HtmlAttribute.cs

using System.Collections.Generic;
using System.Text;
using System.Xml;
using Waher.Runtime.Collections;
 
namespace Waher.Content.Html
{
    public class HtmlAttribute : HtmlNode
    {
        private ChunkedList<HtmlNode> segments = null;
        private readonly string fullName;
        private readonly string localName;
        private readonly string prefix;
        private readonly bool hasPrefix;
        private string @value;
 
        public HtmlAttribute(HtmlDocument Document, HtmlElement Parent, int StartPosition,
            int EndPosition, string Name, string Value)
            : base(Document, Parent, StartPosition, EndPosition)
        {
            SplitName(Name, out this.prefix, out this.localName, out this.hasPrefix);
            this.fullName = Name;
            this.@value = Value;
            this.segments = null;
        }
 
        public HtmlAttribute(HtmlDocument Document, HtmlElement Parent, int StartPosition,
            int EndPosition, string Name)
            : base(Document, Parent, StartPosition, EndPosition)
        {
            SplitName(Name, out this.prefix, out this.localName, out this.hasPrefix);
            this.fullName = Name;
            this.@value = null;
            this.segments = null;
        }
 
        public HtmlAttribute(HtmlDocument Document, HtmlElement Parent, int StartPosition,
            string Name, string Value)
            : base(Document, Parent, StartPosition)
        {
            SplitName(Name, out this.prefix, out this.localName, out this.hasPrefix);
            this.fullName = Name;
            this.@value = Value;
            this.segments = null;
        }
 
        public HtmlAttribute(HtmlDocument Document, HtmlElement Parent, int StartPosition, string Name)
            : base(Document, Parent, StartPosition)
        {
            SplitName(Name, out this.prefix, out this.localName, out this.hasPrefix);
            this.fullName = Name;
            this.@value = null;
            this.segments = null;
        }
 
        public string FullName => this.fullName;
 
        public string LocalName => this.localName;
 
        public string Prefix => this.prefix;
 
        public bool HasPrefix => this.hasPrefix;
 
        internal void Add(HtmlNode Segment)
        {
            if (this.segments is null)
                this.segments = new ChunkedList<HtmlNode>();
 
            this.segments.Add(Segment);
            this.@value = null;
        }
 
        internal bool HasSegments => !(this.segments is null);
 
        public string Value
        {
            get
            {
                if (this.@value is null)
                {
                    if (!(this.segments is null))
                    {
                        StringBuilder sb = new StringBuilder();
 
                        foreach (HtmlNode N in this.segments)
                            sb.Append(N.ToString());
 
                        this.@value = sb.ToString();
                    }
                    else
                        this.@value = string.Empty;
                }
 
                return this.@value;
            }
 
            internal set
            {
                this.@value = value;
                this.segments = null;
            }
        }
 
        public override string ToString()
        {
            if (this.hasPrefix)
                return this.prefix + ":" + this.localName + "=" + this.Value;
            else
                return this.localName + "=" + this.Value;
        }
 
        public override void Export(XmlWriter Output, Dictionary<string, string> Namespaces)
        {
            if (this.hasPrefix)
            {
                if (Namespaces.TryGetValue(this.prefix, out string Namespace))
                    Output.WriteAttributeString(this.prefix, this.localName, Namespace, this.@value);
            }
            else
                Output.WriteAttributeString(this.localName, this.@value);
        }
 
        public override void Export(StringBuilder Output)
        {
            Output.Append(' ');
            Output.Append(this.fullName);
            Output.Append("=\"");
            Output.Append(Xml.XML.Encode(this.@value));
            Output.Append('"');
        }
    }
}