add support for xmltext diff

ext/yrb/src/lib.rs

@@ -488,6 +488,9 @@ fn init() -> Result<(), Error> {
             method!(YXmlText::yxml_text_attributes, 1),
         )
         .expect("cannot define private method: yxml_text_attributes");
+    yxml_text
+        .define_private_method("yxml_text_diff", method!(YXmlText::yxml_text_diff, 1))
+        .expect("cannot define private method: yxml_text_diff");
     yxml_text
         .define_private_method("yxml_text_format", method!(YXmlText::yxml_text_format, 4))
         .expect("cannot define private method: yxml_text_format");

ext/yrb/src/yxml_text.rs

@@ -1,9 +1,11 @@
 use crate::utils::map_rhash_to_attrs;
+use crate::ydiff::YDiff;
 use crate::yvalue::YValue;
 use crate::yxml_fragment::YXmlFragment;
 use crate::{YTransaction, YXmlElement};
-use magnus::{Error, IntoValue, RHash, Value};
+use magnus::{Error, IntoValue, RHash, Value, RArray};
 use std::cell::RefCell;
+use yrs::types::text::YChange;
 use yrs::{Any, GetString, Text, Xml, XmlNode, XmlTextRef};
 
 #[magnus::wrap(class = "Y::XMLText")]
@@ -13,6 +15,38 @@ pub(crate) struct YXmlText(pub(crate) RefCell<XmlTextRef>);
 unsafe impl Send for YXmlText {}
 
 impl YXmlText {
+    pub(crate) fn yxml_text_diff(&self, transaction: &YTransaction) -> RArray {
+        let tx = transaction.transaction();
+        let tx = tx.as_ref().unwrap();
+
+        RArray::from_iter(
+            self.0
+                .borrow()
+                .diff(tx, YChange::identity)
+                .iter()
+                .map(move |diff| {
+                    let yvalue = YValue::from(diff.insert.clone());
+                    let insert = yvalue.0.into_inner();
+                    let attributes = diff.attributes.as_ref().map_or_else(
+                        || None,
+                        |boxed_attrs| {
+                            let attributes = RHash::new();
+                            for (key, value) in boxed_attrs.iter() {
+                                let key = key.to_string();
+                                let value = YValue::from(value.clone()).0.into_inner();
+                                attributes.aset(key, value).expect("cannot add value");
+                            }
+                            Some(attributes)
+                        },
+                    );
+                    YDiff {
+                        ydiff_insert: insert,
+                        ydiff_attrs: attributes,
+                    }
+                    .into_value()
+                }),
+        )
+    }
     pub(crate) fn yxml_text_attributes(&self, transaction: &YTransaction) -> RHash {
         let tx = transaction.transaction();
         let tx = tx.as_ref().unwrap();

lib/y/xml.rb

@@ -526,6 +526,15 @@ def detach(subscription_id)
       yxml_text_unobserve(subscription_id)
     end
 
+    # Diff
+    #
+    # @return[Array<YDiff>]
+    def diff
+      document.current_transaction do |tx|
+        yxml_text_diff(tx)
+      end
+    end
+
     # Format text
     #
     # @param index [Integer]
@@ -791,6 +800,12 @@ def can_insert?(value)
     #
     # @return [Hash]
 
+    # @!method yxml_text_diff(tx)
+    #   Returns text changes as list of diffs
+    #
+    # @param transaction [Y::Transaction]
+    # @return [Array<YDiff>]
+
     # @!method yxml_text_format(tx, index, length, attrs)
     #
     # @param tx [Y::Transaction]

spec/y/xml_text_spec.rb

@@ -46,6 +46,21 @@
     expect(xml_text.to_s).to eq("Hello, <format>World!</format>")
   end
 
+  it "get a list of changes" do
+    doc = Y::Doc.new
+    xml_text = doc.get_xml_text("my text")
+
+    xml_text.insert(0, "Hello, World!", { format: "bold" })
+    xml_text.insert(13, " From Hannes.", { format: "italic" })
+
+    expect(xml_text.diff.map(&:to_h)).to eq([
+                                              { insert: "Hello, World!",
+                                                attrs: { "format" => "bold" } },
+                                              { insert: " From Hannes.",
+                                                attrs: { "format" => "italic" } }
+                                            ])
+  end
+
   it "inserts string at position" do
     doc = Y::Doc.new
     xml_text = doc.get_xml_text("my xml text")