plane/web/components/issues/issue-layouts/roots/project-layout-root.tsx

import React from "react";
import { useRouter } from "next/router";
import { observer } from "mobx-react-lite";
import useSWR from "swr";
// mobx store
import { useMobxStore } from "lib/mobx/store-provider";
// components
import {
  ListLayout,
  CalendarLayout,
  GanttLayout,
  KanBanLayout,
  ProjectAppliedFiltersRoot,
  ProjectSpreadsheetLayout,
  ProjectEmptyState,
} from "components/issues";
import { Spinner } from "@plane/ui";

export const ProjectLayoutRoot: React.FC = observer(() => {
  const router = useRouter();
  const { workspaceSlug, projectId } = router.query;

  const { issue: issueStore, issueFilter: issueFilterStore } = useMobxStore();

  useSWR(workspaceSlug && projectId ? `PROJECT_FILTERS_AND_ISSUES_${projectId.toString()}` : null, async () => {
    if (workspaceSlug && projectId) {
      await issueFilterStore.fetchUserProjectFilters(workspaceSlug.toString(), projectId.toString());
      await issueStore.fetchIssues(workspaceSlug.toString(), projectId.toString());
    }
  });

  const activeLayout = issueFilterStore.userDisplayFilters.layout;

  const issueCount = issueStore.getIssuesCount;

  if (!issueStore.getIssues)
    return (
      <div className="h-full w-full grid place-items-center">
        <Spinner />
      </div>
    );

  return (
    <div className="relative w-full h-full flex flex-col overflow-hidden">
      <ProjectAppliedFiltersRoot />
      {(activeLayout === "list" || activeLayout === "spreadsheet") && issueCount === 0 ? (
        <ProjectEmptyState />
      ) : (
        <div className="w-full h-full overflow-auto">
          {activeLayout === "list" ? (
            <ListLayout />
          ) : activeLayout === "kanban" ? (
            <KanBanLayout />
          ) : activeLayout === "calendar" ? (
            <CalendarLayout />
          ) : activeLayout === "gantt_chart" ? (
            <GanttLayout />
          ) : activeLayout === "spreadsheet" ? (
            <ProjectSpreadsheetLayout />
          ) : null}
        </div>
      )}
    </div>
  );
});