Sankey Diagram¶

Flow diagram showing quantities transferred between stages.

When to Use¶

Supply chain flows (raw material → factory → distributor → retail)
Budget allocation (income → categories → subcategories)
User journey funnels

Example¶

from d3_bridge import Sankey

chart = Sankey(
    nodes=[
        {"id": "Farms", "name": "Farms"},
        {"id": "Cooperative", "name": "Cooperative"},
        {"id": "Export", "name": "Export"},
        {"id": "Local", "name": "Local Market"},
    ],
    links=[
        {"source": "Farms", "target": "Cooperative", "value": 80},
        {"source": "Cooperative", "target": "Export", "value": 60},
        {"source": "Cooperative", "target": "Local", "value": 20},
    ],
    title="Cacao Supply Chain",
)

Note

Sankey requires the d3-sankey plugin, which is not loaded by default. Enable it with {% d3_scripts sankey=True %}, or globally for every page via D3_BRIDGE = {"SANKEY": True} in settings. Alternatively, add the script tag yourself before {% d3_scripts %}:

<script src="https://cdn.jsdelivr.net/npm/d3-sankey@0.12"></script>

If the plugin isn't loaded, the chart renders an inline message instead of failing silently.

Parameters¶

Parameter	Type	Default	Description
`nodes`	list or QuerySet	—	Node data
`links`	list or QuerySet	—	Link data with `value`
`node_id`	str	`"id"`	Node identifier field
`node_label`	str	`"name"`	Node label field
`link_source`	str	`"source"`	Link source field
`link_target`	str	`"target"`	Link target field
`link_value`	str	`"value"`	Link value field
`node_padding`	int	`10`	Vertical padding between nodes
`node_width`	int	`20`	Width of node rectangles
`align`	str	`"justify"`	`"left"`, `"right"`, `"center"`, `"justify"`