add a plugin example

plugins/hello/main.py

@@ -0,0 +1,40 @@
+# encoding:utf-8
+
+import plugins
+from plugins import *
+from common.log import logger
+
+
+@plugins.register(name="Hello", desc="A simple plugin that says hello", version="0.1", author="lanvent")
+class Hello(Plugin):
+    def __init__(self):
+        super().__init__()
+        self.handlers[Event.ON_HANDLE_CONTEXT] = self.on_handle_context
+        # self.handlers[Event.ON_HANDLE_CONTEXT] = self.on_handle_context
+        logger.info("[hello] inited")
+
+    def on_handle_context(self, e_context: EventContext):
+
+        logger.debug("on_handle_context. content: %s" % e_context['context']['content'])
+
+        if e_context['context']['content'] == "Hello":
+            e_context['reply']['type'] = "TEXT"
+            msg = e_context['context']['msg']
+            if e_context['context']['isgroup']:
+                e_context['reply']['content'] = "Hello, " + msg['ActualNickName'] + " from " + msg['User'].get('NickName', "Group")
+            else:
+                e_context['reply']['content'] = "Hello, " + msg['User'].get('NickName', "My friend")
+            
+            e_context.action = EventAction.BREAK_PASS # 事件结束，并跳过处理context的默认逻辑
+
+        if e_context['context']['content'] == "Hi":
+            e_context['reply']['type'] = "TEXT"
+            e_context['reply']['content'] = "Hi"
+            e_context.action = EventAction.BREAK  # 事件结束，进入默认处理逻辑，一般会覆写reply
+
+        if e_context['context']['content'] == "End":
+            # 如果是文本消息"End"，将请求转换成"IMAGE_CREATE"，并将content设置为"The World"
+            if e_context['context']['type'] == "TEXT":
+                e_context['context']['type'] = "IMAGE_CREATE"
+                e_context['context']['content'] = "The World"
+                e_context.action = EventAction.CONTINUE  # 事件继续，交付给下个插件或默认逻辑