From f3e59accad1e8dfe4380506dca3295dcb67fbe6c Mon Sep 17 00:00:00 2001
From: "Dylan M. Taylor" <dylan@dylanmtaylor.com>
Date: Fri, 13 Nov 2026 07:09:05 -0500
Subject: [PATCH] Model IDML EPUB export tag maps

---
 crates/idml/src/model/mod.rs       |  6 +++---
 crates/idml/src/model/resources.rs | 32 ++++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/crates/idml/src/model/mod.rs b/crates/idml/src/model/mod.rs
index 7a1d74724..223cdec08 100644
--- a/crates/idml/src/model/mod.rs
+++ b/crates/idml/src/model/mod.rs
@@ -27,9 +27,9 @@ pub use geometry::{MAX_PATH_POINTS, PathGeometry, PathGeometryError, PathPoint,
 pub use preferences::TextFramePreferences;
 pub use resources::{
     ColorDefinition, ColorGroup, ColorGroupDefinition, ColorGroupMember, ColorSpace, CompositeFontDefinition, CompositeFontEntryDefinition,
-    FontDefinition, FontFamilyDefinition, FontsPart, GradientDefinition, GradientStop, GradientStopDefinition, GradientStopValue, GraphicPart, Ink,
-    InkDefinition, StrokeDefinition, StrokeStyle, StrokeStyleKind, Style, StyleGroup, StyleGroupWriter, StyleKind, StyleNode, Swatch, SwatchKind,
-    TintDefinition, color_groups, inks, named, preference, stroke_styles, style_groups, swatches,
+    EpubExportTagMap, FontDefinition, FontFamilyDefinition, FontsPart, GradientDefinition, GradientStop, GradientStopDefinition, GradientStopValue,
+    GraphicPart, Ink, InkDefinition, StrokeDefinition, StrokeStyle, StrokeStyleKind, Style, StyleGroup, StyleGroupWriter, StyleKind, StyleNode,
+    Swatch, SwatchKind, TintDefinition, color_groups, inks, named, preference, stroke_styles, style_groups, swatches,
 };
 pub use spread::{
     Graphic, GraphicChild, GraphicKind, Guide, ItemChild, ItemKind, Link, MarginPreference, Page, PageChild, PageItem, Spread, SpreadChild, TextPath,
diff --git a/crates/idml/src/model/resources.rs b/crates/idml/src/model/resources.rs
index cf509becc..2ceb652b3 100644
--- a/crates/idml/src/model/resources.rs
+++ b/crates/idml/src/model/resources.rs
@@ -140,6 +140,38 @@ pub enum StyleNode {
     Other(El),
 }
 
+/// EPUB export tagging stored on a style in IDML.
+#[derive(Clone, Debug, Default, PartialEq, Eq)]
+pub struct EpubExportTagMap {
+    pub tag: String,
+    pub class: String,
+    pub split_document: bool,
+}
+
+impl EpubExportTagMap {
+    /// Reads an EPUB `StyleExportTagMap`; other export types are not this record.
+    pub fn from_el(el: &El) -> Option<Self> {
+        let values = Values::of(el);
+        (el.local() == "StyleExportTagMap" && values.get("ExportType") == Some("EPUB")).then(|| Self {
+            tag: values.get("ExportTag").unwrap_or("").to_owned(),
+            class: values.get("ExportClass").unwrap_or("").to_owned(),
+            split_document: values.get("SplitDocument") == Some("true"),
+        })
+    }
+
+    /// Writes the EPUB tag map with its caller-assigned IDML `Self` identifier.
+    pub fn to_el(&self, self_id: &str) -> El {
+        El::new("StyleExportTagMap")
+            .with_attr("Self", self_id)
+            .with_attr("ExportType", "EPUB")
+            .with_attr("ExportTag", &self.tag)
+            .with_attr("ExportClass", &self.class)
+            .with_attr("ExportAttributes", "")
+            .with_attr("SplitDocument", if self.split_document { "true" } else { "false" })
+            .with_attr("EmitCss", "true")
+    }
+}
+
 /// A style, its values as written: `Name`, `Self`, `Properties/BasedOn`, its attributes; and its
 /// other children (an object style's `TextFramePreference`, effect settings, …).
 #[derive(Clone, Debug, PartialEq)]