Add support for multiline string properties

assets/tiled_base64_gzip.tmx

@@ -15,6 +15,11 @@
   <properties>
    <property name="prop1" value="12"/>
    <property name="prop2" value="some text"/>
+   <property name="prop3">Line 1
+Line 2
+Line 3,
+  etc
+   </property>
   </properties>
   <data encoding="base64" compression="gzip">
    H4sIAAAAAAAACu3XMQrDMAwFUF0hJwglc9L7364NjUG4dulQu8t7IMiQSR8heYuIrapbpxhvuWq/6njWvVNymaNkUs/JqZURc5wZLOm7rpKLGRlvjVfP107t8T47jJH7vTcqZ3KETEYrfa/7XO/6vEtkMk7u87kbcq9LJjV5jFPfUOWube30CFnM0Lpr6/dGyaE3M/zep1zy210e47Tu2FYuW3gTzvDtLrAz5ujt7d5/zPUpG3n837fzw3zyAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAgewAvf+EvQJwAAA==

assets/tiled_base64_zlib.tmx

@@ -15,6 +15,11 @@
   <properties>
    <property name="prop1" value="12"/>
    <property name="prop2" value="some text"/>
+   <property name="prop3">Line 1
+Line 2
+Line 3,
+  etc
+   </property>
   </properties>
   <data encoding="base64" compression="zlib">
    eJzt1zEKwzAMBVBdIScIJXPS+9+uDY1BuHbpULvLeyDIkEkfIXmLiK2qW6cYb7lqv+p41r1TcpmjZFLPyamVEXOcGSzpu66SixkZb41Xz9dO7fE+O4yR+703KmdyhExGK32v+1zv+rxLZDJO7vO5G3KvSyY1eYxT31Dlrm3t9AhZzNC6a+v3RsmhNzP83qdc8ttdHuO07thWLlt4E87w7S6wM+bo7e3ef8z1KRt5/N+388N88gAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAIHsArPIXTA==

assets/tiled_base64_zstandard.tmx

@@ -15,6 +15,11 @@
   <properties>
    <property name="prop1" value="12"/>
    <property name="prop2" value="some text"/>
+   <property name="prop3">Line 1
+Line 2
+Line 3,
+  etc
+   </property>
   </properties>
   <data encoding="base64" compression="zstd">
    KLUv/WBAm6UFAPgjAAAAIREtLgAAAC8RACMfHy0tLi0tLSMjIyMjIyMjSaBguwAAg0JmtQEFA2qvb+Al6lHUO91VvxpMveegXVabfkkjaEj1wZVZeNWPbSrdISdZk1b145uYEEFAvQmwiF5zTMi2QsOb9Vhv7ZxsK27ZJBXC9lYf2mVdhuqWjb8/hITgZAMw1ctxfXIOXBaofKbranfWDTtJ/Xyz7E2ZNWzVKauthC4r26Ry1TnnDqtmvUfyDw==

assets/tiled_csv.tmx

@@ -15,6 +15,11 @@
   <properties>
    <property name="prop1" value="12"/>
    <property name="prop2" value="some text"/>
+   <property name="prop3">Line 1
+Line 2
+Line 3,
+  etc
+   </property>
   </properties>
   <data encoding="csv">
 35,35,35,35,35,33,33,33,33,33,33,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,

src/properties.rs

@@ -1,6 +1,6 @@
 use std::{collections::HashMap, io::Read, str::FromStr};
 
-use xml::{attribute::OwnedAttribute, EventReader};
+use xml::{EventReader, attribute::OwnedAttribute, reader::XmlEvent};
 
 use crate::{
     error::{ParseTileError, TiledError},
@@ -87,18 +87,29 @@ pub(crate) fn parse_properties<R: Read>(
     let mut p = HashMap::new();
     parse_tag!(parser, "properties", {
         "property" => |attrs:Vec<OwnedAttribute>| {
-            let (t, (k, v)) = get_attrs!(
+            let ((t, v_attr), k) = get_attrs!(
                 attrs,
                 optionals: [
                     ("type", property_type, |v| Some(v)),
+                    ("value", value, |v| Some(v)),
                 ],
                 required: [
                     ("name", key, |v| Some(v)),
-                    ("value", value, |v| Some(v)),
                 ],
                 TiledError::MalformedAttributes("property must have a name and a value".to_string())
             );
             let t = t.unwrap_or("string".into());
+
+            let v = match v_attr {
+                Some(val) => val,
+                None => {
+                    // if the "value" attribute was missing, might be a multiline string
+                    match parser.next().map_err(TiledError::XmlDecodingError)? {
+                        XmlEvent::Characters(s) => Ok(s),
+                        _ => Err(TiledError::MalformedAttributes(format!("property '{}' is missing a value", k))),
+                    }?
+                }
+            };
 
             p.insert(k, PropertyValue::new(t, v)?);
             Ok(())

tests/lib.rs

@@ -110,6 +110,19 @@ fn test_tile_property() {
     assert_eq!("123", prop_value);
 }
 
+#[test]
+fn test_layer_property() {
+    let r = read_from_file(&Path::new("assets/tiled_base64.tmx")).unwrap();
+    let prop_value: String = if let Some(&PropertyValue::StringValue(ref v)) =
+        r.layers[0].properties.get("prop3")
+    {
+        v.clone()
+    } else {
+        String::new()
+    };
+    assert_eq!("Line 1\r\nLine 2\r\nLine 3,\r\n  etc\r\n   ", prop_value);
+}
+
 #[test]
 fn test_object_group_property() {
     let r = read_from_file(&Path::new("assets/tiled_object_groups.tmx")).unwrap();