NopCommerce源码架构详解--插件机制相关源码分析二

上一篇文章介绍了一下NopCommerce插件机制相关所有到一些核心类的主要功能和作用。现在我们就来看看这些类具体是怎么实现的。

nop.Core.Plugins.PluginDescriptor

我们还是先来看看类PluginDescriptor相关的类图：

PluginDescriptor实现接口IPlugin和IComparable，其源码如下：

1. using System;
2. using System.Collections.Generic;
3. using System.IO;
4. using System.Reflection;
5. using Nop.Core.Infrastructure;
6.  
7. namespace Nop.Core.Plugins
8. {
9. public class PluginDescriptor : IComparable
10. {
11. public PluginDescriptor()
12. {
13. this.SupportedVersions = new List();
14. this.LimitedToStores = new List();
15. }
16.  
17.  
18. public PluginDescriptor(Assembly referencedAssembly, FileInfo originalAssemblyFile,
19. Type pluginType)
20. : this()
21. {
22. this.ReferencedAssembly = referencedAssembly;
23. this.OriginalAssemblyFile = originalAssemblyFile;
24. this.PluginType = pluginType;
25. }
26. ///
27. /// 插件的文件名
28. ///
29. public virtual string PluginFileName { get; set; }
30.  
31. ///
32. /// 插件的type类型
33. ///
34. public virtual Type PluginType { get; set; }
35.  
36. ///
37. /// The assembly that has been shadow copied that is active in the application
38. ///
39. public virtual Assembly ReferencedAssembly { get; internal set; }
40.  
41. ///
42. /// The original assembly file that a shadow copy was made from it
43. ///
44. public virtual FileInfo OriginalAssemblyFile { get; internal set; }
45.  
46. ///
47. /// Gets or sets the plugin group
48. ///
49. public virtual string Group { get; set; }
50.  
51. ///
52. /// Gets or sets the friendly name
53. ///
54. public virtual string FriendlyName { get; set; }
55.  
56. ///
57. /// Gets or sets the system name
58. ///
59. public virtual string SystemName { get; set; }
60.  
61. ///
62. /// 插件版本
63. ///
64. public virtual string Version { get; set; }
65.  
66. ///
67. /// 插件所支持版本列表
68. ///
69. public virtual IList SupportedVersions { get; set; }
70.  
71. ///
72. /// 作者
73. ///
74. public virtual string Author { get; set; }
75.  
76. ///
77. /// Gets or sets the display order
78. ///
79. public virtual int DisplayOrder { get; set; }
80.  
81. ///
82. /// 插件所支持店铺列表.如果为空标示该插件在所有店铺中可用。
83. ///
84. public virtual IList LimitedToStores { get; set; }
85.  
86. ///
87. /// Gets or sets the value indicating whether plugin is installed
88. ///
89. public virtual bool Installed { get; set; }
90.  
91. //获取插件实例对象
92. public virtual T Instance() where T : class, IPlugin
93. {
94. object instance;
95. //通过IoC容器获取插件类型的实例对象
96. if (!EngineContext.Current.ContainerManager.TryResolve(PluginType, null, out instance))
97. {
98. //not resolved
99. instance = EngineContext.Current.ContainerManager.ResolveUnregistered(PluginType);
100. }
101. var typedInstance = instance as T;
102. if (typedInstance != null)
103. typedInstance.PluginDescriptor = this;
104. return typedInstance;
105. }
106.  
107. public IPlugin Instance()
108. {
109. return Instance();
110. }
111.  
112. public int CompareTo(PluginDescriptor other)
113. { //实现CompareTo方法是为了以后插件排序
114. if (DisplayOrder != other.DisplayOrder)
115. return DisplayOrder.CompareTo(other.DisplayOrder);
116. else
117. return FriendlyName.CompareTo(other.FriendlyName);
118. }
119.  
120. public override string ToString()
121. {
122. return FriendlyName;
123. }
124.  
125. public override bool Equals(object obj)
126. {
127. var other = obj as PluginDescriptor;
128. return other != null &&
129. SystemName != null &&
130. SystemName.Equals(other.SystemName);
131. }
132.  
133. public override int GetHashCode()
134. {
135. return SystemName.GetHashCode();
136. }
137. }
138. }

PluginDescriptor封装了插件描述相关的信息及一些插件相关的操作。

Nop.Core.Plugins.PluginFinder

 

1. using System;
2. using System.Collections.Generic;
3. using System.linq;
4.  
5. namespace Nop.Core.Plugins
6. {
7. ///
8. /// Plugin finder
9. ///
10. public class PluginFinder : IPluginFinder
11. {
12. #region Fields
13.  
14. private IList _plugins;
15.  
16. private bool _arePluginsLoaded = false;
17.  
18. #endregion
19.  
20. #region Utilities
21.  
22. ///
23. /// 确保插件被加载
24. ///
25. protected virtual void EnsurePluginsAreLoaded()
26. {
27. if (!_arePluginsLoaded)
28. {
29. var foundPlugins = PluginManager.ReferencedPlugins.ToList();
30. foundPlugins.Sort(); //sort
31. _plugins = foundPlugins.ToList();
32.  
33. _arePluginsLoaded = true;
34. }
35. }
36.  
37. #endregion
38.  
39. #region Methods
40.  
41. ///
42. /// 检查插件是否在在指定店铺中可用
43. ///
44. /// Plugin descriptor to check
45. /// Store identifier to check
46. /// true - available; false - no
47. public virtual bool AuthenticateStore(PluginDescriptor pluginDescriptor, int storeId)
48. {
49. if (pluginDescriptor == null)
50. throw new ArgumentNullException("pluginDescriptor");
51.  
52. //no validation required
53. if (storeId == 0)
54. return true;
55.  
56. if (pluginDescriptor.LimitedToStores.Count == 0)
57. return true;
58.  
59. return pluginDescriptor.LimitedToStores.Contains(storeId);
60. }
61.  
62. ///
63. /// 获取指定类型的插件集合
64. ///
65. /// The type of plugins to get.
66. /// A value indicating whether to load only installed plugins
67. /// Load records allowed only in a specified store; pass 0 to load all records
68. /// Plugins
69. public virtual IEnumerable GetPlugins(bool installedOnly = true, int storeId = 0) where T : class, IPlugin
70. {
71. EnsurePluginsAreLoaded();
72.  
73. foreach (var plugin in _plugins)
74. if (typeof(T).IsAssignableFrom(plugin.PluginType))
75. if (!installedOnly || plugin.Installed)
76. if (AuthenticateStore(plugin, storeId))
77. yield return plugin.Instance();
78. }
79.  
80. ///
81. /// 获取插件描述descriptors--泛型方法
82. ///
83. /// A value indicating whether to load only installed plugins
84. /// Load records allowed only in a specified store; pass 0 to load all records
85. /// Plugin descriptors
86. public virtual IEnumerable GetPluginDescriptors(bool installedOnly = true, int storeId = 0)
87. {
88. EnsurePluginsAreLoaded();
89.  
90. foreach (var plugin in _plugins)
91. if (!installedOnly || plugin.Installed)
92. if (AuthenticateStore(plugin, storeId))
93. yield return plugin;
94. }
95.  
96. ///
97. /// 获取指定类型的插件描述descriptors--泛型方法
98. ///
99. /// The type of plugin to get.
100. /// A value indicating whether to load only installed plugins
101. /// Load records allowed only in a specified store; pass 0 to load all records
102. /// Plugin descriptors
103. public virtual IEnumerable GetPluginDescriptors(bool installedOnly = true, int storeId = 0)
104. where T : class, IPlugin
105. {
106. EnsurePluginsAreLoaded();
107.  
108. foreach (var plugin in _plugins)
109. if (typeof(T).IsAssignableFrom(plugin.PluginType))
110. if (!installedOnly || plugin.Installed)
111. if (AuthenticateStore(plugin, storeId))
112. yield return plugin;
113. }
114.  
115. ///
116. /// 通过插件的系统名字获取插件
117. ///
118. /// Plugin system name
119. /// A value indicating whether to load only installed plugins
120. /// >Plugin descriptor
121. public virtual PluginDescriptor GetPluginDescriptorBySystemName(string systemName, bool installedOnly = true)
122. {
123. return GetPluginDescriptors(installedOnly)
124. .SingleOrDefault(p => p.SystemName.Equals(systemName, StringComparison.InvariantCultureIgnoreCase));
125. }
126.  
127. ///
128. /// 通过插件的系统名字获取插件--泛型方法
129. ///
130. /// The type of plugin to get.
131. /// Plugin system name
132. /// A value indicating whether to load only installed plugins
133. /// >Plugin descriptor
134. public virtual PluginDescriptor GetPluginDescriptorBySystemName(string systemName, bool installedOnly = true) where T : class, IPlugin
135. {
136. return GetPluginDescriptors(installedOnly)
137. .SingleOrDefault(p => p.SystemName.Equals(systemName, StringComparison.InvariantCultureIgnoreCase));
138. }
139.  
140. ///
141. /// 重新加载插件
142. ///
143. public virtual void ReloadPlugins()
144. {
145. _arePluginsLoaded = false;
146. EnsurePluginsAreLoaded();
147. }
148.  
149. #endregion
150. }
151. }

PluginFinder起到一个插件查找器的作用，这和我之前写的文章ITypeFinder有点类似。NopCommerce源码架构详解--TypeFinder程序集类型自动查找及操作相关源码分析

Nop.Core.Plugins.PluginManager

 

虽然PluginFinder源码有点长，但是我还是要放出来看看它是如何实现的：

1. using System;
2. using System.Collections.Generic;
3. using System.Configuration;
4. using System.Diagnostics;
5. using System.IO;
6. using System.Linq;
7. using System.Reflection;
8. using System.Threading;
9. using System.Web;
10. using System.Web.Compilation;
11. using System.Web.Hosting;
12. using Nop.Core.ComponentModel;
13. using Nop.Core.Plugins;
14. //Application开始运行前就运行这个类PluginManager的方法Initialize
15. [assembly: PreApplicationStartMethod(typeof(PluginManager), "Initialize")]
16. namespace Nop.Core.Plugins
17. {
18. ///
19. /// Sets the application up for the plugin referencing
20. ///
21. public class PluginManager
22. {
23. #region Const
24. //已安装插件列表记录文件位置
25. private const string InstalledPluginsFilePath = "~/App_Data/InstalledPlugins.txt";
26. //插件目录位置
27. private const string PluginsPath = "~/Plugins";
28. private const string ShadowCopyPath = "~/Plugins/bin";
29.  
30. #endregion
31.  
32. #region Fields
33.  
34. private static readonly ReaderWriterLockSlim Locker = new ReaderWriterLockSlim();
35. private static DirectoryInfo _shadowCopyFolder;
36. private static bool _clearShadowDirectoryOnStartup;
37.  
38. #endregion
39.  
40. #region Methods
41.  
42. ///
43. /// Returns a collection of all referenced plugin assemblies that have been shadow copied
44. ///
45. public static IEnumerable ReferencedPlugins { get; set; }
46.  
47. ///
48. /// Returns a collection of all plugin which are not compatible with the current version
49. ///
50. public static IEnumerable IncompatiblePlugins { get; set; }
51.  
52. ///
53. /// 初始化
54. ///
55. public static void Initialize()
56. {
57. using (new WriteLockDisposable(Locker))
58. {
59. // TODO: Add verbose exception handling / raising here since this is happening on app startup and could
60. // prevent app from starting altogether
61. var pluginFolder = new DirectoryInfo(HostingEnvironment.MapPath(PluginsPath));
62. _shadowCopyFolder = new DirectoryInfo(HostingEnvironment.MapPath(ShadowCopyPath));
63.  
64. var referencedPlugins = new List();
65. var incompatiblePlugins = new List();
66.  
67. _clearShadowDirectoryOnStartup = !String.IsNullOrEmpty(ConfigurationManager.AppSettings["ClearPluginsShadowDirectoryOnStartup"]) &&
68. Convert.ToBoolean(ConfigurationManager.AppSettings["ClearPluginsShadowDirectoryOnStartup"]);
69.  
70. try
71. {
72. var installedPluginSystemNames = PluginFileParser.ParseInstalledPluginsFile(GetInstalledPluginsFilePath());
73. Directory.CreateDirectory(pluginFolder.FullName);
74. Directory.CreateDirectory(_shadowCopyFolder.FullName);
75.  
76. //get list of all files in bin
77. var binFiles = _shadowCopyFolder.GetFiles("*", SearchOption.AllDirectories);
78. if (_clearShadowDirectoryOnStartup)
79. {
80. //clear out shadow copied plugins
81. foreach (var f in binFiles)
82. {
83. try
84. {
85. File.Delete(f.FullName);
86. }
87. catch (Exception exc)
88. {
89. Debug.WriteLine("Error deleting file " + f.Name + ". Exception: " + exc);
90. }
91. }
92. }
93.  
94. //加载描述文件
95. foreach (var dfd in GetDescriptionFilesAndDescriptors(pluginFolder))
96. {
97. var descriptionFile = dfd.Key;
98. var pluginDescriptor = dfd.Value;
99.  
100. //ensure that version of plugin is valid
101. if (!pluginDescriptor.SupportedVersions.Contains(NopVersion.CurrentVersion, StringComparer.InvariantCultureIgnoreCase))
102. {
103. incompatiblePlugins.Add(pluginDescriptor.SystemName);
104. continue;
105. }
106.  
107. //some validation
108. if (String.IsNullOrWhiteSpace(pluginDescriptor.SystemName))
109. throw new Exception(string.Format("A plugin '{0}' has no system name. Try assigning the plugin a unique name and recompiling.", descriptionFile.FullName));
110. if (referencedPlugins.Contains(pluginDescriptor))
111. throw new Exception(string.Format("A plugin with '{0}' system name is already defined", pluginDescriptor.SystemName));
112.  
113. //set 'Installed' property
114. pluginDescriptor.Installed = installedPluginSystemNames
115. .FirstOrDefault(x => x.Equals(pluginDescriptor.SystemName, StringComparison.InvariantCultureIgnoreCase)) != null;
116.  
117. try
118. {
119. if (descriptionFile.Directory == null)
120. throw new Exception(string.Format("Directory cannot be resolved for '{0}' description file", descriptionFile.Name));
121. //get list of all DLLs in plugins (not in bin!)
122. var pluginFiles = descriptionFile.Directory.GetFiles("*.dll", SearchOption.AllDirectories)
123. //just make sure we're not registering shadow copied plugins
124. .Where(x => !binFiles.Select(q => q.FullName).Contains(x.FullName))
125. .Where(x => IsPackagePluginFolder(x.Directory))
126. .ToList();
127.  
128. //other plugin description info
129. var mainPluginFile = pluginFiles
130. .FirstOrDefault(x => x.Name.Equals(pluginDescriptor.PluginFileName, StringComparison.InvariantCultureIgnoreCase));
131. pluginDescriptor.OriginalAssemblyFile = mainPluginFile;
132.  
133. //shadow copy main plugin file
134. pluginDescriptor.ReferencedAssembly = PerformFileDeploy(mainPluginFile);
135.  
136. //load all other referenced assemblies now
137. foreach (var plugin in pluginFiles
138. .Where(x => !x.Name.Equals(mainPluginFile.Name, StringComparison.InvariantCultureIgnoreCase))
139. .Where(x => !IsAlreadyLoaded(x)))
140. PerformFileDeploy(plugin);
141.  
142. //init plugin type (only one plugin per assembly is allowed)
143. foreach (var t in pluginDescriptor.ReferencedAssembly.GetTypes())
144. if (typeof(IPlugin).IsAssignableFrom(t))
145. if (!t.IsInterface)
146. if (t.IsClass && !t.IsAbstract)
147. {
148. pluginDescriptor.PluginType = t;
149. break;
150. }
151.  
152. referencedPlugins.Add(pluginDescriptor);
153. }
154. catch (ReflectionTypeLoadException ex)
155. {
156. var msg = string.Empty;
157. foreach (var e in ex.LoaderExceptions)
158. msg += e.Message + Environment.NewLine;
159.  
160. var fail = new Exception(msg, ex);
161. Debug.WriteLine(fail.Message, fail);
162.  
163. throw fail;
164. }
165. }
166. }
167. catch (Exception ex)
168. {
169. var msg = string.Empty;
170. for (var e = ex; e != null; e = e.InnerException)
171. msg += e.Message + Environment.NewLine;
172.  
173. var fail = new Exception(msg, ex);
174. Debug.WriteLine(fail.Message, fail);
175.  
176. throw fail;
177. }
178.  
179. ReferencedPlugins = referencedPlugins;
180. IncompatiblePlugins = incompatiblePlugins;
181.  
182. }
183. }
184.  
185. ///
186. /// Mark plugin as installed
187. ///
188. /// Plugin system name
189. public static void MarkPluginAsInstalled(string systemName)
190. {
191. if (String.IsNullOrEmpty(systemName))
192. throw new ArgumentNullException("systemName");
193.  
194. var filePath = HostingEnvironment.MapPath(InstalledPluginsFilePath);
195. if (!File.Exists(filePath))
196. using (File.Create(filePath))
197. {
198. //we use 'using' to close the file after it's created
199. }
200.  
201.  
202. var installedPluginSystemNames = PluginFileParser.ParseInstalledPluginsFile(GetInstalledPluginsFilePath());
203. bool alreadyMarkedAsInstalled = installedPluginSystemNames
204. .FirstOrDefault(x => x.Equals(systemName, StringComparison.InvariantCultureIgnoreCase)) != null;
205. if (!alreadyMarkedAsInstalled)
206. installedPluginSystemNames.Add(systemName);
207. PluginFileParser.SaveInstalledPluginsFile(installedPluginSystemNames,filePath);
208. }
209.  
210. ///
211. /// Mark plugin as uninstalled
212. ///
213. /// Plugin system name
214. public static void MarkPluginAsUninstalled(string systemName)
215. {
216. if (String.IsNullOrEmpty(systemName))
217. throw new ArgumentNullException("systemName");
218.  
219. var filePath = HostingEnvironment.MapPath(InstalledPluginsFilePath);
220. if (!File.Exists(filePath))
221. using (File.Create(filePath))
222. {
223. //we use 'using' to close the file after it's created
224. }
225.  
226.  
227. var installedPluginSystemNames = PluginFileParser.ParseInstalledPluginsFile(GetInstalledPluginsFilePath());
228. bool alreadyMarkedAsInstalled = installedPluginSystemNames
229. .FirstOrDefault(x => x.Equals(systemName, StringComparison.InvariantCultureIgnoreCase)) != null;
230. if (alreadyMarkedAsInstalled)
231. installedPluginSystemNames.Remove(systemName);
232. PluginFileParser.SaveInstalledPluginsFile(installedPluginSystemNames,filePath);
233. }
234.  
235. ///
236. /// Mark plugin as uninstalled
237. ///
238. public static void MarkAllPluginsAsUninstalled()
239. {
240. var filePath = HostingEnvironment.MapPath(InstalledPluginsFilePath);
241. if (File.Exists(filePath))
242. File.Delete(filePath);
243. }
244.  
245. #endregion
246.  
247. #region Utilities
248.  
249. ///
250. /// Get description files
251. ///
252. /// Plugin direcotry info
253. /// Original and parsed description files
254. private static IEnumerable> GetDescriptionFilesAndDescriptors(DirectoryInfo pluginFolder)
255. {
256. if (pluginFolder == null)
257. throw new ArgumentNullException("pluginFolder");
258.  
259. //create list ()
260. var result = new List>();
261. //add display order and path to list
262. foreach (var descriptionFile in pluginFolder.GetFiles("Description.txt", SearchOption.AllDirectories))
263. {
264. if (!IsPackagePluginFolder(descriptionFile.Directory))
265. continue;
266.  
267. //parse file
268. var pluginDescriptor = PluginFileParser.ParsePluginDescriptionFile(descriptionFile.FullName);
269.  
270. //populate list
271. result.Add(new KeyValuePair(descriptionFile, pluginDescriptor));
272. }
273.  
274. result.Sort((firstPair, nextPair) => firstPair.Value.DisplayOrder.CompareTo(nextPair.Value.DisplayOrder));
275. return result;
276. }
277.  
278. ///
279. /// Indicates whether assembly file is already loaded
280. ///
281. /// File info
282. /// Result
283. private static bool IsAlreadyLoaded(FileInfo fileInfo)
284. {
285. try
286. {
287. string fileNameWithoutExt = Path.GetFileNameWithoutExtension(fileInfo.FullName);
288. if (fileNameWithoutExt == null)
289. throw new Exception(string.Format("Cannot get file extnension for {0}", fileInfo.Name));
290. foreach (var a in AppDomain.CurrentDomain.GetAssemblies())
291. {
292. string assemblyName = a.FullName.Split(new[] { ',' }).FirstOrDefault();
293. if (fileNameWithoutExt.Equals(assemblyName, StringComparison.InvariantCultureIgnoreCase))
294. return true;
295. }
296. }
297. catch (Exception exc)
298. {
299. Debug.WriteLine("Cannot validate whether an assembly is already loaded. " + exc);
300. }
301. return false;
302. }
303.  
304. ///
305. /// Perform file deply
306. ///
307. /// Plugin file info
308. /// Assembly
309. private static Assembly PerformFileDeploy(FileInfo plug)
310. {
311. if (plug.Directory.Parent == null)
312. throw new InvalidOperationException("The plugin directory for the " + plug.Name +
313. " file exists in a folder outside of the allowed nopCommerce folder heirarchy");
314.  
315. FileInfo shadowCopiedPlug;
316.  
317. if (CommonHelper.GetTrustLevel() != AspNetHostingPermissionLevel.Unrestricted)
318. {
319. //all plugins will need to be copied to ~/Plugins/bin/
320. //this is aboslutely required because all of this relies on probingPaths being set statically in the web.config
321.  
322. //were running in med trust, so copy to custom bin folder
323. var shadowCopyPlugFolder = Directory.CreateDirectory(_shadowCopyFolder.FullName);
324. shadowCopiedPlug = InitializeMediumTrust(plug, shadowCopyPlugFolder);
325. }
326. else
327. {
328. var directory = AppDomain.CurrentDomain.DynamicDirectory;
329. Debug.WriteLine(plug.FullName + " to " + directory);
330. //were running in full trust so copy to standard dynamic folder
331. shadowCopiedPlug = InitializeFullTrust(plug, new DirectoryInfo(directory));
332. }
333.  
334. //we can now register the plugin definition
335. var shadowCopiedAssembly = Assembly.Load(AssemblyName.GetAssemblyName(shadowCopiedPlug.FullName));
336.  
337. //add the reference to the build manager
338. Debug.WriteLine("Adding to BuildManager: '{0}'", shadowCopiedAssembly.FullName);
339. BuildManager.AddReferencedAssembly(shadowCopiedAssembly);
340.  
341. return shadowCopiedAssembly;
342. }
343.  
344. ///
345. /// Used to initialize plugins when running in Full Trust
346. ///
347. ///
348. ///
349. ///
350. private static FileInfo InitializeFullTrust(FileInfo plug, DirectoryInfo shadowCopyPlugFolder)
351. {
352. var shadowCopiedPlug = new FileInfo(Path.Combine(shadowCopyPlugFolder.FullName, plug.Name));
353. try
354. {
355. File.Copy(plug.FullName, shadowCopiedPlug.FullName, true);
356. }
357. catch (IOException)
358. {
359. Debug.WriteLine(shadowCopiedPlug.FullName + " is locked, attempting to rename");
360. //this occurs when the files are locked,
361. //for some reason devenv locks plugin files some times and for another crazy reason you are allowed to rename them
362. //which releases the lock, so that it what we are doing here, once it's renamed, we can re-shadow copy
363. try
364. {
365. var oldFile = shadowCopiedPlug.FullName + Guid.NewGuid().ToString("N") + ".old";
366. File.Move(shadowCopiedPlug.FullName, oldFile);
367. }
368. catch (IOException exc)
369. {
370. throw new IOException(shadowCopiedPlug.FullName + " rename failed, cannot initialize plugin", exc);
371. }
372. //ok, we've made it this far, now retry the shadow copy
373. File.Copy(plug.FullName, shadowCopiedPlug.FullName, true);
374. }
375. return shadowCopiedPlug;
376. }
377.  
378. ///
379. /// Used to initialize plugins when running in Medium Trust
380. ///
381. ///
382. ///
383. ///
384. private static FileInfo InitializeMediumTrust(FileInfo plug, DirectoryInfo shadowCopyPlugFolder)
385. {
386. var shouldCopy = true;
387. var shadowCopiedPlug = new FileInfo(Path.Combine(shadowCopyPlugFolder.FullName, plug.Name));
388.  
389. //check if a shadow copied file already exists and if it does, check if it's updated, if not don't copy
390. if (shadowCopiedPlug.Exists)
391. {
392. //it's better to use LastWriteTimeUTC, but not all file systems have this property
393. //maybe it is better to compare file hash?
394. var areFilesIdentical = shadowCopiedPlug.CreationTimeUtc.Ticks >= plug.CreationTimeUtc.Ticks;
395. if (areFilesIdentical)
396. {
397. Debug.WriteLine("Not copying; files appear identical: '{0}'", shadowCopiedPlug.Name);
398. shouldCopy = false;
399. }
400. else
401. {
402. File.Delete(shadowCopiedPlug.FullName);
403. }
404. }
405.  
406. if (shouldCopy)
407. {
408. try
409. {
410. File.Copy(plug.FullName, shadowCopiedPlug.FullName, true);
411. }
412. catch (IOException)
413. {
414. Debug.WriteLine(shadowCopiedPlug.FullName + " is locked, attempting to rename");
415. //this occurs when the files are locked,
416. //for some reason devenv locks plugin files some times and for another crazy reason you are allowed to rename them
417. //which releases the lock, so that it what we are doing here, once it's renamed, we can re-shadow copy
418. try
419. {
420. var oldFile = shadowCopiedPlug.FullName + Guid.NewGuid().ToString("N") + ".old";
421. File.Move(shadowCopiedPlug.FullName, oldFile);
422. }
423. catch (IOException exc)
424. {
425. throw new IOException(shadowCopiedPlug.FullName + " rename failed, cannot initialize plugin", exc);
426. }
427. //ok, we've made it this far, now retry the shadow copy
428. File.Copy(plug.FullName, shadowCopiedPlug.FullName, true);
429. }
430. }
431.  
432. return shadowCopiedPlug;
433. }
434.  
435. ///
436. /// Determines if the folder is a bin plugin folder for a package
437. ///
438. ///
439. ///
440. private static bool IsPackagePluginFolder(DirectoryInfo folder)
441. {
442. if (folder == null) return false;
443. if (folder.Parent == null) return false;
444. if (!folder.Parent.Name.Equals("Plugins", StringComparison.InvariantCultureIgnoreCase)) return false;
445. return true;
446. }
447.  
448. ///
449. /// Gets the full path of InstalledPlugins.txt file
450. ///
451. ///
452. private static string GetInstalledPluginsFilePath()
453. {
454. var filePath = HostingEnvironment.MapPath(InstalledPluginsFilePath);
455. return filePath;
456. }
457.  
458. #endregion
459. }
460. }

在程序运行的时候最开始就要执行PluginFinder的初始化Initialize方法，获取插件目录所有的插件及描述信息及其它初始化操作。可以把PluginFinder理解成主要用来管理插件的，就像windows任务管理器一样。

Nop.Core.Plugins.PluginFileParser

 

源码：

1. using System;
2. using System.Collections.Generic;
3. using System.IO;
4. using System.Linq;
5. using System.Text;
6.  
7. namespace Nop.Core.Plugins
8. {
9. ///
10. /// Plugin files parser
11. ///
12. public static class PluginFileParser
13. {
14. public static IList ParseInstalledPluginsFile(string filePath)
15. {
16. //read and parse the file
17. if (!File.Exists(filePath))
18. return new List();
19.  
20. var text = File.ReadAllText(filePath);
21. if (String.IsNullOrEmpty(text))
22. return new List();
23.  
24. //Old way of file reading. This leads to unexpected behavior when a user's FTP program transfers these files as ASCII (\r\n becomes \n).
25. //var lines = text.Split(new[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries);
26.  
27. var lines = new List();
28. using (var reader = new StringReader(text))
29. {
30. string str;
31. while ((str = reader.ReadLine()) != null)
32. {
33. if (String.IsNullOrWhiteSpace(str))
34. continue;
35. lines.Add(str.Trim());
36. }
37. }
38. return lines;
39. }
40.  
41. public static void SaveInstalledPluginsFile(IList pluginSystemNames, string filePath)
42. {
43. string result = "";
44. foreach (var sn in pluginSystemNames)
45. result += string.Format("{0}{1}", sn, Environment.NewLine);
46.  
47. File.WriteAllText(filePath, result);
48. }
49.  
50. public static PluginDescriptor ParsePluginDescriptionFile(string filePath)
51. {
52. var descriptor = new PluginDescriptor();
53. var text = File.ReadAllText(filePath);
54. if (String.IsNullOrEmpty(text))
55. return descriptor;
56.  
57. var settings = new List();
58. using (var reader = new StringReader(text))
59. {
60. string str;
61. while ((str = reader.ReadLine()) != null)
62. {
63. if (String.IsNullOrWhiteSpace(str))
64. continue;
65. settings.Add(str.Trim());
66. }
67. }
68.  
69. //Old way of file reading. This leads to unexpected behavior when a user's FTP program transfers these files as ASCII (\r\n becomes \n).
70. //var settings = text.Split(new[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries);
71.  
72. foreach (var setting in settings)
73. {
74. var separatorIndex = setting.IndexOf(':');
75. if (separatorIndex == -1)
76. {
77. continue;
78. }
79. string key = setting.Substring(0, separatorIndex).Trim();
80. string value = setting.Substring(separatorIndex + 1).Trim();
81.  
82. switch (key)
83. {
84. case "Group":
85. descriptor.Group = value;
86. break;
87. case "FriendlyName":
88. descriptor.FriendlyName = value;
89. break;
90. case "SystemName":
91. descriptor.SystemName = value;
92. break;
93. case "Version":
94. descriptor.Version = value;
95. break;
96. case "SupportedVersions":
97. {
98. //parse supported versions
99. descriptor.SupportedVersions = value.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries)
100. .Select(x => x.Trim())
101. .ToList();
102. }
103. break;
104. case "Author":
105. descriptor.Author = value;
106. break;
107. case "DisplayOrder":
108. {
109. int displayOrder;
110. int.TryParse(value, out displayOrder);
111. descriptor.DisplayOrder = displayOrder;
112. }
113. break;
114. case "FileName":
115. descriptor.PluginFileName = value;
116. break;
117. case "LimitedToStores":
118. {
119. //parse list of store IDs
120. foreach (var str1 in value.Split(new char[] {','}, StringSplitOptions.RemoveEmptyEntries)
121. .Select(x => x.Trim()))
122. {
123. int storeId = 0;
124. if (int.TryParse(str1, out storeId))
125. {
126. descriptor.LimitedToStores.Add(storeId);
127. }
128. }
129. }
130. break;
131. default:
132. break;
133. }
134. }
135.  
136. //nopCommerce 2.00 didn't have 'SupportedVersions' parameter
137. //so let's set it to "2.00"
138. if (descriptor.SupportedVersions.Count == 0)
139. descriptor.SupportedVersions.Add("2.00");
140.  
141. return descriptor;
142. }
143.  
144. public static void SavePluginDescriptionFile(PluginDescriptor plugin)
145. {
146. if (plugin == null)
147. throw new ArgumentException("plugin");
148.  
149. //get the Description.txt file path
150. if (plugin.OriginalAssemblyFile == null)
151. throw new Exception(string.Format("Cannot load original assembly path for {0} plugin.", plugin.SystemName));
152. var filePath = Path.Combine(plugin.OriginalAssemblyFile.Directory.FullName, "Description.txt");
153. if (!File.Exists(filePath))
154. throw new Exception(string.Format("Description file for {0} plugin does not exist. {1}", plugin.SystemName, filePath));
155.  
156. var keyValues = new List>();
157. keyValues.Add(new KeyValuePair("Group", plugin.Group));
158. keyValues.Add(new KeyValuePair("FriendlyName", plugin.FriendlyName));
159. keyValues.Add(new KeyValuePair("SystemName", plugin.SystemName));
160. keyValues.Add(new KeyValuePair("Version", plugin.Version));
161. keyValues.Add(new KeyValuePair("SupportedVersions", string.Join(",", plugin.SupportedVersions)));
162. keyValues.Add(new KeyValuePair("Author", plugin.Author));
163. keyValues.Add(new KeyValuePair("DisplayOrder", plugin.DisplayOrder.ToString()));
164. keyValues.Add(new KeyValuePair("FileName", plugin.PluginFileName));
165. if (plugin.LimitedToStores.Count > 0)
166. {
167. var storeList = "";
168. for (int i = 0; i < plugin.LimitedToStores.Count; i++)
169. {
170. storeList += plugin.LimitedToStores[i];
171. if (i != plugin.LimitedToStores.Count - 1)
172. storeList += ",";
173. }
174. keyValues.Add(new KeyValuePair("LimitedToStores", storeList));
175. }
176.  
177. var sb = new StringBuilder();
178. for (int i = 0; i < keyValues.Count; i++)
179. {
180. var key = keyValues[i].Key;
181. var value = keyValues[i].Value;
182. sb.AppendFormat("{0}: {1}", key, value);
183. if (i != keyValues.Count -1)
184. sb.Append(Environment.NewLine);
185. }
186. //save the file
187. File.WriteAllText(filePath, sb.ToString());
188. }
189. }
190. }

可以从上面看到这类主要是用来解析插件描述信息文件的。主要有两个作用：

一、PluginDescriptor对象中的插件的信息写到一个文本文件中。

二、解析插件描述信息成文本文件并返回一PluginDescriptor对象。

 

文章转载自：蓝狐软件工作室 » NopCommerce源码架构详解--插件机制相关源码分析二