...

Lookup fields are presently tied to a specific SObject type. So if you want an SObject to have lookup fields to several SObject types you will have to add multiple lookup fields.

If only one of them is ever populated, with controller code like this:

public with sharing MyController {
    ....
    public CustomObject__c sob {get; private set;}
    public String[] lookupFields {
        get {
            return new String [] {'A__c', 'B__c', 'C__c', 'D__c'};
        }
    }
}

the page can just present the populated field like this:

<apex:repeat values="{!lookupFields}" var="f">
    <apex:inputField value="{!sob[f]}" rendered="{!sob[f] != null}"
</apex:repeat>

The same technique - using field name strings - can be used to present a set of table columns dynamically:

public with sharing MyController {
    ....
    public CustomObject__c[] sobs {get; private set;}
    public String[] columns {
        get {
            return new String [] {'A__c', 'B__c', 'C__c', 'D__c'};
        }
    }
}

with the page containing this:

<apex:pageBlockTable value="{!sobs}" var="sob" >
    <apex:repeat value="{!columns}" var="c">
        <apex:column value="{!sob[c]}"/>
    </apex:repeat>
</apex:pageBlockTable>

PS

Here is a fairly complicated example of conditionally rendering different columns depending on the field name:

<apex:repeat var="f" value="{!fields}">
    <apex:column rendered="{! f == 'Name'}">
        <apex:facet name="header">Return To Work Name</apex:facet>
        <apex:outputLink value="/{!item.Id}?saveURL={!currentPageUrl}">
            {!item.Name}
        </apex:outputLink>
    </apex:column>
    <apex:column rendered="{! f != 'Id' && f != 'Name' && f != 'Attachments__c' && f != 'Earnings__c'
                && f != 'EarningsPerWeek__c' && f != 'EarningsPerMonth__c'}" value="{!item[f]}"/>
    <apex:column rendered="{! f == 'Earnings__c'}" value="{!item.Earnings__c}" headerClass="textalignright" styleClass="textalignright" />
    <apex:column rendered="{! f == 'EarningsPerWeek__c'}" value="{!item.EarningsPerWeek__c}" headerClass="textalignright" styleClass="textalignright"/>
    <apex:column rendered="{! f == 'EarningsPerMonth__c'}" value="{!item.EarningsPerMonth__c}" headerClass="textalignright" styleClass="textalignright"/>
    <apex:column rendered="{! f == 'Attachments__c'}" value="{!item.Attachments__c}" headerClass="textalignright" styleClass="textalignright"/>
</apex:repeat>