table: Add generate_markdown.

image: Add `generate_markdown`.

vega: Add `generate_markdown`.

"Translate" vega plot to `matplotlib` figure to save as `png`.

Introduce `render_markdown`.

Closes #62

pyproject.toml

@@ -64,12 +64,21 @@ warn_unreachable = true
 files = ["src", "tests"]
 
 [[tool.mypy.overrides]]
-module = "tabulate"
+module = [
+  "matplotlib.*",
+  "tabulate"
+]
 ignore_missing_imports = true
 
 [tool.pylint.message_control]
 enable = ["c-extension-no-member", "no-else-return"]
-disable = ["missing-module-docstring", "missing-class-docstring", "invalid-name", "R0801"]
+disable = [
+  "missing-module-docstring",
+  "missing-class-docstring",
+  "invalid-name",
+  "R0801",
+  "C0415"
+]
 
 [tool.pylint.variables]
 dummy-variables-rgx = "_+$|(_[a-zA-Z0-9_]*[a-zA-Z0-9]+?$)|dummy|^ignored_|^unused_"

setup.cfg

@@ -27,6 +27,9 @@ packages = find:
 [options.extras_require]
 table =
     tabulate>=0.8.7
+markdown =
+    %(table)s
+    matplotlib
 docs =
     mkdocs==1.3.0
     mkdocs-gen-files==0.3.4
@@ -35,6 +38,7 @@ docs =
     mkdocstrings-python==0.7.0
 tests =
     %(table)s
+    %(markdown)s
     funcy>=1.17
     pytest==7.1.2
     pytest-sugar==0.9.4
@@ -45,6 +49,7 @@ tests =
     pytest-test-utils>=0.0.6
 dev =
     %(table)s
+    %(markdown)s
     %(tests)s
     %(docs)s
 

src/dvc_render/base.py

@@ -1,6 +1,6 @@
 import abc
 from pathlib import Path
-from typing import TYPE_CHECKING, Iterable, List, Union
+from typing import TYPE_CHECKING, Iterable, List, Optional, Union
 
 if TYPE_CHECKING:
     from os import PathLike
@@ -61,6 +61,12 @@ def generate_html(self, html_path=None) -> str:
             return self.DIV.format(id=div_id, partial=partial)
         return ""
 
+    def generate_markdown(
+        self, output_path: Optional[StrPath] = None
+    ) -> str:  # pylint: disable=missing-function-docstring
+        "Generate a markdown element"
+        raise NotImplementedError
+
     @classmethod
     def matches(
         cls, filename, properties  # pylint: disable=unused-argument

src/dvc_render/exceptions.py

@@ -1,2 +1,9 @@
 class DvcRenderException(Exception):
     pass
+
+
+class MissingPlaceholderError(DvcRenderException):
+    def __init__(self, placeholder, template_type):
+        super().__init__(
+            f"{template_type} template has to contain '{placeholder}'."
+        )

src/dvc_render/html.py

@@ -1,5 +1,5 @@
 from pathlib import Path
-from typing import TYPE_CHECKING, Dict, List, Optional
+from typing import TYPE_CHECKING, List, Optional
 
 from .exceptions import DvcRenderException
 
@@ -81,7 +81,6 @@ def embed(self) -> str:
 def render_html(
     renderers: List["Renderer"],
     output_file: "StrPath",
-    metrics: Optional[Dict[str, Dict]] = None,
     template_path: Optional["StrPath"] = None,
     refresh_seconds: Optional[int] = None,
 ) -> "StrPath":
@@ -95,8 +94,6 @@ def render_html(
             page_html = fobj.read()
 
     document = HTML(page_html, refresh_seconds=refresh_seconds)
-    if metrics:
-        document.with_element("<br>")
 
     for renderer in renderers:
         document.with_scripts(renderer.SCRIPTS)

src/dvc_render/image.py

@@ -49,3 +49,14 @@ def partial_html(self, html_path=None, **kwargs) -> str:
             div_content.insert(0, f"<p>{self.name}</p>")
             return "\n".join(div_content)
         return ""
+
+    def generate_markdown(self, output_path=None) -> str:
+        content = []
+        for datapoint in self.datapoints:
+            src = datapoint[self.SRC_FIELD]
+            if src.startswith("data:image;base64"):
+                raise ValueError("`generate_markdown` doesn't support base64")
+            content.append(f"\n![{datapoint[self.TITLE_FIELD]}]({src})")
+        if content:
+            return "\n".join(content)
+        return ""

src/dvc_render/markdown.py

@@ -0,0 +1,73 @@
+from pathlib import Path
+from typing import TYPE_CHECKING, List, Optional
+
+from .exceptions import MissingPlaceholderError
+
+if TYPE_CHECKING:
+    from .base import Renderer, StrPath
+
+
+PAGE_MARKDOWN = """# DVC Report
+
+{renderers}
+"""
+
+
+class Markdown:
+    RENDERERS_PLACEHOLDER = "renderers"
+    RENDERERS_PLACEHOLDER_FORMAT_STR = f"{{{RENDERERS_PLACEHOLDER}}}"
+
+    def __init__(
+        self,
+        template: Optional[str] = None,
+    ):
+        template = template or PAGE_MARKDOWN
+        if self.RENDERERS_PLACEHOLDER_FORMAT_STR not in template:
+            raise MissingPlaceholderError(
+                self.RENDERERS_PLACEHOLDER_FORMAT_STR, "Markdown"
+            )
+
+        self.template = template
+        self.elements: List[str] = []
+
+    def with_element(self, md: str) -> "Markdown":
+        "Adds custom markdown element."
+        self.elements.append(md)
+        return self
+
+    def embed(self) -> str:
+        "Format Markdown template with all elements."
+        kwargs = {
+            self.RENDERERS_PLACEHOLDER: "\n".join(self.elements),
+        }
+        for placeholder, value in kwargs.items():
+            self.template = self.template.replace(
+                "{" + placeholder + "}", value
+            )
+        return self.template
+
+
+def render_markdown(
+    renderers: List["Renderer"],
+    output_file: "StrPath",
+    template_path: Optional["StrPath"] = None,
+) -> "StrPath":
+    "User renderers to fill an Markdown template and write to path."
+    output_path = Path(output_file)
+    output_path.parent.mkdir(exist_ok=True)
+
+    page = None
+    if template_path:
+        with open(template_path, encoding="utf-8") as fobj:
+            page = fobj.read()
+
+    document = Markdown(page)
+
+    for renderer in renderers:
+        document.with_element(
+            renderer.generate_markdown(output_path=output_path)
+        )
+
+    output_path.write_text(document.embed(), encoding="utf8")
+
+    return output_file

src/dvc_render/plotly.py

@@ -1,8 +1,8 @@
 import json
-from collections import defaultdict
 from typing import Any, Dict, Optional
 
 from .base import Renderer
+from .utils import list_dict_to_dict_list
 
 
 class ParallelCoordinatesRenderer(Renderer):
@@ -46,10 +46,7 @@ def partial_html(self, **kwargs) -> str:
         return json.dumps(self._get_plotly_data())
 
     def _get_plotly_data(self):
-        tabular_dict = defaultdict(list)
-        for row in self.datapoints:
-            for col_name, value in row.items():
-                tabular_dict[col_name].append(str(value))
+        tabular_dict = list_dict_to_dict_list(self.datapoints)
 
         trace: Dict[str, Any] = {"type": "parcoords", "dimensions": []}
         for label, values in tabular_dict.items():

src/dvc_render/table.py

@@ -1,4 +1,5 @@
 from .base import Renderer
+from .utils import list_dict_to_dict_list
 
 try:
     from tabulate import tabulate
@@ -22,12 +23,17 @@ class TableRenderer(Renderer):
 
     EXTENSIONS = {".yml", ".yaml", ".json"}
 
-    def partial_html(self, **kwargs) -> str:
-        # From list of dicts to dict of lists
-        data = {
-            k: [datapoint[k] for datapoint in self.datapoints]
-            for k in self.datapoints[0]
-        }
+    @classmethod
+    def to_tabulate(cls, datapoints, tablefmt):
+        """Convert datapoints to tabulate format"""
         if tabulate is None:
-            raise ImportError(f"{self.__class__} requires `tabulate`.")
-        return tabulate(data, headers="keys", tablefmt="html")
+            raise ImportError(f"{cls.__name__} requires `tabulate`.")
+        data = list_dict_to_dict_list(datapoints)
+        return tabulate(data, headers="keys", tablefmt=tablefmt)
+
+    def partial_html(self, **kwargs) -> str:
+        return self.to_tabulate(self.datapoints, tablefmt="html")
+
+    def generate_markdown(self, output_path=None) -> str:
+        table = self.to_tabulate(self.datapoints, tablefmt="github")
+        return f"{self.name}\n\n{table}"

src/dvc_render/utils.py

@@ -0,0 +1,5 @@
+def list_dict_to_dict_list(list_dict):
+    """Convert from list of dictionaries to dictionary of lists."""
+    if not list_dict:
+        return {}
+    return {k: [x[k] for x in list_dict] for k in list_dict[0]}

src/dvc_render/vega.py

@@ -1,9 +1,11 @@
 from copy import deepcopy
+from pathlib import Path
 from typing import List, Optional
 
 from .base import Renderer
 from .exceptions import DvcRenderException
-from .vega_templates import get_template
+from .utils import list_dict_to_dict_list
+from .vega_templates import LinearTemplate, get_template
 
 
 class BadTemplateError(DvcRenderException):
@@ -85,3 +87,36 @@ def get_filled_template(
 
     def partial_html(self, **kwargs) -> str:
         return self.get_filled_template()
+
+    def generate_markdown(self, output_path=None) -> str:
+        if not isinstance(self.template, LinearTemplate):
+            raise ValueError(
+                "`generate_markdown` can only be used with `LinearTemplate`"
+            )
+        try:
+            from matplotlib import pyplot as plt
+        except ImportError as e:
+            raise ImportError(
+                "matplotlib is required for `generate_markdown`"
+            ) from e
+
+        data = list_dict_to_dict_list(self.datapoints)
+        if data:
+            output_file = Path(output_path).parent / self.name
+            output_file = output_file.with_suffix(".png")
+
+            x = self.properties.get("x")
+            y = self.properties.get("y")
+            data[x] = list(map(float, data[x]))
+            data[y] = list(map(float, data[y]))
+
+            plt.title(self.properties.get("title", output_file.stem))
+            plt.xlabel(self.properties.get("x_label", x))
+            plt.ylabel(self.properties.get("y_label", y))
+            plt.plot(x, y, data=data)
+            plt.tight_layout()
+            plt.savefig(output_file)
+            plt.close()
+
+            return f"\n![{self.name}]({output_file.name})"
+        return ""

tests/test_image.py

@@ -29,7 +29,7 @@ def test_matches(extension, matches):
 @pytest.mark.parametrize(
     "src", ["relpath.jpg", "data:image;base64,encoded_image"]
 )
-def test_render(html_path, src):
+def test_generate_html(html_path, src):
     datapoints = [
         {
             "filename": "file.jpg",
@@ -46,6 +46,32 @@ def test_render(html_path, src):
     assert f'<img src="{src}">' in html
 
 
+def test_generate_markdown():
+    datapoints = [
+        {
+            "rev": "workspace",
+            "src": "file.jpg",
+        }
+    ]
+
+    md = ImageRenderer(datapoints, "file.jpg").generate_markdown()
+
+    assert "![workspace](file.jpg)" in md
+
+
+def test_invalid_generate_markdown():
+    datapoints = [
+        {
+            "rev": "workspace",
+            "src": "data:image;base64,encoded_image",
+        }
+    ]
+    with pytest.raises(
+        ValueError, match="`generate_markdown` doesn't support base64"
+    ):
+        ImageRenderer(datapoints, "file.jpg").generate_markdown()
+
+
 @pytest.mark.parametrize(
     "html_path,img_path,expected_path",
     [
@@ -81,6 +107,7 @@ def test_render_evaluate_path(tmp_dir, html_path, img_path, expected_path):
     assert f'<img src="{expected_path}">' in html
 
 
-def test_render_empty():
-    html = ImageRenderer(None, None).generate_html()
-    assert html == ""
+@pytest.mark.parametrize("method", ["generate_html", "generate_markdown"])
+def test_render_empty(method):
+    renderer = ImageRenderer(None, None)
+    assert getattr(renderer, method)() == ""