roadmap/assets/js/graph.js

221 lines
6.7 KiB
JavaScript

async function drawGraph(url, baseUrl, pathColors, depth, enableDrag, enableLegend, enableZoom) {
const { index, links, content } = await fetchData
const curPage = url.replace(baseUrl, "")
const parseIdsFromLinks = (links) => [...(new Set(links.flatMap(link => ([link.source, link.target]))))]
const neighbours = new Set()
const wl = [curPage || "/", "__SENTINEL"]
if (depth >= 0) {
while (depth >= 0 && wl.length > 0) {
// compute neighbours
const cur = wl.shift()
if (cur === "__SENTINEL") {
depth--
wl.push("__SENTINEL")
} else {
neighbours.add(cur)
const outgoing = index.links[cur] || []
const incoming = index.backlinks[cur] || []
wl.push(...outgoing.map(l => l.target), ...incoming.map(l => l.source))
}
}
} else {
parseIdsFromLinks(links).forEach(id => neighbours.add(id))
}
const data = {
nodes: [...neighbours].map(id => ({id})),
links: links.filter(l => neighbours.has(l.source) && neighbours.has(l.target)),
}
const color = (d) => {
if (d.id === curPage || (d.id === "/" && curPage === "")) {
return "var(--g-node-active)"
}
for (const pathColor of pathColors) {
const path = Object.keys(pathColor)[0]
const colour = pathColor[path]
if (d.id.startsWith(path)) {
return colour
}
}
return "var(--g-node)"
}
const drag = simulation => {
function dragstarted(event, d) {
if (!event.active) simulation.alphaTarget(1).restart();
d.fx = d.x;
d.fy = d.y;
}
function dragged(event,d) {
d.fx = event.x;
d.fy = event.y;
}
function dragended(event,d) {
if (!event.active) simulation.alphaTarget(0);
d.fx = null;
d.fy = null;
}
const noop = () => {}
return d3.drag()
.on("start", enableDrag ? dragstarted : noop)
.on("drag", enableDrag ? dragged : noop)
.on("end", enableDrag ? dragended : noop);
}
const height = 250
const width = document.getElementById("graph-container").offsetWidth
const simulation = d3.forceSimulation(data.nodes)
.force("charge", d3.forceManyBody().strength(-30))
.force("link", d3.forceLink(data.links).id(d => d.id))
.force("center", d3.forceCenter());
const svg = d3.select('#graph-container')
.append('svg')
.attr('width', width)
.attr('height', height)
.attr("viewBox", [-width / 2, -height / 2, width, height]);
if (enableLegend) {
const legend = [
{"Current": "var(--g-node-active)"},
{"Note": "var(--g-node)"},
...pathColors
]
legend.forEach((legendEntry, i) => {
const key = Object.keys(legendEntry)[0]
const colour = legendEntry[key]
svg.append("circle").attr("cx", -width/2 + 20).attr("cy", height/2 - 30 * (i+1)).attr("r", 6).style("fill", colour)
svg.append("text").attr("x", -width/2 + 40).attr("y", height/2 - 30 * (i+1)).text(key).style("font-size", "15px").attr("alignment-baseline","middle")
})
}
// draw links between nodes
const link = svg.append("g")
.selectAll("line")
.data(data.links)
.join("line")
.attr("class", "link")
.attr("stroke", "var(--g-link)")
.attr("stroke-width", 2)
.attr("data-source", d => d.source.id)
.attr("data-target", d => d.target.id)
// svg groups
const graphNode = svg.append("g")
.selectAll("g")
.data(data.nodes)
.enter().append("g")
// draw individual nodes
const node = graphNode.append("circle")
.attr("class", "node")
.attr("id", (d) => d.id)
.attr("r", (d) => {
const numOut = index.links[d.id]?.length || 0
const numIn = index.backlinks[d.id]?.length || 0
return 3 + (numOut + numIn) / 4
})
.attr("fill", color)
.style("cursor", "pointer")
.on("click", (_, d) => {
window.location.href = baseUrl + '/' + decodeURI(d.id).replace(/\s+/g, '-')
})
.on("mouseover", function (_, d) {
d3.selectAll(".node")
.transition()
.duration(100)
.attr("fill", "var(--g-node-inactive)")
const neighbours = parseIdsFromLinks([...(index.links[d.id] || []), ...(index.backlinks[d.id] || [])])
const neighbourNodes = d3.selectAll(".node").filter(d => neighbours.includes(d.id))
const currentId = d.id
const linkNodes = d3.selectAll(".link").filter(d => d.source.id === currentId || d.target.id === currentId)
// highlight neighbour nodes
neighbourNodes
.transition()
.duration(200)
.attr("fill", color)
// highlight links
linkNodes
.transition()
.duration(200)
.attr("stroke", "var(--g-link-active)")
// show text for self
d3.select(this.parentNode)
.select("text")
.raise()
.transition()
.duration(200)
.style("opacity", 1)
}).on("mouseleave", function (_,d) {
d3.selectAll(".node")
.transition()
.duration(200)
.attr("fill", color)
const currentId = d.id
const linkNodes = d3.selectAll(".link").filter(d => d.source.id === currentId || d.target.id === currentId)
linkNodes
.transition()
.duration(200)
.attr("stroke", "var(--g-link)")
d3.select(this.parentNode)
.select("text")
.transition()
.duration(200)
.style("opacity", 0)
})
.call(drag(simulation));
// draw labels
const labels = graphNode.append("text")
.attr("dx", 12)
.attr("dy", ".35em")
.text((d) => content[decodeURI(d.id).replace(/\s+/g, '-')]?.title || "Untitled")
.style("opacity", 0)
.style("pointer-events", "none")
.call(drag(simulation));
// set panning
if (enableZoom) {
svg.call(d3.zoom()
.extent([[0, 0], [width, height]])
.scaleExtent([0.25, 4])
.on("zoom", ({transform}) => {
link.attr("transform", transform);
node.attr("transform", transform);
labels.attr("transform", transform);
}));
}
// progress the simulation
simulation.on("tick", () => {
link
.attr("x1", d => d.source.x)
.attr("y1", d => d.source.y)
.attr("x2", d => d.target.x)
.attr("y2", d => d.target.y)
node
.attr("cx", d => d.x)
.attr("cy", d => d.y)
labels
.attr("x", d => d.x)
.attr("y", d => d.y)
});
}