Merge pull request #36 from dotnet-campus/t/lindexi/Update

更新 9 月版

Author: lindexi

src/DocumentFormat.OpenXml.Flatten/DocumentFormat.OpenXml.Flatten/Compatibilities/Packaging/CompatiblePackage.cs

@@ -0,0 +1,23 @@
+using System.IO;
+using System.IO.Packaging;
+
+namespace DocumentFormat.OpenXml.Flatten.Compatibilities.Packaging;
+
+/// <summary>
+/// 带兼容处理的 Package 提供器
+/// </summary>
+public static class CompatiblePackageProvider
+{
+    /// <summary>
+    /// 从传入的 <paramref name="s"/> 打开 <see cref="CompatiblePackage"/> 对象
+    /// </summary>
+    /// <param name="s"></param>
+    /// <param name="packageFileMode"></param>
+    /// <param name="packageFileAccess"></param>
+    /// <returns></returns>
+    public static Package OpenPackage(Stream s, FileMode packageFileMode,
+        FileAccess packageFileAccess)
+    {
+        return CompatiblePackage.OpenPackage(s, packageFileMode, packageFileAccess);
+    }
+}

src/DocumentFormat.OpenXml.Flatten/DocumentFormat.OpenXml.Flatten/Compatibilities/Packaging/CompatiblePackageProvider.cs

@@ -0,0 +1,117 @@
+using System;
+using System.IO;
+using System.IO.Packaging;
+using System.Text.RegularExpressions;
+
+namespace DocumentFormat.OpenXml.Flatten.Compatibilities.Packaging;
+
+partial class CompatiblePackage
+{
+    private class EmptyPackagePart : PackagePart
+    {
+        private Package _package;
+        private readonly ContentTypeHelper _contentTypeHelper;
+        public EmptyPackagePart(Package package, Uri partUri, ContentTypeHelper contentTypeHelper) : base(package, partUri)
+        {
+            _package = package;
+            _contentTypeHelper = contentTypeHelper;
+        }
+
+        protected override string GetContentTypeCore()
+        {
+            const string UnknownType = "application/vnd.openxmlformats-officedocument.miss-content-unknown-type";
+
+            var validatedPartUri = PackUriHelper.GetRelationshipPartUri(Uri) as PackUriHelper.ValidatedPartUri;
+            if (validatedPartUri == null)
+            {
+                return UnknownType;
+            }
+
+            var sourcePartUriFromRelationshipPartUri = PackUriHelper.GetSourcePartUriFromRelationshipPartUri(validatedPartUri) as PackUriHelper.ValidatedPartUri;
+            if (sourcePartUriFromRelationshipPartUri is not null)
+            {
+                var contentType = GetContentType(sourcePartUriFromRelationshipPartUri);
+                if (!string.IsNullOrEmpty(contentType?.ToString()))
+                {
+                    return contentType!.ToString();
+                }
+            }
+            return UnknownType;
+        }
+
+        internal CompatiblePackage.ContentType? GetContentType(CompatiblePackage.PackUriHelper.ValidatedPartUri partUri)
+        {
+            //Step 1: Check if there is an override entry present corresponding to the
+            //partUri provided. Override takes precedence over the default entries
+            var overrideDictionary = _contentTypeHelper.GetOverrideDictionary();
+            if (overrideDictionary != null)
+            {
+                if (overrideDictionary.ContainsKey(partUri))
+                    return overrideDictionary[partUri];
+            }
+
+            //Step 2: 通过路径进行特殊判断
+            // 例如 Slide 几的页面路径
+            var uri = partUri.OriginalString;
+            if (Regex.IsMatch(uri, @"/ppt/slides/slide\d+.xml"))
+            {
+                // "/ppt/slides/slide0.xml"
+                return new CompatiblePackage.ContentType(
+                    "application/vnd.openxmlformats-officedocument.presentationml.slide+xml");
+            }
+
+            if (Regex.IsMatch(uri, @"/ppt/slideLayouts/slideLayout\d+\.xml"))
+            {
+                // "/ppt/slideLayouts/slideLayout0.xml"
+                return new CompatiblePackage.ContentType("application/vnd.openxmlformats-officedocument.presentationml.slideLayout+xml");
+            }
+
+            if (Regex.IsMatch(uri, @"/ppt/slideMasters/slideMaster\d\.xml"))
+            {
+                // "/ppt/slideMasters/slideMaster0.xml"
+                return new CompatiblePackage.ContentType("application/vnd.openxmlformats-officedocument.presentationml.slideMaster+xml");
+            }
+
+            if (Regex.IsMatch(uri, @"/ppt/theme/theme\d+\.xml"))
+            {
+                // "/ppt/theme/theme0.xml"
+                return new CompatiblePackage.ContentType("application/vnd.openxmlformats-officedocument.theme+xml");
+            }
+
+            if (Regex.IsMatch(uri, @"/ppt/notesMasters/notesMaster\d+\.xml"))
+            {
+                // "/ppt/notesMasters/notesMaster0.xml"
+                return new CompatiblePackage.ContentType("application/vnd.openxmlformats-officedocument.presentationml.notesMaster+xml");
+            }
+
+            //Step 3: Check if there is a default entry corresponding to the
+            //extension of the partUri provided.
+            string extension = partUri.PartUriExtension;
+
+            var defaultDictionary = _contentTypeHelper.GetDefaultDictionary();
+            if (defaultDictionary.ContainsKey(extension))
+                return defaultDictionary[extension];
+
+            //Step 4: 使用后缀名默认
+            extension = extension.ToLowerInvariant();
+            var extensionToContentType = ExtensionToContentType(extension);
+            if (extensionToContentType != null)
+            {
+                return new CompatiblePackage.ContentType(extensionToContentType);
+            }
+
+            //Step 5: If we did not find an entry in the override and the default
+            //dictionaries, this is an error condition
+            return null;
+        }
+
+        protected override Stream GetStreamCore(FileMode mode, FileAccess access)
+        {
+            var memoryStream = new MemoryStream();
+            return memoryStream;
+        }
+
+        private static string? ExtensionToContentType(string extensionWithLowerInvariant)
+            => MimeUtility.LookupType(extensionWithLowerInvariant);
+    }
+}