nocodb/packages/nc-gui/components/erd/View.vue

<script setup lang="ts">
import type { Edge, Node } from '@braks/vue-flow'
import { Background, Controls, VueFlow } from '@braks/vue-flow'
import { UITypes } from 'nocodb-sdk'
import dagre from 'dagre'
import TableNode from './TableNode.vue'
import RelationEdge from './RelationEdge.vue'

interface Props {
  tables: any[]
  config: {
    showPkAndFk: boolean
    showViews: boolean
  }
}

const { tables, config } = defineProps<Props>()

const { metasWithIdAsKey } = useMetas()

const initialNodes = ref<Pick<Node, 'id' | 'data' | 'type'>[]>([])
const nodes = ref<Node[]>([])
const edges = ref<Edge[]>([])

const dagreGraph = new dagre.graphlib.Graph()
dagreGraph.setDefaultEdgeLabel(() => ({}))

const populateInitialNodes = () => {
  tables.forEach((table) => {
    if (!table.id) return

    dagreGraph.setNode(table.id, { width: 250, height: 50 * metasWithIdAsKey.value[table.id].columns.length })

    initialNodes.value.push({
      id: table.id,
      data: { ...metasWithIdAsKey.value[table.id], showPkAndFk: config.showPkAndFk },
      type: 'custom',
    })
  })

  dagreGraph.setGraph({ rankdir: 'LR' })
}

const populateEdges = () => {
  const ltarColumns = tables.reduce((acc: any[], table) => {
    const meta = metasWithIdAsKey.value[table.id!]
    const columns = meta.columns.filter((column: any) => column.uidt === UITypes.LinkToAnotherRecord && column.system !== 1)

    columns.forEach((column: any) => {
      if (column.colOptions.type === 'hm') {
        acc.push(column)
      }

      if (column.colOptions.type === 'mm') {
        // Avoid duplicate mm connections
        const correspondingColumn = acc.find(
          (c) =>
            c.colOptions.type === 'mm' &&
            c.colOptions.fk_parent_column_id === column.colOptions.fk_child_column_id &&
            c.colOptions.fk_child_column_id === column.colOptions.fk_parent_column_id,
        )
        if (!correspondingColumn) {
          acc.push(column)
        }
      }
    })

    return acc
  }, [])

  edges.value = ltarColumns.map((column: any) => {
    const source = column.fk_model_id
    const target = column.colOptions.fk_related_model_id
    let sourceColumnId, targetColumnId

    if (column.colOptions.type === 'hm') {
      sourceColumnId = column.colOptions.fk_child_column_id
      targetColumnId = column.colOptions.fk_child_column_id
    }
    if (column.colOptions.type === 'mm') {
      sourceColumnId = column.colOptions.fk_parent_column_id
      targetColumnId = column.colOptions.fk_child_column_id
    }

    dagreGraph.setEdge(source, target)

    return {
      id: `e-${sourceColumnId}-${source}-${targetColumnId}-${target}`,
      source: `${source}`,
      target: `${target}`,
      sourceHandle: `s-${sourceColumnId}-${source}`,
      targetHandle: `d-${targetColumnId}-${target}`,
      type: 'custom',
      data: {
        column,
      },
    }
  })
}

const layoutNodes = () => {
  dagre.layout(dagreGraph)

  nodes.value = initialNodes.value.flatMap((node) => {
    const nodeWithPosition = dagreGraph.node(node.id)

    if (!nodeWithPosition) return []

    return [{ ...node, position: { x: nodeWithPosition.x, y: nodeWithPosition.y } } as Node]
  })
}

onBeforeMount(async () => {
  populateInitialNodes()
  populateEdges()
  layoutNodes()
})
</script>

<template>
  <VueFlow :nodes="nodes" :edges="edges" :fit-view-on-init="true" :elevate-edges-on-select="true">
    <Controls class="!left-auto right-2 !top-2 !bottom-auto" :show-fit-view="false" :show-interactive="false" />

    <template #node-custom="props">
      <TableNode :data="props.data" />
    </template>

    <template #edge-custom="props">
      <RelationEdge v-bind="props" />
    </template>
    <Background />
  </VueFlow>
</template>