implement dynamic file upload

owrx/form/gfx.py

@@ -2,6 +2,16 @@ from owrx.form import Input
 
 
 class AvatarInput(Input):
-    def render_input(self, value):
-        pass
+    def __init__(self, id, label, infotext=None):
+        super().__init__(id, label, infotext=infotext)
 
+    def render_input(self, value):
+        return """
+            <div class="imageupload">
+                <input type="hidden" id="{id}" name="{id}">
+                <img class="webrx-rx-avatar" src="static/gfx/openwebrx-avatar.png" alt="Receiver avatar"/>
+                <button class="btn btn-primary">Upload new image...</button>
+            </div>
+        """.format(
+            id=self.id
+        )