rerender attribute refreshing all columns in pageblocktable

Question

<apex:pageblockTable value="{!TasklstI}" var="tsk" id="table">
<apex:column rendered="{!if(ownerhide=false,true,false)}" headerValue="Assigned To"> <apex:commandLink value="{!tsk.owner.name}" action="{!editOwner}"  reRender="table"/></apex:column>
<apex:column rendered="{!if(ownerhide=true,true,false)}" headerValue="Assigned To"   > <apex:inputfield value="{!tsk.ownerId}"  /></apex:column>
</apex:pageblocktable>

public void editOwner(){
ownerhide = true;
}

But my requirement is when I click on hyperlink I need to get only 1 field to be editable. But here the entire column is in editable position. Am i missing anything.

I tried rerendering like this also But this is also not working

<apex:pageblockTable value="{!TasklstI}" var="tsk" >
    <apex:column rendered="{!if(ownerhide=false,true,false)}" headerValue="Assigned To"> <apex:commandLink value="{!tsk.owner.name}" action="{!editOwner}"  reRender="table"/></apex:column>
    <apex:column rendered="{!if(ownerhide=true,true,false)}" headerValue="Assigned To"  id="table" > <apex:inputfield value="{!tsk.ownerId}"  /></apex:column>
    </apex:pageblocktable>

Answer 1

The original problem is that the operations you've designed work on the entire column, not just a single cell. For example, the Boolean value ownerEdit is just a single value for all rows; there's no way for the code to know which row you meant. From your current design, I'd say the least amount of work would be to use a temporary record instead.

Controller Changes

Instead of having a Boolean value, we'll identify which row we're currently editing with a temporary task.

public Task ownerTask { get; set; }

In your constructor, remember to initialize the variable:

ownerTask = new Task();

We also need a way to edit the record, so we'll add an action method:

// The apex:commandLink populates this value to tell us which task to edit
public transient Id ownerEditId { get; set; }

public void ownerEdit() {
  ownerTask.Id = ownerEditId;
  // One-liner "find task by Id in a List" trick
  ownerTask.OwnerId = new Map<Id, Task>(TasklstI).get(ownerEditId).OwnerId;
}

We also need a way to update the task when we save:

public void saveEdit() {
  if(ownerTask.Id != null && ownerTask.OwnerId != null) {
    // This code assumes we'll save okay. Consider error handling here.
    update ownerTask;

    // Refresh ownership display value
    Task tempTask = [SELECT Owner.Name FROM Task WHERE Id = :ownerTask.Id];
    new Map<Id, Task>(TaskLstI).get(ownerTask.Id).Owner = tempTask.Owner;

    // end edit mode
    ownerTask.Id = null;
  }
}

And finally a cancel option:

public void cancelEdit() {
  ownerTask.Id = null;
}

Page Changes

Setting a rendered attribute at the apex:column level will affect all rows simultaneously. We only want to affect one row at a time, so we need to set the rendered attribute at the apex:commandLink/apex:inputField level.

<apex:pageblockTable value="{!TasklstI}" var="tsk" id="table">
  <apex:column headerValue="Assigned To">
    <apex:commandLink rendered="{!tsk.Id<>tempTask.Id}" value="{!tsk.owner.name}" action="{!ownerEdit}"  reRender="table">
      <apex:param assignTo="{!ownerEditId}" name="" value="{!tsk.Id}" />
    </apex:commandLink>
    <apex:inputfield value="{!ownerTask.ownerId}" rendered="{!tsk.Id=tempTask.Id}" />
  </apex:column>
</apex:pageblocktable>

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N.B. I didn't actually model this in my developer org, so there may be a few minor issues, but this should be very close to correct.