Items include a last modified (DTSTAMP) date

src/ical/builder.rs

@@ -2,7 +2,8 @@
 
 use std::error::Error;
 
-use ics::properties::{Comment, Status, Summary};
+use chrono::{DateTime, Utc};
+use ics::properties::{LastModified, Status, Summary};
 use ics::{ICalendar, ToDo};
 
 use crate::item::Item;
@@ -14,9 +15,14 @@ fn ical_product_id() -> String {
 
 /// Create an iCal item from a `crate::item::Item`
 pub fn build_from(item: &Item) -> Result<String, Box<dyn Error>> {
-    let mut todo = ToDo::new(item.uid(), "20181021T190000");
-    todo.push(Summary::new("Take pictures of squirrels (with ÜTF-8 chars)"));
-    todo.push(Comment::new("That's really something I'd like to do one day"));
+    let s_last_modified = format_date_time(item.last_modified());
+
+    let mut todo = ToDo::new(
+        item.uid(),
+        s_last_modified.clone(),
+    );
+    todo.push(LastModified::new(s_last_modified));
+    todo.push(Summary::new(item.name()));
 
     match item {
         Item::Task(t) => {
@@ -34,6 +40,9 @@ pub fn build_from(item: &Item) -> Result<String, Box<dyn Error>> {
     Ok(calendar.to_string())
 }
 
+fn format_date_time(dt: &DateTime<Utc>) -> String {
+    dt.format("%Y%m%dT%H%M%S").to_string()
+}
 
 
 #[cfg(test)]
@@ -44,20 +53,21 @@ mod tests {
     #[test]
     fn test_ical_from_task() {
         let cal_id = "http://my.calend.ar/id".parse().unwrap();
+        let now = format_date_time(&Utc::now());
+
         let task = Item::Task(Task::new(
-            String::from("This is a task"), true, &cal_id
+            String::from("This is a task with ÜTF-8 characters"), true, &cal_id
         ));
         let expected_ical = format!("BEGIN:VCALENDAR\r\n\
             VERSION:2.0\r\n\
             PRODID:-//{}//{}//EN\r\n\
             BEGIN:VTODO\r\n\
             UID:{}\r\n\
-            DTSTAMP:20181021T190000\r\n\
-            SUMMARY:Take pictures of squirrels (with ÜTF-8 chars)\r\n\
-            COMMENT:That's really something I'd like to do one day\r\n\
+            DTSTAMP:{}\r\n\
+            SUMMARY:This is a task with ÜTF-8 characters\r\n\
             STATUS:COMPLETED\r\n\
             END:VTODO\r\n\
-            END:VCALENDAR\r\n", ORG_NAME, PRODUCT_NAME, task.uid());
+            END:VCALENDAR\r\n", ORG_NAME, PRODUCT_NAME, task.uid(), now);
 
         let ical = build_from(&task);
         assert_eq!(ical.unwrap(), expected_ical);

src/ical/parser.rs

@@ -3,6 +3,7 @@
 use std::error::Error;
 
 use ical::parser::ical::component::{IcalCalendar, IcalEvent, IcalTodo};
+use chrono::{DateTime, TimeZone, Utc};
 
 use crate::Item;
 use crate::item::SyncStatus;
@@ -31,6 +32,7 @@ pub fn parse(content: &str, item_id: ItemId, sync_status: SyncStatus) -> Result<
             let mut name = None;
             let mut uid = None;
             let mut completed = false;
+            let mut last_modified = None;
             for prop in &todo.properties {
                 if prop.name == "SUMMARY" {
                     name = prop.value.clone();
@@ -48,6 +50,19 @@ pub fn parse(content: &str, item_id: ItemId, sync_status: SyncStatus) -> Result<
                 if prop.name == "UID" {
                     uid = prop.value.clone();
                 }
+                if prop.name == "DTSTAMP" {
+                    // this property specifies the date and time that the information associated with
+                    // the calendar component was last revised in the calendar store.
+                    last_modified = prop.value.as_ref()
+                        .and_then(|s| {
+                            parse_date_time(s)
+                            .map_err(|err| {
+                                log::warn!("Invalid DTSTAMP: {}", s);
+                                err
+                            })
+                            .ok()
+                        })
+                }
             }
             let name = match name {
                 Some(name) => name,
@@ -57,8 +72,12 @@ pub fn parse(content: &str, item_id: ItemId, sync_status: SyncStatus) -> Result<
                 Some(uid) => uid,
                 None => return Err(format!("Missing UID for item {}", item_id).into()),
             };
+            let last_modified = match last_modified {
+                Some(dt) => dt,
+                None => return Err(format!("Missing DTSTAMP for item {}, but this is required by RFC5545", item_id).into()),
+            };
 
-            Item::Task(Task::new_with_parameters(name, completed, uid, item_id, sync_status))
+            Item::Task(Task::new_with_parameters(name, completed, uid, item_id, sync_status, last_modified))
         },
     };
 
@@ -71,6 +90,12 @@ pub fn parse(content: &str, item_id: ItemId, sync_status: SyncStatus) -> Result<
     Ok(item)
 }
 
+fn parse_date_time(dt: &str) -> Result<DateTime<Utc>, chrono::format::ParseError> {
+    Utc.datetime_from_str(dt, "%Y%m%dT%H%M%S")
+}
+
+
+
 enum CurrentType<'a> {
     Event(&'a IcalEvent),
     Todo(&'a IcalTodo),
@@ -171,6 +196,7 @@ END:VCALENDAR
         assert_eq!(task.uid(), "0633de27-8c32-42be-bcb8-63bc879c6185@some-domain.com");
         assert_eq!(task.completed(), false);
         assert_eq!(task.sync_status(), &sync_status);
+        assert_eq!(task.last_modified(), &Utc.ymd(2021, 03, 21).and_hms(0, 16, 0));
     }
 
     #[test]