Extending the Content Search web part to display a "Show all" link

Question

I want to use the Content Search web part to display a site's latest news articles. Also, I need a "Show all" link to the bottom of the web part - this link would take the user to a search results page. The link text and URL must be customizable in the Web part properties.

What is the best way to go about this? I have found examples of extending the CSWP for the purpose of programmatically manipulating the search query, but I haven't found examples of how to change the output.

Answer 1

We found a solution allowing us to manipulate the Content Search web part in the following ways: 1) Append a "Show all" link to the web part's visual output 2) Add custom properties and use the values in code-behind.

First, we created a new (non-visual) web part extending ContentBySearchWebPart. Then we overrode CreateChildControls, adding our link control:

protected override void CreateChildControls()
{
    if (!string.IsNullOrEmpty(ShowAllUrl) && !string.IsNullOrEmpty(ShowAllText))
    {
        Link link = new Link();
        link.NavigateUrl = ShowAllUrl;
        link.Text = ShowAllText;
        link.CssClass = "ShowAll_Link";
        Controls.Add(link);
    }
    base.CreateChildControls();
}

Next, we add custom properties. First we declare our properties:

[System.Web.UI.WebControls.WebParts.WebBrowsable(true),
 System.Web.UI.WebControls.WebParts.WebDisplayName("Display text"),
 System.Web.UI.WebControls.WebParts.WebDescription(""),
 System.Web.UI.WebControls.WebParts.Personalizable(
 System.Web.UI.WebControls.WebParts.PersonalizationScope.Shared),
 System.ComponentModel.Category("Link to Show All"),
System.ComponentModel.DefaultValue("Show all")]
public string ShowAllText { get; set; }

[System.Web.UI.WebControls.WebParts.WebBrowsable(true),
System.Web.UI.WebControls.WebParts.WebDisplayName("URL"),
System.Web.UI.WebControls.WebParts.WebDescription(""),
System.Web.UI.WebControls.WebParts.Personalizable(
System.Web.UI.WebControls.WebParts.PersonalizationScope.Shared),
System.ComponentModel.Category("Link to Show All"),
System.ComponentModel.DefaultValue("")]
public string ShowAllUrl { get; set; }

Finally, we must override GetToolParts() in order to inject our custom properties into the settings panel:

public override ToolPart[] GetToolParts()
{
    List<ToolPart> tp = new List<ToolPart>(base.GetToolParts());
    tp.Add(new CustomPropertyToolPart());
    return tp.ToArray();
}

That's all there is to it. Here is the full class:

using Microsoft.Office.Server.Search.WebControls;
using Microsoft.SharePoint.Mobile.Controls;
using Microsoft.SharePoint.WebPartPages;

namespace Netcompany.FVS0001
{
    using System.Collections.Generic;

    public class CustomContentSearchWebPart : ContentBySearchWebPart
    {    
[System.Web.UI.WebControls.WebParts.WebBrowsable(true),
 System.Web.UI.WebControls.WebParts.WebDisplayName("Display text"),
 System.Web.UI.WebControls.WebParts.WebDescription(""),
 System.Web.UI.WebControls.WebParts.Personalizable(
 System.Web.UI.WebControls.WebParts.PersonalizationScope.Shared),
 System.ComponentModel.Category("Link to Show All"),
System.ComponentModel.DefaultValue("Show all")]
public string ShowAllText { get; set; }

[System.Web.UI.WebControls.WebParts.WebBrowsable(true),
System.Web.UI.WebControls.WebParts.WebDisplayName("URL"),
System.Web.UI.WebControls.WebParts.WebDescription(""),
System.Web.UI.WebControls.WebParts.Personalizable(
System.Web.UI.WebControls.WebParts.PersonalizationScope.Shared),
System.ComponentModel.Category("Link to Show All"),
System.ComponentModel.DefaultValue("")]
public string ShowAllUrl { get; set; }

        /// <summary>
        /// Override the creation of the settings panel, telling it to add our own custom properties from this class
        /// </summary>
        /// <returns></returns>
        public override ToolPart[] GetToolParts()
        {
            List<ToolPart> tp = new List<ToolPart>(base.GetToolParts());
            tp.Add(new CustomPropertyToolPart());
            return tp.ToArray();
        }

        /// <summary>
        /// Add a "Show all" link
        /// </summary>
        protected override void CreateChildControls()
        {
            if (!string.IsNullOrEmpty(ShowAllUrl) && !string.IsNullOrEmpty(ShowAllText))
            {
                Link link = new Link();
                link.NavigateUrl = ShowAllUrl;
                link.Text = ShowAllText;
                link.CssClass = "ShowAll_Link";
                Controls.Add(link);
            }
            base.CreateChildControls();
        }
    }
}