Create a custom HTX function

To create a custom HTX function you inherit the class HtxExtension and override the functions Execute and optionally ExecuteClose.

Execute and ExecuteClose is run on the same object, so it's safe to store values from Execute and use them in ExecuteClose.

The content parameter passed to ExecuteClose is the parsed content from between the opening and the closing tag.

The name of the function will be as defined in the HtxExtension-attribute placed on the class.

See this example from the <z:sendmail-function:

using System.Collections;
using System.IO;
using System.Net.Mail;
using System.Text;
using System.Web.Hosting;
using Zpider.eShop.Web.Base;
using Zpider.eShop.Web.Base.Plugins;
using Zpider.Sys.Lib.Convert;
using Zpider.Sys.Lib.Mail;
using Zpider.Sys.Lib.Messaging;
using Zpider.Sys.Lib.Template;
namespace Plugin.SendMail
{
    [HtxExtension(Name = "SendMail")]
    public class SendMailFunction : HtxExtension
    {
        public override bool IsClosingFunction => true;
        public string Subject { get; set; }
        public string To { get; set; }
        public string From { get; set; }
        public string FromName { get; private set; }
        public bool PlainText { get; set; }
        public string Attachments { get; set; }
        public string ReplyTo { get; set; }
        public override ProviderRetval Execute(IDictionary attributes, ScriptRunContext context)
        {
            Subject = attributes.Get<string>("subject");
            To = attributes.Get<string>("to") ?? Domain.Configuration.GeneralConfiguration.SenderEmail;
            From = attributes.Get<string>("from") ?? Domain.Configuration.GeneralConfiguration.SenderEmail;
            FromName = attributes.Get<string>("fromname") ?? Domain.Configuration.GeneralConfiguration.SenderName;
            PlainText = attributes.Get<bool>("plaintext");
            Attachments = attributes.Get<string>("attachments");
            ReplyTo = attributes.Get<string>("replyto");
            return ProviderRetval.ContinuePage;
        }
        public override void ExecuteClose(string content, ClosingTagItem item, ScriptRunContext runContext)
        {
            var generalConfiguration = Domain.Configuration.GeneralConfiguration;
            using (var message = new MailMessage
            {
                Subject = Subject,
                SubjectEncoding = Encoding.Default,
                Body = content,
                BodyEncoding = Encoding.Default
            })
            {
                AddRecipients(message);
                message.IsBodyHtml = !PlainText;
                message.From = !string.IsNullOrEmpty(From)
                    ? new MailAddress(From, FromName ?? From, Encoding.Default)
                    : new MailAddress(generalConfiguration.SenderEmail, generalConfiguration.SenderName);
                if (!string.IsNullOrEmpty(ReplyTo))
                {
                    var reply_to = ReplyTo.Split(split_list);
                    foreach (var s in reply_to)
                    {
                        if (!string.IsNullOrEmpty(s.Trim()))
                            message.ReplyToList.Add(s.Trim());
                    }
                }
                AddAttachmentsToMessage(message);
                IMessageBody messageBody = new MessageBody
                {
                    ["Message"] = new SerializableMailMessage(message)
                };
                Domain.eShopClient.SendMessage(messageBody, "Fusion.Mail", "SendMail", null);
            }
        }
        readonly char[] split_list = new[] { ',', ' ', ';' };
        private void AddRecipients(MailMessage message)
        {
            var to = To.Split(split_list);
            foreach (var s in to)
            {
                if (!string.IsNullOrEmpty(s.Trim()))
                    message.To.Add(s.Trim());
            }
        }
        private void AddAttachmentsToMessage(MailMessage message)
        {
            if (!string.IsNullOrEmpty(Attachments))
            {
                if (Attachments.IndexOf(';') > -1)
                {
                    foreach (var attachment in Attachments.Split(';'))
                    {
                        if (File.Exists(HostingEnvironment.MapPath(attachment)))
                        {
                            message.Attachments.Add(new Attachment(HostingEnvironment.MapPath(attachment)));
                        }
                        else if (File.Exists(attachment))
                        {
                            message.Attachments.Add(new Attachment(attachment));
                        }
                    }
                }
                else if (File.Exists(HostingEnvironment.MapPath(Attachments)))
                {
                    message.Attachments.Add(new Attachment(HostingEnvironment.MapPath(Attachments)));
                }
                else if (File.Exists(Attachments))
                {
                    message.Attachments.Add(new Attachment(Attachments));
                }
                else // Try to fetch the file from fusion
                {
                    var file = Utility.GetFile(FileServerType.Config, Attachments);
                    if (!string.IsNullOrEmpty(file) &&
                        File.Exists(HostingEnvironment.MapPath(file)))
                    {
                        message.Attachments.Add(new Attachment(file));
                    }
                }
            }
        }
    }
}

In addition you'll need a class inheriting from ZpiderPlugin to let Zpider know that there's a plugin in the DLL that needs to be loaded, and you'll need a description.json that tells Zpider what to load.

SendMailPlugin.cs:

using Zpider.eShop.Web.Base.Plugins;
namespace Plugin.SendMail
{
    /// In this case it can just be empty
    public class SendMailPlugin : ZpiderPlugin
    {
    }
}

description.json:

{
  "Name": "SendMail",
  "ShortName": "SendMail",
  "Description": "HTX addon to send mail using <z:sendmail in HTX code.",
  "Assembly": "Plugin.SendMail.dll"
}

Wrap it in a folder and place it in the Plugins folder in Zpider. It should then show up in the plugin administration in the new admin after a restart.

The folder structure should look like this

ZpiderRootFolder
 - Plugins
    - Plugin.SendMail
        - description.json
        - Plugin.SendMail.dll