Merge pull request #1 from gnuish/master

Comply to RFC Section 3.1 (content lines)

4 files changed, 87 insertions, 20 deletions

diff --git a/src/calendar.rs b/src/calendar.rs
index b904999..a6c3660 100644
--- a/src/calendar.rs
+++ b/src/calendar.rs
@@ -73,17 +73,15 @@ impl Calendar {
 
     /// Writes `Calendar` into a `Writer` using `std::fmt`.
     fn fmt_write<W: fmt::Write>(&self, out: &mut W) -> Result<(), fmt::Error> {
-        writeln!(out, "BEGIN:VCALENDAR")?;
-        writeln!(out, "VERSION:2.0")?;
-        writeln!(out, "PRODID:ICALENDAR-RS")?;
-        writeln!(out, "CALSCALE:GREGORIAN")?;
-        writeln!(out, "\n")?;
+        write_crlf!(out, "BEGIN:VCALENDAR")?;
+        write_crlf!(out, "VERSION:2.0")?;
+        write_crlf!(out, "PRODID:ICALENDAR-RS")?;
+        write_crlf!(out, "CALSCALE:GREGORIAN")?;
 
         for component in &self.components {
             component.fmt_write(out)?;
-            write!(out, "\n")?;
         }
-        writeln!(out, "END:VCALENDAR")?;
+        write_crlf!(out, "END:VCALENDAR")?;
         Ok(())
     }
 
@@ -92,7 +90,7 @@ impl Calendar {
     pub fn print(&self) -> Result<(), fmt::Error> {
         let mut out = String::new();
         try!(self.fmt_write(&mut out));
-        println!("{}", out);
+        print_crlf!("{}", out);
         Ok(())
     }
 }
diff --git a/src/components.rs b/src/components.rs
index 8e9b3fa..0b3ac15 100644
--- a/src/components.rs
+++ b/src/components.rs
@@ -126,10 +126,10 @@ pub trait Component {
     /// Writes `Component` into a `Writer` using `std::fmt`.
     fn fmt_write<W: fmt::Write>(&self, out: &mut W) -> Result<(), fmt::Error> {
 
-        writeln!(out, "BEGIN:{}", Self::component_kind())?;
+        write_crlf!(out, "BEGIN:{}", Self::component_kind())?;
         let now = UTC::now().format("%Y%m%dT%H%M%S");
-        writeln!(out, "DTSTAMP:{}", now)?;
-        writeln!(out, "UID:{}", Uuid::new_v4())?;
+        write_crlf!(out, "DTSTAMP:{}", now)?;
+        write_crlf!(out, "UID:{}", Uuid::new_v4())?;
 
         for property in self.properties().values() {
             property.fmt_write(out)?;
@@ -139,7 +139,7 @@ pub trait Component {
             property.fmt_write(out)?;
         }
 
-        writeln!(out, "END:{}", Self::component_kind())?;
+        write_crlf!(out, "END:{}", Self::component_kind())?;
         Ok(())
     }
 
@@ -222,7 +222,7 @@ pub trait Component {
         self
     }
 
-    ///  Defindes the relative priority.
+    ///  Defines the relative priority.
     ///
     ///  Ranges from 0 to 10, larger values will be truncated
     fn priority(&mut self, priority:u32) -> &mut Self {
@@ -235,7 +235,7 @@ pub trait Component {
     fn print(&self) -> Result<(), fmt::Error> {
         let mut out = String::new();
         try!(self.fmt_write(&mut out));
-        println!("{}", out);
+        print_crlf!("{}", out);
         Ok(())
     }
 
diff --git a/src/lib.rs b/src/lib.rs
index ffcdb98..f124dda 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -15,6 +15,7 @@
 //! # extern crate icalendar;
 //! # use chrono::*;
 //! # use icalendar::*;
+//! # fn main() {
 //! let event = Event::new()
 //!     .summary("test event")
 //!     .description("here I have something really important to do")
@@ -44,7 +45,7 @@
 //! calendar.add(event);
 //! calendar.add(todo);
 //! calendar.add(bday);
-//!
+//! # }
 //! ```
 
 #![warn(missing_docs,
@@ -60,6 +61,24 @@ extern crate chrono;
 extern crate uuid;
 //extern crate vobject;
 
+macro_rules! print_crlf {
+    () => (print!("\r\n"));
+    ($fmt:expr) => (print!(concat!($fmt, "\r\n")));
+    ($fmt:expr, $($arg:tt)*) => (print!(concat!($fmt, "\r\n"), $($arg)*));
+}
+
+macro_rules! write_crlf {
+    ($dst:expr) => (
+        write!($dst, "\r\n")
+    );
+    ($dst:expr, $fmt:expr) => (
+        write!($dst, concat!($fmt, "\r\n"))
+    );
+    ($dst:expr, $fmt:expr, $($arg:tt)*) => (
+        write!($dst, concat!($fmt, "\r\n"), $($arg)*)
+    );
+}
+
 //pub mod period;
 mod components;
 mod properties;
diff --git a/src/properties.rs b/src/properties.rs
index 8348cb5..3ab8a6a 100644
--- a/src/properties.rs
+++ b/src/properties.rs
@@ -1,4 +1,4 @@
-use std::fmt;
+use std::fmt::{self, Write};
 use std::mem;
 use std::collections::HashMap;
 use std::convert::Into;
@@ -71,12 +71,16 @@ impl Property {
     }
 
     /// Writes this Property to `out`
-    pub fn fmt_write<W: fmt::Write>(&self, out: &mut W) -> Result<(), fmt::Error> {
-        try!(write!(out, "{}", self.key));
+    pub fn fmt_write<W: Write>(&self, out: &mut W) -> Result<(), fmt::Error> {
+        // A nice starting capacity for the majority of content lines
+        let mut line = String::with_capacity(150);
+
+        try!(write!(line, "{}", self.key));
         for &Parameter { ref key, ref value } in self.parameters.values() {
-            try!(write!(out, ";{}={}", key, value));
+            try!(write!(line, ";{}={}", key, value));
         }
-        try!(writeln!(out, ":{}", self.value));
+        try!(write!(line, ":{}", self.value));
+        try!(write_crlf!(out, "{}", fold_line(line)));
         Ok(())
     }
 }
@@ -255,3 +259,49 @@ impl Into<Property> for TodoStatus {
 //impl Into<Property> for Attendee {
 //}
 
+
+// Fold a content line as described in RFC 5545, Section 3.1
+fn fold_line(line: String) -> String {
+    let limit = 75;
+    let len = line.len();
+    let mut ret = String::with_capacity(len + (len / limit * 3));
+    let mut bytes_remaining = len;
+
+    let mut pos = 0;
+    let mut next_pos = limit;
+    while bytes_remaining > limit {
+        while line.is_char_boundary(next_pos) == false {
+            next_pos -= 1;
+        }
+        ret.push_str(&line[pos..next_pos]);
+        ret.push_str("\r\n ");
+
+        bytes_remaining -= next_pos - pos;
+        pos = next_pos;
+        next_pos += limit;
+    }
+
+    ret.push_str(&line[len - bytes_remaining..]);
+    ret
+}
+
+#[cfg(test)]
+mod tests {
+    use std::string::String;
+    use super::*;
+
+    #[test]
+    fn fold_line_short() {
+        let line = String::from("This is a short line");
+        assert_eq!(line.clone(), fold_line(line));
+    }
+
+    #[test]
+    fn fold_line_folds_on_char_boundary() {
+        let line = String::from("Content lines shouldn't be folded in the middle \
+        of a UTF-8 character. 老虎.");
+        let expected = String::from("Content lines shouldn't be folded in the middle \
+        of a UTF-8 character. 老\r\n 虎.");
+        assert_eq!(expected, fold_line(line));
+    }
+}