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chart

chart #

Chart — a Vega-Lite specification, with its data inline or in a staged file.

Chart #

Bases: Component

A Vega-Lite spec drawn by vega-embed; data is an optional CSV/TSV/JSON file.

When data is given it is staged into the page and the spec's data becomes a reference to that file. Scatter is the ready-made plot of columns against each other; this is a specification in full.

cg.ui.Chart(
    spec={
        "mark": "bar",
        "data": {"values": [{"day": "2026-06-10", "sessions": 3}]},
        "encoding": {
            "x": {"field": "day", "type": "temporal"},
            "y": {"field": "sessions", "type": "quantitative"},
        },
    }
)
Source code in capturegraph-lib/capturegraph/ui/chart.py 
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class Chart(Component):
    """A Vega-Lite ``spec`` drawn by vega-embed; ``data`` is an optional CSV/TSV/JSON file.

    When ``data`` is given it is staged into the page and the spec's ``data``
    becomes a reference to that file. ``Scatter`` is the ready-made plot of
    columns against each other; this is a specification in full.

    ```python
    cg.ui.Chart(
        spec={
            "mark": "bar",
            "data": {"values": [{"day": "2026-06-10", "sessions": 3}]},
            "encoding": {
                "x": {"field": "day", "type": "temporal"},
                "y": {"field": "sessions", "type": "quantitative"},
            },
        }
    )
    ```
    """

    spec: dict[str, JSONValue]
    data: Blob | None = None

    def html(self, render: Render) -> str:
        """The specification drawn, its ``data`` staged into the page first."""
        spec: dict[str, JSONValue] = dict(self.spec)
        if self.data is not None:
            href = render.stage(self.data)
            data: dict[str, JSONValue] = {"url": href}
            kind = _FORMATS.get(self.data.suffix.lower())
            if kind is not None:
                data["format"] = {"type": kind}
            spec["data"] = data
        return embed(render, spec)

html(render) #

The specification drawn, its data staged into the page first.

Source code in capturegraph-lib/capturegraph/ui/chart.py 
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def html(self, render: Render) -> str:
    """The specification drawn, its ``data`` staged into the page first."""
    spec: dict[str, JSONValue] = dict(self.spec)
    if self.data is not None:
        href = render.stage(self.data)
        data: dict[str, JSONValue] = {"url": href}
        kind = _FORMATS.get(self.data.suffix.lower())
        if kind is not None:
            data["format"] = {"type": kind}
        spec["data"] = data
    return embed(render, spec)