Sometimes you want to show certain features only to certain people or people with a certain role. Let's add a standard Add button to the bottom of the grid that only shows up for people who are authorized with "Edit" rights to our block.

Step 1 - Check the user's authorization

Use the IsUserAuthorized() method by passing it the name of an action. That method returns true if the person viewing the block is authorized for that action. When true, we'll set the grid's Action bar to show the Add button.

Add the using Rock.Security; in the top section of your block to get access to the Authorization class and add the authorization check to the OnInit method like this:

using Rock.Security;
// ...
protected override void OnInit( EventArgs e )
{
    base.OnInit( e );
    
    if ( IsUserAuthorized( Authorization.EDIT ) )
    {
        gPeople.Actions.ShowAdd = true;
    }
    
    // ...

var currentPage = Rock.Web.Cache.PageCache.Read( RockPage.PageId );
currentPage.IsAuthorized( Authorization.EDIT, CurrentPerson );

Step 2 - Handle the button click

Let's wrap this up by handling the click action for your new Add button. We'll register a click handler called gPeople_Addin the OnInit() method and then create the handler method in the appropriate code region.

protected override void OnInit( EventArgs e )
{
    base.OnInit( e );

    if ( IsUserAuthorized( Authorization.EDIT ) )
    {
        gPeople.Actions.ShowAdd = true;
        gPeople.Actions.AddClick += gPeople_Add;
    }
    
    // ...
    
}

protected void gPeople_Add( object sender, EventArgs e )
{
    Response.Redirect( "~/NewFamily/" );
    
    // prevents .NET from quietly throwing ThreadAbortException
    Context.ApplicationInstance.CompleteRequest();
    return;
}

Once again, we can rely on a built-in named route used for adding new people/families.

Step 3 - Code cleanup

For best practice sake, let's move our grid data binding code into it's own method called BindGrid(). This will set us up for one more little improvement we'll cover in the next step.

protected override void OnLoad( EventArgs e )
{
    base.OnLoad( e );

    if ( !Page.IsPostBack )
    {
        BindGrid();
    }
}

// ...

protected void BindGrid()
{
    var genderValue = GetAttributeValue( "GenderFilter" );

    var query = new PersonService( new RockContext() ).Queryable();

    if ( !string.IsNullOrEmpty( genderValue ) )
    {
        Gender gender = genderValue.ConvertToEnum<Gender>();
        query = query.Where( p => p.Gender == gender );
    }

    gPeople.DataSource = query.ToList();
    gPeople.DataBind();
}

Step 4 - That little improvement

Have you noticed that you've had to reload the page after you change a block property in order to see it take effect? Let's fix that so the grid refreshes immediately when the property changes.

The Stark block you started with comes with the necessary event handlers that allows you do something when the block's properties change. You may have even seen those extra lines in the OnInit method and an empty Block_BlockUpdated() code block. This Block_BlockUpdated() method is being called but it won't do anything until you add some appropriate code.

Now that we moved our data binding code to its own BindGrid() method, we can call it in Block_BlockUpdated() like this:.

protected void Block_BlockUpdated( object sender, EventArgs e )
{
    BindGrid();
}

Now go and change the gender setting and watch the magic.

Here is the final, complete code:

using System;
using System.ComponentModel;
using System.IO;
using System.Linq;
using System.Web.UI;
using System.Web.UI.WebControls;

using Rock;
using Rock.Data;
using Rock.Model;
using Rock.Web.Cache;
using Rock.Web.UI.Controls;
using Rock.Attribute;
using Rock.Security;

namespace RockWeb.Plugins.org_rocksolidchurch.Tutorials
{
    /// <summary>
    /// Template block for developers to use to start a new block.
    /// </summary>
    [DisplayName( "Hello World Fetching Data" )]
    [Category( "rocksolidchurch > Tutorials" )]
    [Description( "A simple block to fetch some data from Rock." )]

    [CustomRadioListField( "Gender Filter", "Select in order to list only records for that gender",
         "1^Male,2^Female", required: false )]
    [LinkedPage( "Related Page" )]
    public partial class HelloWorldFetchingData : Rock.Web.UI.RockBlock
    {
        protected override void OnInit( EventArgs e )
        {
            base.OnInit( e );

            if ( IsUserAuthorized( Authorization.EDIT ) )
            {
                gPeople.Actions.ShowAdd = true;
                gPeople.Actions.AddClick += gPeople_Add;
            }

            // This event gets fired after block settings are updated.
            this.BlockUpdated += Block_BlockUpdated;
            this.AddConfigurationUpdateTrigger( upnlContent );
        }

        protected override void OnLoad( EventArgs e )
        {
            base.OnLoad( e );

            if ( !Page.IsPostBack )
            {
                BindGrid();
            }
        }

        protected void Block_BlockUpdated( object sender, EventArgs e )
        {
            BindGrid();
        }

        protected void gPeople_Add( object sender, EventArgs e )
        {
            Response.Redirect( "~/NewFamily/" );
            
            // prevents .NET from quietly throwing ThreadAbortException
            Context.ApplicationInstance.CompleteRequest();
            return;
        }

        protected void gPeople_RowSelected( object sender, RowEventArgs e )
        {
            NavigateToLinkedPage( "RelatedPage", "PersonId", (int)e.RowKeyValues["Id"] );
        }

        protected void BindGrid()
        {
            var genderValue = GetAttributeValue( "GenderFilter" );

            var query = new PersonService( new RockContext() ).Queryable();

            if ( !string.IsNullOrEmpty( genderValue ) )
            {
                Gender gender = genderValue.ConvertToEnum<Gender>();
                query = query.Where( p => p.Gender == gender );
            }

            gPeople.DataSource = query.ToList();
            gPeople.DataBind();
        }
    }
}