Add DataSet.to_html() method for HTML export

Author: PierreRaybaut

CHANGELOG.md

@@ -59,6 +59,32 @@
   * Makes it immediately clear which fields you can edit and which are display-only
   * Validation errors are still highlighted with orange background when they occur
 
+* **DataSet HTML Export**: Added HTML representation method for datasets:
+  * New `to_html()` method on `DataSet` class generates HTML representation similar to Sigima's TableResult format
+  * Features blue-styled title and comment section derived from the dataset's docstring
+  * Two-column table layout with right-aligned item names and left-aligned values
+  * Special handling for `BoolItem` with checkbox characters (☑ for True, ☐ for False)
+  * Monospace font styling for consistent alignment and professional appearance
+  * Proper handling of None values (displayed as "-") and nested ObjectItem datasets
+  * Example usage:
+
+    ```python
+    class PersonDataSet(DataSet):
+        """Personal Information Dataset
+        
+        This dataset collects basic personal information.
+        """
+        name = StringItem("Full Name", default="John Doe")
+        age = IntItem("Age", default=30)
+        active = BoolItem("Account Active", default=True)
+        
+    dataset = PersonDataSet()
+    html_output = dataset.to_html()  # Generate HTML representation
+    ```
+
+  * Ideal for reports, documentation, and web-based dataset visualization
+  * Comprehensive unit test coverage ensures reliability across all item types
+
 * `guidata.configtools.get_icon`:
   * This function retrieves a QIcon from the specified image file.
   * Now supports Qt standard icons (e.g. "MessageBoxInformation" or "DialogApplyButton").

guidata/dataset/dataitems.py

@@ -632,6 +632,15 @@ def __init__(
         )
         self.set_prop("display", text=text)
 
+    def get_string_value(self, instance: DataSet) -> str:
+        """Override DataItem method"""
+        value_str = "☑" if self.get_value(instance) else "☐"
+        label = self.get_prop_value("display", self, "label")
+        text = self.get_prop_value("display", instance, "text", "")
+        if label and text:
+            value_str += " " + text
+        return value_str
+
     def get_value_from_reader(
         self, reader: HDF5Reader | JSONReader | INIReader
     ) -> bool:

guidata/dataset/datatypes.py

@@ -580,7 +580,7 @@ def get_string_value(self, instance: DataSet) -> str:
             if value is not None:
                 text = self.format_string(instance, value, fmt, func)
             else:
-                text = ""
+                text = "-"
             return text
 
     def get_name(self) -> str:
@@ -1675,6 +1675,86 @@ def accept(self, vis: object) -> None:
         for item in self._items:
             item.accept(vis)
 
+    def to_html(self) -> str:
+        """Return HTML representation of the dataset.
+
+        Similar to Sigima's TableResult transpose format with:
+
+        - Title and comment in blue
+        - Two-column table: item names (right-aligned) and values (left-aligned)
+        - For BoolItem: checkbox in first column with label:text formatting
+
+        Returns:
+            HTML representation
+        """
+        # Create the title with comment
+        html = f'<u><b style="color: blue">{self.__title}</b></u>'
+
+        if self.__comment:
+            # Add comment on new line, also in blue
+            html += f'<br><span style="color: blue">{self.__comment}</span>'
+
+        html += ":"
+
+        # Get items for representation (excluding trailing separators)
+        filtered_items = self._get_items_for_text_representation()
+
+        if not filtered_items:
+            html += "<br><em>No items to display</em>"
+            return html
+
+        # Start table with monospace font
+        html += '<table border="0" style="font-family: monospace;">'
+
+        for item in filtered_items:
+            # Skip group items and separators for HTML representation
+            if isinstance(item, (BeginGroup, EndGroup, SeparatorItem)):
+                continue
+
+            # Skip hidden items
+            try:
+                hide = item.get_prop_value("display", self, "hide")
+                if hide is True:
+                    continue
+            except KeyError:
+                pass
+
+            # Handle ObjectItem (nested datasets)
+            if isinstance(item, ObjectItem):
+                composite_dataset = item.get_value(self)
+                if hasattr(composite_dataset, "to_html"):
+                    item_label = item.get_prop_value("display", self, "label")
+                    html += (
+                        f'<tr><td style="text-align: right; vertical-align: top;">'
+                        f"{item_label}:</td>"
+                    )
+                    nested_html = composite_dataset.to_html(transpose=False)
+                    html += (
+                        f'<td style="text-align: left; padding-left: 10px;">'
+                        f"{nested_html}</td></tr>"
+                    )
+                continue
+
+            # Get item label and value
+            label = item.get_prop_value("display", self, "label")
+            if not label:
+                # For BoolItem without label, use name:text formatting
+                label = item.get_prop_value("display", self, "text", "")
+
+            # Get string representation of value
+            value_str = item.get_string_value(self)
+
+            html += (
+                f'<tr><td style="text-align: right; vertical-align: top;">{label}:</td>'
+            )
+            html += (
+                f'<td style="text-align: left; padding-left: 10px;">'
+                f"{value_str}</td></tr>"
+            )
+
+        html += "</table>"
+        return html
+
     def serialize(self, writer: HDF5Writer | JSONWriter | INIWriter) -> None:
         """Serialize the dataset