chart

# Chart Canvas The `chart` renderer provides the `bar-graph` scenario. Despite the scenario name, the data file decides whether the renderer displays bars, lines, or both. ## Spawn `config` is a JSON string containing exactly one absolute data path field: - `data_file` - `dataFile`, an alias of `data_file` Do not provide both fields. Create the data file in the user's workspace; do not try to read a schema from the plugin package. ```typescript canvas_spawn({ kind: 'chart', scenario: 'bar-graph', config: JSON.stringify({ data_file: '/absolute/path/chart-data.json', }), }); ``` ## Data Contract Use this complete document shape: ```json { "schemaVersion": 1, "title": "Quarterly revenue", "subtitle": "Optional subtitle", "table": { "name": "revenue_by_quarter", "idField": "quarter", "rows": [ { "quarter": "Q1", "actual": 120, "target": 110 }, { "quarter": "Q2", "actual": 138, "target": 130 } ] }, "axes": { "x": { "field": "quarter", "label": "Quarter" }, "y": { "label": "Revenue", "min": 0, "max": 200, "format": { "decimals": 0, "prefix": "$", "suffix": "m" } } }, "series": [ { "field": "actual", "label": "Actual", "color": "cyan" }, { "field": "target", "label": "Target", "color": "yellow" } ], "display": { "view": "bar", "showLegend": true, "showValues": "selected", "barWidth": 3, "barGap": 1, "groupGap": 2 }, "metadata": { "source": "Optional scalar metadata" } } ``` Required field paths: - `schemaVersion` - `title` - `table.name` - `table.rows` - `axes.x.field` - `axes.y` - `series[*].field` - `series[*].label` - `display` - `display.view` Rules: - `display.view` must be `bar`, `line`, or `both`. Never default to `both`. - `display.showValues` may be `never`, `selected`, or `always`. - Every `series[*].field` must reference a finite, non-negative numeric value in every row. - `axes.y.min`, when present, must be `0`. - `axes.y.max`, when present, must be a finite number greater than zero. - `axes.y.format.decimals` must be from 0 to 6. - `table.idField`, when present, must identify a unique string or number in every row. - The renderer accepts at most 10,000 rows and 16 series. - Metadata values must be scalar. Unknown fields are rejected. ## Error Recovery Both `canvas_spawn` and `canvas_update` wait for the renderer to parse and load the document. Configuration and data errors are returned by the originating tool, not as Canvas actions: ```json { "success": false, "id": "chart-...", "status": "error", "error": "required field `display.view` is missing" } ``` Repair the field named by `error`, then update the same Canvas. Do not spawn a second Canvas. ```typescript canvas_update({ id: 'chart-...', config: JSON.stringify({ data_file: '/absolute/path/chart-data.json', }), }); ``` ## Interaction - Click a bar to select that row and series. - In line view, use Up/Down to choose the active series and click a category to select it. - Use Left/Right to pan. - Use the mouse wheel or `+`/`-` to zoom. - Press `c` to clear the selection. - Press `a` to attach selected cells, or the visible range, to LLM context. - Press Enter to request LLM analysis of selected or visible data. - Press `e` to export selected or visible rows as a JSON artifact. When `canvas_wait` is available, call it with this Canvas ID while waiting for an interactive selection or analysis request. Otherwise, rely on the host's automatic Canvas event delivery.