Dash Plotly Cytoscape initial zoom isn't working

Question

I'm trying to create a Cytoscape on Plotly Dash. The zoom value I gave in Cytoscape props does not affect.

cyto.Cytoscape(
    id='my-cytoscape',
    zoom=500,
    layout={"name": "preset"},
    style={"width": "100%", "height": "600px"},
    stylesheet=[{
        "selector": "node",
        "style": {"width": "data(node_size)",
                  "height": "data(node_size)",
                  "label": "data(label)",
                  "backgroundColor": "blue",
                  "fontSize": "11px"},
    },
        {"selector": "edge",
         "style": {"width": 0.4, "curve-style": "bezier"}},
    ],
)

Answer 1

I think the problem is that the preset layout sets fit to True by default (source).

The documentation tells us the problem with this:

Initial viewport state
zoom : The initial zoom level of the graph. Make sure to disable viewport manipulation options, such as fit, in your layout so that it is not overridden when the layout is applied...

https://github.com/cytoscape/cytoscape.js/blob/e6541de603f5714f572238573ea06ef17503282b/documentation/md/core/init.md#initial-viewport-state

So you just need to set fit to False in your Cytoscape component's layout property:

layout = (
    {
        "name": "preset",
        "fit": False,
    },
)

---

Also your zoom level was too zoomed in for me when I tested it.

Minimal fully reproducible example:

import dash
import dash_cytoscape as cyto
import dash_html_components as html

app = dash.Dash(__name__)

app.layout = html.Div(
    [
        cyto.Cytoscape(
            id="cytoscape-two-nodes",
            zoom=5,
            style={"width": "100%", "height": "600px"},
            layout={
                "name": "preset",
                "fit": False,
            },
            elements=[
                {
                    "data": {"id": "one", "label": "Node 1"},
                    "position": {"x": 75, "y": 75},
                },
                {
                    "data": {"id": "two", "label": "Node 2"},
                    "position": {"x": 200, "y": 200},
                },
                {"data": {"source": "one", "target": "two"}},
            ],
        )
    ]
)

if __name__ == "__main__":
    app.run_server()