Separation of core library from the UWP app.
This commit is contained in:
Burak Kaan Köse
255
Wino.Core.Domain/Models/MailItem/HtmlPreviewVisitor.cs
Normal file
255
Wino.Core.Domain/Models/MailItem/HtmlPreviewVisitor.cs
Normal file
@@ -0,0 +1,255 @@
|
||||
using System;
|
||||
using System.Collections.Generic;
|
||||
using System.IO;
|
||||
using MimeKit;
|
||||
using MimeKit.Text;
|
||||
using MimeKit.Tnef;
|
||||
|
||||
namespace Wino.Core.Domain.Models.MailItem
|
||||
{
|
||||
/// <summary>
|
||||
/// Visits a MimeMessage and generates HTML suitable to be rendered by a browser control.
|
||||
/// </summary>
|
||||
public class HtmlPreviewVisitor : MimeVisitor
|
||||
{
|
||||
List<MultipartRelated> stack = new List<MultipartRelated>();
|
||||
List<MimeEntity> attachments = new List<MimeEntity>();
|
||||
|
||||
readonly string tempDir;
|
||||
|
||||
public string Body { get; set; }
|
||||
|
||||
/// <summary>
|
||||
/// Creates a new HtmlPreviewVisitor.
|
||||
/// </summary>
|
||||
/// <param name="tempDirectory">A temporary directory used for storing image files.</param>
|
||||
public HtmlPreviewVisitor(string tempDirectory)
|
||||
{
|
||||
tempDir = tempDirectory;
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// The list of attachments that were in the MimeMessage.
|
||||
/// </summary>
|
||||
public IList<MimeEntity> Attachments
|
||||
{
|
||||
get { return attachments; }
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// The HTML string that can be set on the BrowserControl.
|
||||
/// </summary>
|
||||
public string HtmlBody
|
||||
{
|
||||
get { return Body ?? string.Empty; }
|
||||
}
|
||||
|
||||
protected override void VisitMultipartAlternative(MultipartAlternative alternative)
|
||||
{
|
||||
// walk the multipart/alternative children backwards from greatest level of faithfulness to the least faithful
|
||||
for (int i = alternative.Count - 1; i >= 0 && Body == null; i--)
|
||||
alternative[i].Accept(this);
|
||||
}
|
||||
|
||||
protected override void VisitMultipartRelated(MultipartRelated related)
|
||||
{
|
||||
var root = related.Root;
|
||||
|
||||
// push this multipart/related onto our stack
|
||||
stack.Add(related);
|
||||
|
||||
// visit the root document
|
||||
root.Accept(this);
|
||||
|
||||
// pop this multipart/related off our stack
|
||||
stack.RemoveAt(stack.Count - 1);
|
||||
}
|
||||
|
||||
// look up the image based on the img src url within our multipart/related stack
|
||||
bool TryGetImage(string url, out MimePart image)
|
||||
{
|
||||
UriKind kind;
|
||||
int index;
|
||||
Uri uri;
|
||||
|
||||
if (Uri.IsWellFormedUriString(url, UriKind.Absolute))
|
||||
kind = UriKind.Absolute;
|
||||
else if (Uri.IsWellFormedUriString(url, UriKind.Relative))
|
||||
kind = UriKind.Relative;
|
||||
else
|
||||
kind = UriKind.RelativeOrAbsolute;
|
||||
|
||||
try
|
||||
{
|
||||
uri = new Uri(url, kind);
|
||||
}
|
||||
catch
|
||||
{
|
||||
image = null;
|
||||
return false;
|
||||
}
|
||||
|
||||
for (int i = stack.Count - 1; i >= 0; i--)
|
||||
{
|
||||
if ((index = stack[i].IndexOf(uri)) == -1)
|
||||
continue;
|
||||
|
||||
image = stack[i][index] as MimePart;
|
||||
return image != null;
|
||||
}
|
||||
|
||||
image = null;
|
||||
|
||||
return false;
|
||||
}
|
||||
|
||||
// Save the image to our temp directory and return a "file://" url suitable for
|
||||
// the browser control to load.
|
||||
// Note: if you'd rather embed the image data into the HTML, you can construct a
|
||||
// "data:" url instead.
|
||||
string SaveImage(MimePart image)
|
||||
{
|
||||
using (var memory = new MemoryStream())
|
||||
{
|
||||
image.Content.DecodeTo(memory);
|
||||
var buffer = memory.GetBuffer();
|
||||
var length = (int)memory.Length;
|
||||
var base64 = Convert.ToBase64String(buffer, 0, length);
|
||||
|
||||
return string.Format("data:{0};base64,{1}", image.ContentType.MimeType, base64);
|
||||
}
|
||||
|
||||
//string fileName = url
|
||||
// .Replace(':', '_')
|
||||
// .Replace('\\', '_')
|
||||
// .Replace('/', '_');
|
||||
|
||||
//string path = Path.Combine(tempDir, fileName);
|
||||
|
||||
//if (!File.Exists(path))
|
||||
//{
|
||||
// using (var output = File.Create(path))
|
||||
// image.Content.DecodeTo(output);
|
||||
//}
|
||||
|
||||
//return "file://" + path.Replace('\\', '/');
|
||||
}
|
||||
|
||||
// Replaces <img src=...> urls that refer to images embedded within the message with
|
||||
// "file://" urls that the browser control will actually be able to load.
|
||||
void HtmlTagCallback(HtmlTagContext ctx, HtmlWriter htmlWriter)
|
||||
{
|
||||
if (ctx.TagId == HtmlTagId.Image && !ctx.IsEndTag && stack.Count > 0)
|
||||
{
|
||||
ctx.WriteTag(htmlWriter, false);
|
||||
|
||||
// replace the src attribute with a file:// URL
|
||||
foreach (var attribute in ctx.Attributes)
|
||||
{
|
||||
if (attribute.Id == HtmlAttributeId.Src)
|
||||
{
|
||||
MimePart image;
|
||||
string url;
|
||||
|
||||
if (!TryGetImage(attribute.Value, out image))
|
||||
{
|
||||
htmlWriter.WriteAttribute(attribute);
|
||||
continue;
|
||||
}
|
||||
|
||||
url = SaveImage(image);
|
||||
|
||||
htmlWriter.WriteAttributeName(attribute.Name);
|
||||
htmlWriter.WriteAttributeValue(url);
|
||||
}
|
||||
else
|
||||
{
|
||||
htmlWriter.WriteAttribute(attribute);
|
||||
}
|
||||
}
|
||||
}
|
||||
else if (ctx.TagId == HtmlTagId.Body && !ctx.IsEndTag)
|
||||
{
|
||||
ctx.WriteTag(htmlWriter, false);
|
||||
|
||||
// add and/or replace oncontextmenu="return false;"
|
||||
foreach (var attribute in ctx.Attributes)
|
||||
{
|
||||
if (attribute.Name.ToLowerInvariant() == "oncontextmenu")
|
||||
continue;
|
||||
|
||||
htmlWriter.WriteAttribute(attribute);
|
||||
}
|
||||
|
||||
htmlWriter.WriteAttribute("oncontextmenu", "return false;");
|
||||
}
|
||||
else
|
||||
{
|
||||
if (ctx.TagId == HtmlTagId.Unknown)
|
||||
{
|
||||
ctx.DeleteTag = true;
|
||||
ctx.DeleteEndTag = true;
|
||||
}
|
||||
else
|
||||
{
|
||||
ctx.WriteTag(htmlWriter, true);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
protected override void VisitTextPart(TextPart entity)
|
||||
{
|
||||
TextConverter converter;
|
||||
|
||||
if (Body != null)
|
||||
{
|
||||
// since we've already found the body, treat this as an attachment
|
||||
attachments.Add(entity);
|
||||
return;
|
||||
}
|
||||
|
||||
if (entity.IsHtml)
|
||||
{
|
||||
converter = new HtmlToHtml
|
||||
{
|
||||
HtmlTagCallback = HtmlTagCallback
|
||||
};
|
||||
}
|
||||
else if (entity.IsFlowed)
|
||||
{
|
||||
var flowed = new FlowedToHtml();
|
||||
string delsp;
|
||||
|
||||
if (entity.ContentType.Parameters.TryGetValue("delsp", out delsp))
|
||||
flowed.DeleteSpace = delsp.ToLowerInvariant() == "yes";
|
||||
|
||||
converter = flowed;
|
||||
}
|
||||
else
|
||||
{
|
||||
converter = new TextToHtml();
|
||||
}
|
||||
|
||||
Body = converter.Convert(entity.Text);
|
||||
}
|
||||
|
||||
protected override void VisitTnefPart(TnefPart entity)
|
||||
{
|
||||
// extract any attachments in the MS-TNEF part
|
||||
attachments.AddRange(entity.ExtractAttachments());
|
||||
}
|
||||
|
||||
protected override void VisitMessagePart(MessagePart entity)
|
||||
{
|
||||
// treat message/rfc822 parts as attachments
|
||||
attachments.Add(entity);
|
||||
}
|
||||
|
||||
protected override void VisitMimePart(MimePart entity)
|
||||
{
|
||||
// realistically, if we've gotten this far, then we can treat this as an attachment
|
||||
// even if the IsAttachment property is false.
|
||||
attachments.Add(entity);
|
||||
}
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user