Hooks

A hook is an extension that is triggered in response to one, or more, system events. See Weavy.Core.Events for a list of available events.

Model

To add a hook that responds to an event you should first add a class that inherits from Hook. Your class should also implement the IHook<TEvent> interface for the event you want to handle. A good convention to follow is placing your class in the Models folder. In the example below we add a hook that listens to the AfterInsertComment event and trashes the inserted comment if it contains certain keywords.

using NLog;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Runtime.InteropServices;
using System.Threading.Tasks;
using Weavy.Core.Events;
using Weavy.Core.Models;
using Weavy.Core.Services;

namespace Weavy.Models {

    [Serializable]
    [Guid("CF2303B5-A8B1-4F91-8029-9F464338A8DC")]
    [Plugin(Description = "A hook that automatically trashes comments with certain keywords.")]
    public class CommentFilterHook : Hook, IHook<AfterInsertComment> {

        private static readonly Logger _log = LogManager.GetCurrentClassLogger();

        [Required]
        [DataType("Tags")]
        [Display(Name = "Keywords", Description = "A list of keywords to look for.")]
        public List<string> Keywords { get; set; }

        /// <summary>
        /// Trash comment if it contains one of the specified keywords.
        /// </summary>
        /// <param name="e"></param>
        public void Handle(AfterInsertComment e) {
            if (Keywords != null) {
                foreach (var keyword in Keywords) {
                    if (e.Inserted.Text.IndexOf(keyword, StringComparison.OrdinalIgnoreCase) >= 0) {
                        var trashed = CommentService.Trash(e.Inserted.Id);
                        _log.Warn($"Trashed comment '{trashed.Text}' with keyword '{keyword}'");
                        break;
                    }
                }
            }
        }
    }
}

Class attributes

As shown above, hooks must be decorated with the [Serializable] and [Guid] attributes.

To further customize your hook you can also decorate it with the[Plugin] attribute. Some of the properties you can set are:

• Icon – name of an icon to use when displaying the daemon.
• Color – the color to use for the icon.
• Name – display name for the content item, e.g. “Comment filter”.
• Description – a description to use for the daemon, e.g “A hook that automatically trashes comments with certain keywords.”.

Fields

Hook fields are pieces of information that can be added to a hook. This can be useful if your hook requires some kind of configuration or settings. Hook fields have a name and a type. In the example above, we added a field for storing the keywords not allowed in comments.

For a property to be considered a hook field, it must be declared as public read-write, i.e. the property has the public access modifier and have both a get and a set accessor.

Hook fields must also have one of the following supported types:

• enum
• byte
• short
• int
• long
• bool
• double
• float
• string
• Guid
• DateTime
• TimeSpan

Nullables and Lists of the above types are also supported, e.g. int?, List<string> and List<DateTime?>.

Field attributes

By decorating your fields with one, or more, of the following attributes you can customize how the field is displayed, edited and/or validated.

Datatype

By default, Weavy will look at the property type (in this case IList<string>) when deciding which editor to use for the field. By decorating a field with the [DataType] attribute you can specify an additional type to associate with the field. This value will then be used by the UI to determine which editor to use for the field.

[DataType("Tags")]
public List<string> Keywords { get; set; }

Here we specify that the Keywords field should use the Tags editor.

Display

The [Display] attribute lets you specify a name and description to use for the field.

[Display(Name = "Keywords", Description = "A list of keywords to look for.")]
public List<string> Keywords { get; set; }

Validation

By adding one, or more, [Validation] attributes to your fields you can control how they are validated.

[Required]
public List<string> Keywords { get; set; }

Here we specify that the Keywords property is required.

Configuration

If a hook requires some kind of configuration settings, like the Keywords property in our CommentFilterHook, you can navigate to /manage/hooks/XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX where the last segment should be replaced with the Guid of your Hook, in this case CF2303B5-A8B1-4F91-8029-9F464338A8DC for the CommentFilterHook.