Implement rich display (jupyter-xeus#17)

* Implement display repr

* Add missing repr handle

* Create display_pub_data function

* Add a global "display" function

* Review

* Remove useless if condition

* Add warning for _ipython_display

Author: martinRenou

notebooks/marie.png

@@ -1,5 +1,16 @@
 {
  "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from IPython.display import Image\n",
+    "im = Image(url=\"marie.png\")\n",
+    "im"
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": null,
@@ -63,6 +74,8 @@
    "source": [
     "b = 89\n",
     "\n",
+    "display(im)\n",
+    "\n",
     "def test(x):\n",
     "    return x * 2\n",
     "\n",
@@ -114,6 +127,24 @@
     "b"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from ipywidgets import IntSlider"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "IntSlider()"
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": null,

notebooks/xeus-python.ipynb

@@ -7,6 +7,10 @@
 * The full license is in the file LICENSE, distributed with this software. *
 ****************************************************************************/
 
+#include <string>
+
+#include "xeus/xjson.hpp"
+
 #include "pybind11/pybind11.h"
 #include "pybind11/embed.h"
 
@@ -42,6 +46,64 @@ namespace xpyt
         }
     }
 
+    xeus::xjson display_pub_data(py::object obj)
+    {
+        py::module py_json = py::module::import("json");
+        xeus::xjson pub_data;
+
+        if (hasattr(obj, "_repr_mimebundle_"))
+        {
+            pub_data = xeus::xjson::parse(static_cast<std::string>(
+                py::str(py_json.attr("dumps")(obj.attr("_repr_mimebundle_")()))
+            ));
+        }
+        else
+        {
+            if (hasattr(obj, "_repr_html_"))
+            {
+                pub_data["text/html"] = static_cast<std::string>(
+                    py::str(obj.attr("_repr_html_")())
+                );
+            }
+            if (hasattr(obj, "_repr_json_"))
+            {
+                pub_data["application/json"] = static_cast<std::string>(
+                    py::str(obj.attr("_repr_json_")())
+                );
+            }
+            if (hasattr(obj, "_repr_jpeg_"))
+            {
+                pub_data["image/jpeg"] = static_cast<std::string>(
+                    py::str(obj.attr("_repr_jpeg_")())
+                );
+            }
+            if (hasattr(obj, "_repr_png_"))
+            {
+                pub_data["image/png"] = static_cast<std::string>(
+                    py::str(obj.attr("_repr_png_")())
+                );
+            }
+            if (hasattr(obj, "_repr_svg_"))
+            {
+                pub_data["image/svg+xml"] = static_cast<std::string>(
+                    py::str(obj.attr("_repr_svg_")())
+                );
+            }
+            if (hasattr(obj, "_repr_latex_"))
+            {
+                pub_data["text/latex"] = static_cast<std::string>(
+                    py::str(obj.attr("_repr_latex_")())
+                );
+            }
+
+            pub_data["text/plain"] = static_cast<std::string>(
+                py::str(obj.attr("__repr__")())
+            );
+        }
+
+        return pub_data;
+    }
+
     PYBIND11_EMBEDDED_MODULE(xeus_python_display, m) {
         py::class_<xdisplayhook>(m, "XPythonDisplay")
             .def(py::init<>())

src/xdisplay.cpp

@@ -38,6 +38,8 @@ namespace xpyt
         int m_execution_count;
         hooks_type m_hooks;
     };
+
+    xeus::xjson display_pub_data(py::object obj);
 }
 
 #endif

src/xdisplay.hpp

@@ -18,6 +18,7 @@
 #include "xpyt_config.hpp"
 #include "xinterpreter.hpp"
 #include "xlogger.hpp"
+#include "xdisplay.hpp"
 
 namespace py = pybind11;
 
@@ -244,14 +245,19 @@ namespace xpyt
         py::cpp_function publish_display = [this](int execution_counter, py::object obj){
             if (!obj.is_none())
             {
-                xeus::xjson pub_data;
-                pub_data["text/plain"] = py::str(obj);
-                publish_execution_result(execution_counter, std::move(pub_data), xeus::xjson::object());
+                if (hasattr(obj, "_ipython_display_"))
+                {
+                    this->publish_stream("stderr", "_ipython_display_ is not supported");
+                }
+
+                this->publish_execution_result(execution_counter, std::move(display_pub_data(obj)), xeus::xjson::object());
             }
         };
 
         m_displayhook.attr("add_hook")(publish_display);
-
         sys.attr("displayhook") = m_displayhook;
+
+        // Create a global "display" function
+        py::globals()["display"] = m_displayhook;
     }
 }