1 files changed, 38 insertions, 1 deletions
diff --git a/src/micropub/mod.rs b/src/micropub/mod.rs
index 8f95085..944506d 100644
--- a/src/micropub/mod.rs
+++ b/src/micropub/mod.rs
@@ -358,7 +358,44 @@ pub struct MicropubUpdate {
     pub add: Option<HashMap<String, Vec<serde_json::Value>>>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub delete: Option<MicropubPropertyDeletion>,
-
+}
+impl MicropubUpdate {
+    /// Update a specified MF2-JSON document with this update.
+    pub fn apply(self, post: &mut serde_json::Value) {
+        if let Some(MicropubPropertyDeletion::Properties(ref delete)) = self.delete {
+            if let Some(props) = post["properties"].as_object_mut() {
+                for key in delete {
+                    props.remove(key);
+                }
+            }
+        } else if let Some(MicropubPropertyDeletion::Values(ref delete)) = self.delete {
+            if let Some(props) = post["properties"].as_object_mut() {
+                for (key, values) in delete {
+                    if let Some(prop) = props.get_mut(key).and_then(serde_json::Value::as_array_mut) {
+                        prop.retain(|v| { values.iter().all(|i| i != v) })
+                    }
+                }
+            }
+        }
+        if let Some(replace) = self.replace {
+            if let Some(props) = post["properties"].as_object_mut() {
+                for (key, value) in replace {
+                    props.insert(key, serde_json::Value::Array(value));
+                }
+            }
+        }
+        if let Some(add) = self.add {
+            if let Some(props) = post["properties"].as_object_mut() {
+                for (key, value) in add {
+                    if let Some(prop) = props.get_mut(&key).and_then(serde_json::Value::as_array_mut) {
+                        prop.extend_from_slice(value.as_slice());
+                    } else {
+                        props.insert(key, serde_json::Value::Array(value));
+                    }
+                }
+            }
+        }
+    }
 }
 
 impl From<MicropubFormAction> for MicropubAction {