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Application State And Persistence

Edit a task, save the project to browser memory, change it again, then load the saved snapshot. The transport is an in-memory example; wire your own backend for durable storage.

Source code
TypeScriptts
import { defineCustomElements } from '@revolist/revogrid/loader';
defineCustomElements();

import { defineGanttToolbar, GanttPlugin, type ProjectSnapshot } from '@revolist/gantt';
import { ExportExcelPlugin, RowSelectPlugin } from '@revolist/revogrid-pro';
import { currentTheme } from '../composables/useRandomData';
import {
  SHOWCASE_ASSIGNMENTS, SHOWCASE_BASELINES, SHOWCASE_COLUMNS_WITH_ROW_SELECT, SHOWCASE_DEPENDENCIES,
  SHOWCASE_RESOURCES, SHOWCASE_TOOLBAR_COLUMNS, STANDARD_CALENDAR,
} from './shared/gantt-project-data';
import { createProductionGanttConfig, createProductionTasks, createProductionPersistence, productionError, productionSourceRows } from './GanttProductionPatternsShared';
import './gantt-production-patterns.css';

export function load(parentSelector: string) {
  const parent = document.querySelector(parentSelector);
  if (!parent) return () => {};
  const root = document.createElement('section');
  const controls = document.createElement('div');
  const status = document.createElement('p');
  const toolbar = document.createElement('div');
  const grid = document.createElement('revo-grid');
  const persistence = createProductionPersistence();
  let readOnly = false;
  let localized = false;
  let large = false;
  let project: ProjectSnapshot | null = null;
  const applyConfig = () => { grid.gantt = createProductionGanttConfig(readOnly, localized, project); };
  const applyProject = () => {
    applyConfig();
    grid.ganttDependencies = project?.dependencies ?? (large ? [] : SHOWCASE_DEPENDENCIES);
    grid.ganttCalendars = project?.calendars ?? [STANDARD_CALENDAR];
    grid.ganttResources = project?.resources ?? SHOWCASE_RESOURCES;
    grid.ganttAssignments = project?.assignments ?? (large ? [] : SHOWCASE_ASSIGNMENTS);
    grid.ganttBaselines = project?.baselines ?? (large ? [] : SHOWCASE_BASELINES);
    grid.source = project ? productionSourceRows(project) : createProductionTasks(large);
  };
  const toggle = (label: string, update: (value: boolean) => void) => {
    const element = document.createElement('label');
    const input = document.createElement('input');
    input.type = 'checkbox';
    input.addEventListener('change', () => update(input.checked));
    element.append(input, document.createTextNode(label));
    return { element, input };
  };
  const run = async (action: () => unknown | Promise<unknown>) => {
    try { await action(); } catch (error) { status.textContent = productionError(error); }
  };
  const button = (label: string, action: () => unknown | Promise<unknown>) => {
    const element = document.createElement('button');
    element.type = 'button';
    element.textContent = label;
    element.addEventListener('click', () => { void run(action); });
    return element;
  };
  root.className = 'gantt-production-demo';
  controls.className = 'gantt-production-controls';
  status.className = 'gantt-production-status';
  status.setAttribute('role', 'status');
  status.textContent = 'Save and restore use browser memory only; no server is contacted.';
  toolbar.className = 'gantt-production-toolbar';
  grid.className = 'gantt-production-grid';
  grid.theme = currentTheme().isDark() ? 'darkCompact' : 'compact';
  grid.hideAttribution = true;
  grid.plugins = [GanttPlugin, ExportExcelPlugin, RowSelectPlugin];
  grid.rowSelect = { rowOrder: true };
  grid.columns = [...SHOWCASE_COLUMNS_WITH_ROW_SELECT];
  const largeToggle = toggle('750 tasks', (value) => { large = value; project = null; applyProject(); });
  const restore = button('Restore saved project', async () => {
    project = await persistence.load();
    large = false;
    largeToggle.input.checked = false;
    applyProject();
    status.textContent = 'Restored the saved project, including tasks and project collections.';
  });
  restore.disabled = true;
  const importLabel = document.createElement('label');
  importLabel.className = 'gantt-production-file';
  importLabel.textContent = 'Import JSON';
  const fileInput = document.createElement('input');
  fileInput.type = 'file';
  fileInput.accept = '.json,application/json';
  fileInput.setAttribute('aria-label', 'Import JSON');
  fileInput.addEventListener('change', async () => {
    const file = fileInput.files?.[0];
    if (file) await run(async () => {
      project = await persistence.importFile(file);
      large = false;
      largeToggle.input.checked = false;
      applyProject();
      status.textContent = `Imported ${project.tasks.length} tasks from ${file.name}.`;
    });
    fileInput.value = '';
  });
  importLabel.append(fileInput);
  controls.append(
    toggle('Read only', (value) => { readOnly = value; applyConfig(); }).element,
    toggle('Español dates', (value) => { localized = value; applyConfig(); }).element,
    largeToggle.element,
    importLabel,
    button('Export JSON', () => persistence.exportFile(grid)),
    button('Save in memory', async () => {
      await persistence.save(grid);
      restore.disabled = false;
      status.textContent = 'Saved the current edited project in browser memory.';
    }),
    restore,
    button('Print / PDF', () => persistence.print(grid)),
  );
  root.append(controls, status, toolbar, grid);
  parent.appendChild(root);
  applyProject();
  defineGanttToolbar(toolbar, { grid, columns: SHOWCASE_TOOLBAR_COLUMNS, controls: { baseline: true } });
  return () => { toolbar.textContent = ''; grid.remove(); root.remove(); };
}
Vuevue
<template>
  <section class="gantt-production-demo">
    <div class="gantt-production-controls">
      <label><input v-model="readOnly" type="checkbox" />Read only</label>
      <label><input v-model="localized" type="checkbox" />Español dates</label>
      <label><input v-model="large" type="checkbox" @change="project = null" />750 tasks</label>
      <label class="gantt-production-file">Import JSON<input type="file" accept=".json,application/json" aria-label="Import JSON" @change="importJson" /></label>
      <button type="button" @click="run(() => persistence.exportFile(getGrid()))">Export JSON</button>
      <button type="button" @click="save">Save in memory</button>
      <button type="button" :disabled="!hasSaved" @click="restore">Restore saved project</button>
      <button type="button" @click="run(() => persistence.print(getGrid()))">Print / PDF</button>
    </div>
    <p class="gantt-production-status" role="status">{{ status }}</p>
    <div ref="toolbarRef" class="gantt-production-toolbar"></div>
    <RevoGrid ref="gridRef" class="gantt-production-grid" hide-attribution :theme="isDark ? 'darkCompact' : 'compact'"
      :plugins="plugins" :row-select.prop="rowSelect" :source="tasks" :columns="columns" :gantt.prop="ganttConfig"
      :gantt-dependencies.prop="dependencies" :gantt-calendars.prop="calendars" :gantt-resources.prop="resources"
      :gantt-assignments.prop="assignments" :gantt-baselines.prop="baselines" />
  </section>
</template>

<script setup lang="ts">
import { computed, nextTick, onBeforeUnmount, onMounted, ref } from 'vue';
import RevoGrid from '@revolist/vue3-datagrid';
import { defineGanttToolbar, GanttPlugin, type ProjectSnapshot } from '@revolist/gantt';
import { ExportExcelPlugin, RowSelectPlugin } from '@revolist/revogrid-pro';
import { currentThemeVue } from '../composables/useRandomData';
import { SHOWCASE_ASSIGNMENTS, SHOWCASE_BASELINES, SHOWCASE_COLUMNS_WITH_ROW_SELECT, SHOWCASE_DEPENDENCIES, SHOWCASE_RESOURCES, SHOWCASE_TOOLBAR_COLUMNS, STANDARD_CALENDAR } from './shared/gantt-project-data';
import { createProductionGanttConfig, createProductionTasks, createProductionPersistence, productionError, productionSourceRows } from './GanttProductionPatternsShared';
import './gantt-production-patterns.css';
const { isDark } = currentThemeVue();
const plugins = [GanttPlugin, ExportExcelPlugin, RowSelectPlugin];
const rowSelect = { rowOrder: true };
const columns = SHOWCASE_COLUMNS_WITH_ROW_SELECT;
const readOnly = ref(false);
const localized = ref(false);
const large = ref(false);
const project = ref<ProjectSnapshot | null>(null);
const status = ref('Save and restore use browser memory only; no server is contacted.');
const hasSaved = ref(false);
const persistence = createProductionPersistence();
const tasks = computed(() => project.value ? productionSourceRows(project.value) : createProductionTasks(large.value));
const dependencies = computed(() => project.value?.dependencies ?? (large.value ? [] : SHOWCASE_DEPENDENCIES));
const calendars = computed(() => project.value?.calendars ?? [STANDARD_CALENDAR]);
const resources = computed(() => project.value?.resources ?? SHOWCASE_RESOURCES);
const assignments = computed(() => project.value?.assignments ?? (large.value ? [] : SHOWCASE_ASSIGNMENTS));
const baselines = computed(() => project.value?.baselines ?? (large.value ? [] : SHOWCASE_BASELINES));
const ganttConfig = computed(() => createProductionGanttConfig(readOnly.value, localized.value, project.value));
const gridRef = ref<InstanceType<typeof RevoGrid> | HTMLRevoGridElement | null>(null);
const toolbarRef = ref<HTMLElement | null>(null);
let frame = 0;
function getGrid(): HTMLRevoGridElement {
  const value = gridRef.value as (InstanceType<typeof RevoGrid> & { $el?: HTMLRevoGridElement }) | HTMLRevoGridElement | null;
  const grid = value && '$el' in value ? value.$el : value;
  if (!(grid instanceof HTMLElement)) throw new Error('The grid is still loading.');
  return grid as HTMLRevoGridElement;
}
async function run(action: () => unknown | Promise<unknown>) {
  try { await action(); } catch (error) { status.value = productionError(error); }
}
async function save() { await run(async () => { await persistence.save(getGrid()); hasSaved.value = true; status.value = 'Saved the current edited project in browser memory.'; }); }
async function restore() { await run(async () => { project.value = await persistence.load(); large.value = false; status.value = 'Restored the saved project, including tasks and project collections.'; }); }
async function importJson(event: Event) {
  const input = event.target as HTMLInputElement;
  const file = input.files?.[0];
  if (file) await run(async () => { project.value = await persistence.importFile(file); large.value = false; status.value = `Imported ${project.value.tasks.length} tasks from ${file.name}.`; });
  input.value = '';
}
function mountToolbar() {
  let grid: HTMLRevoGridElement;
  try { grid = getGrid(); } catch { frame = requestAnimationFrame(mountToolbar); return; }
  if (toolbarRef.value) defineGanttToolbar(toolbarRef.value, { grid, columns: SHOWCASE_TOOLBAR_COLUMNS, controls: { baseline: true } });
}
onMounted(async () => { await nextTick(); mountToolbar(); });
onBeforeUnmount(() => { cancelAnimationFrame(frame); if (toolbarRef.value) toolbarRef.value.textContent = ''; });
</script>
Reacttsx
import React, { useEffect, useMemo, useRef, useState } from 'react';
import { RevoGrid } from '@revolist/react-datagrid';
import { defineGanttToolbar, GanttPlugin, type ProjectSnapshot } from '@revolist/gantt';
import { ExportExcelPlugin, RowSelectPlugin } from '@revolist/revogrid-pro';
import { currentTheme } from '../composables/useRandomData';
import {
  SHOWCASE_ASSIGNMENTS, SHOWCASE_BASELINES, SHOWCASE_COLUMNS_WITH_ROW_SELECT, SHOWCASE_DEPENDENCIES,
  SHOWCASE_RESOURCES, SHOWCASE_TOOLBAR_COLUMNS, STANDARD_CALENDAR,
} from './shared/gantt-project-data';
import { createProductionGanttConfig, createProductionTasks, createProductionPersistence, productionError, productionSourceRows } from './GanttProductionPatternsShared';
import './gantt-production-patterns.css';

export default function GanttProductionPatterns() {
  const gridRef = useRef<HTMLRevoGridElement>(null);
  const toolbarRef = useRef<HTMLDivElement>(null);
  const [readOnly, setReadOnly] = useState(false);
  const [localized, setLocalized] = useState(false);
  const [large, setLarge] = useState(false);
  const [project, setProject] = useState<ProjectSnapshot | null>(null);
  const [status, setStatus] = useState('Save and restore use browser memory only; no server is contacted.');
  const [hasSaved, setHasSaved] = useState(false);
  const persistence = useMemo(() => createProductionPersistence(), []);
  const plugins = useMemo(() => [GanttPlugin, ExportExcelPlugin, RowSelectPlugin], []);
  const rowSelect = useMemo(() => ({ rowOrder: true }), []);
  const columns = useMemo(() => SHOWCASE_COLUMNS_WITH_ROW_SELECT, []);
  const tasks = useMemo(() => project ? productionSourceRows(project) : createProductionTasks(large), [project, large]);
  const gantt = useMemo(() => createProductionGanttConfig(readOnly, localized, project), [readOnly, localized, project]);
  const dependencies = useMemo(() => project?.dependencies ?? (large ? [] : SHOWCASE_DEPENDENCIES), [project, large]);
  const calendars = useMemo(() => project?.calendars ?? [STANDARD_CALENDAR], [project]);
  const resources = useMemo(() => project?.resources ?? SHOWCASE_RESOURCES, [project]);
  const assignments = useMemo(() => project?.assignments ?? (large ? [] : SHOWCASE_ASSIGNMENTS), [project, large]);
  const baselines = useMemo(() => project?.baselines ?? (large ? [] : SHOWCASE_BASELINES), [project, large]);
  function getGrid(): HTMLRevoGridElement {
    if (!gridRef.current) throw new Error('The grid is still loading.');
    return gridRef.current;
  }
  async function run(action: () => unknown | Promise<unknown>) {
    try { await action(); } catch (error) { setStatus(productionError(error)); }
  }
  async function save() {
    await run(async () => {
      await persistence.save(getGrid());
      setHasSaved(true);
      setStatus('Saved the current edited project in browser memory.');
    });
  }
  async function restore() {
    await run(async () => {
      setProject(await persistence.load());
      setLarge(false);
      setStatus('Restored the saved project, including tasks and project collections.');
    });
  }
  async function importJson(event: React.ChangeEvent<HTMLInputElement>) {
    const input = event.currentTarget;
    const file = input.files?.[0];
    if (file) await run(async () => {
      const imported = await persistence.importFile(file);
      setProject(imported);
      setLarge(false);
      setStatus(`Imported ${imported.tasks.length} tasks from ${file.name}.`);
    });
    input.value = '';
  }
  useEffect(() => {
    const toolbar = toolbarRef.current;
    if (!toolbar || !gridRef.current) return;
    defineGanttToolbar(toolbar, { grid: gridRef.current, columns: SHOWCASE_TOOLBAR_COLUMNS, controls: { baseline: true } });
    return () => { toolbar.textContent = ''; };
  }, []);
  return <section className="gantt-production-demo">
    <div className="gantt-production-controls">
      <label><input type="checkbox" checked={readOnly} onChange={(event) => setReadOnly(event.currentTarget.checked)} />Read only</label>
      <label><input type="checkbox" checked={localized} onChange={(event) => setLocalized(event.currentTarget.checked)} />Español dates</label>
      <label><input type="checkbox" checked={large} onChange={(event) => { setLarge(event.currentTarget.checked); setProject(null); }} />750 tasks</label>
      <label className="gantt-production-file">Import JSON<input type="file" accept=".json,application/json" aria-label="Import JSON" onChange={importJson} /></label>
      <button type="button" onClick={() => { void run(() => persistence.exportFile(getGrid())); }}>Export JSON</button>
      <button type="button" onClick={save}>Save in memory</button>
      <button type="button" disabled={!hasSaved} onClick={restore}>Restore saved project</button>
      <button type="button" onClick={() => { void run(() => persistence.print(getGrid())); }}>Print / PDF</button>
    </div>
    <p className="gantt-production-status" role="status">{status}</p>
    <div ref={toolbarRef} className="gantt-production-toolbar" />
    <RevoGrid ref={gridRef} className="gantt-production-grid" theme={currentTheme().isDark() ? 'darkCompact' : 'compact'} hideAttribution
      plugins={plugins} rowSelect={rowSelect} source={tasks} columns={columns} gantt={gantt}
      ganttDependencies={dependencies} ganttCalendars={calendars} ganttResources={resources}
      ganttAssignments={assignments} ganttBaselines={baselines} />
  </section>;
}
Angularts
import { ChangeDetectorRef, inject, AfterViewInit, Component, ElementRef, NO_ERRORS_SCHEMA, OnDestroy, ViewChild, ViewEncapsulation } from '@angular/core';
import { RevoGrid } from '@revolist/angular-datagrid';
import { defineGanttToolbar, GanttPlugin, type ProjectSnapshot } from '@revolist/gantt';
import { ExportExcelPlugin, RowSelectPlugin } from '@revolist/revogrid-pro';
import { currentTheme } from '../composables/useRandomData';
import { SHOWCASE_ASSIGNMENTS, SHOWCASE_BASELINES, SHOWCASE_COLUMNS_WITH_ROW_SELECT, SHOWCASE_DEPENDENCIES, SHOWCASE_RESOURCES, SHOWCASE_TOOLBAR_COLUMNS, STANDARD_CALENDAR } from './shared/gantt-project-data';
import { createProductionGanttConfig, createProductionTasks, createProductionPersistence, productionError, productionSourceRows } from './GanttProductionPatternsShared';

@Component({
  selector: 'gantt-production-patterns-grid', standalone: true, schemas: [NO_ERRORS_SCHEMA], imports: [RevoGrid],
  styleUrls: ['./gantt-production-patterns.css'], encapsulation: ViewEncapsulation.None,
  template: `<section class="gantt-production-demo">
    <div class="gantt-production-controls">
      <label><input type="checkbox" [checked]="readOnly" (change)="setReadOnly($any($event.target).checked)" />Read only</label>
      <label><input type="checkbox" [checked]="localized" (change)="setLocalized($any($event.target).checked)" />Español dates</label>
      <label><input type="checkbox" [checked]="large" (change)="setLarge($any($event.target).checked)" />750 tasks</label>
      <label class="gantt-production-file">Import JSON<input type="file" accept=".json,application/json" aria-label="Import JSON" (change)="importJson($event)" /></label>
      <button type="button" (click)="exportJson()">Export JSON</button>
      <button type="button" (click)="save()">Save in memory</button>
      <button type="button" [disabled]="!hasSaved" (click)="restore()">Restore saved project</button>
      <button type="button" (click)="print()">Print / PDF</button>
    </div>
    <p class="gantt-production-status" role="status">{{ status }}</p>
    <div #toolbar class="gantt-production-toolbar"></div>
    <revo-grid #grid class="gantt-production-grid" [theme]="theme" [hideAttribution]="true" [plugins]="plugins"
      [rowSelect]="rowSelect" [source]="tasks" [columns]="columns" [gantt]="ganttConfig" [ganttDependencies]="dependencies"
      [ganttCalendars]="calendars" [ganttResources]="resources" [ganttAssignments]="assignments" [ganttBaselines]="baselines"></revo-grid>
  </section>`,
})
export class GanttProductionPatternsGridComponent implements AfterViewInit, OnDestroy {
  private readonly changeDetector = inject(ChangeDetectorRef);
  @ViewChild('grid', { read: ElementRef }) gridRef!: ElementRef<HTMLRevoGridElement>;
  @ViewChild('toolbar', { read: ElementRef }) toolbarRef!: ElementRef<HTMLElement>;
  theme = currentTheme().isDark() ? 'darkCompact' : 'compact';
  plugins = [GanttPlugin, ExportExcelPlugin, RowSelectPlugin]; rowSelect = { rowOrder: true }; columns = SHOWCASE_COLUMNS_WITH_ROW_SELECT;
  calendars = [STANDARD_CALENDAR]; resources = [...SHOWCASE_RESOURCES]; assignments = [...SHOWCASE_ASSIGNMENTS]; baselines = [...SHOWCASE_BASELINES];
  readOnly = false; localized = false; large = false; tasks = createProductionTasks(); dependencies = SHOWCASE_DEPENDENCIES;
  project: ProjectSnapshot | null = null;
  status = 'Save and restore use browser memory only; no server is contacted.';
  hasSaved = false;
  private persistence = createProductionPersistence();
  ganttConfig = createProductionGanttConfig();
  private refresh() { this.ganttConfig = createProductionGanttConfig(this.readOnly, this.localized, this.project); }
  private refreshProject() {
    this.tasks = this.project ? productionSourceRows(this.project) : createProductionTasks(this.large);
    this.dependencies = [...(this.project?.dependencies ?? (this.large ? [] : SHOWCASE_DEPENDENCIES))];
    this.calendars = [...(this.project?.calendars ?? [STANDARD_CALENDAR])];
    this.resources = [...(this.project?.resources ?? SHOWCASE_RESOURCES)];
    this.assignments = [...(this.project?.assignments ?? (this.large ? [] : SHOWCASE_ASSIGNMENTS))];
    this.baselines = [...(this.project?.baselines ?? (this.large ? [] : SHOWCASE_BASELINES))];
    this.refresh();
  }
  private getGrid(): HTMLRevoGridElement {
    const grid = this.gridRef?.nativeElement;
    if (!grid) throw new Error('The grid is still loading.');
    return grid;
  }
  private async run(action: () => unknown | Promise<unknown>) {
    try { await action(); } catch (error) { this.status = productionError(error); }
    finally { this.changeDetector.markForCheck(); }
  }
  setReadOnly(value: boolean) { this.readOnly = value; this.refresh(); }
  setLocalized(value: boolean) { this.localized = value; this.refresh(); }
  setLarge(value: boolean) { this.large = value; this.project = null; this.refreshProject(); }
  exportJson() { return this.run(() => this.persistence.exportFile(this.getGrid())); }
  print() { return this.run(() => this.persistence.print(this.getGrid())); }
  save() {
    return this.run(async () => {
      await this.persistence.save(this.getGrid()); this.hasSaved = true;
      this.status = 'Saved the current edited project in browser memory.';
    });
  }
  restore() {
    return this.run(async () => {
      this.project = await this.persistence.load(); this.large = false; this.refreshProject();
      this.status = 'Restored the saved project, including tasks and project collections.';
    });
  }
  async importJson(event: Event) {
    const input = event.target as HTMLInputElement;
    const file = input.files?.[0];
    if (file) await this.run(async () => {
      this.project = await this.persistence.importFile(file); this.large = false; this.refreshProject();
      this.status = `Imported ${this.project.tasks.length} tasks from ${file.name}.`;
    });
    input.value = '';
  }
  ngAfterViewInit() { defineGanttToolbar(this.toolbarRef.nativeElement, { grid: this.gridRef.nativeElement, columns: SHOWCASE_TOOLBAR_COLUMNS, controls: { baseline: true } }); }
  ngOnDestroy() { if (this.toolbarRef?.nativeElement) this.toolbarRef.nativeElement.textContent = ''; }
}
Sharedts
import { exportProjectSnapshot, parseProjectSnapshotJson, type GanttPluginConfig, type GanttTaskSourceRow, type ISODateString, type ProjectSnapshot } from '@revolist/gantt';
import { getGanttScheduleSnapshot } from './recipes/current-schedule-snapshot';
import { ProjectSnapshotRestAdapter } from './recipes/rest-adapter';
import { printGanttContainer } from './recipes/print-pdf-recipe';
import {
  SHOWCASE_ASSIGNMENTS,
  SHOWCASE_BASELINES,
  SHOWCASE_DEPENDENCIES,
  SHOWCASE_GANTT_CONFIG,
  SHOWCASE_RESOURCES,
  SHOWCASE_TASKS,
  STANDARD_CALENDAR,
} from './shared/gantt-project-data';

export function createProductionGanttConfig(readOnly = false, localized = false, project?: ProjectSnapshot | null): GanttPluginConfig {
  return {
    ...SHOWCASE_GANTT_CONFIG,
    ...(project ? { id: project.id, name: project.name, version: project.version, currency: project.currency, timeZone: project.timeZone, primaryCalendarId: project.primaryCalendarId, updatedAt: project.updatedAt, durationSettings: project.durationSettings, calendars: project.calendars } : {}),
    allowTaskCreate: true,
    taskCreateRow: true,
    readOnly,
    labels: localized ? {
      taskMode: { auto: 'Automática', manual: 'Manual' },
      workflowStatus: { 'not-started': 'Sin iniciar', 'in-progress': 'En curso', done: 'Finalizada', blocked: 'Bloqueada' },
    } : undefined,
    dateFormats: localized ? {
      locale: 'es-ES',
      table: { dateStyle: 'medium' },
      tooltip: { dateStyle: 'long' },
    } : undefined,
    visuals: {
      ...SHOWCASE_GANTT_CONFIG.visuals,
      showBaseline: true,
      showTaskLabels: true,
      timeRanges: [{ id: 'release-window', startDate: '2026-02-16', endDate: '2026-02-20', label: 'Release window', color: '#8b5cf633' }],
      milestoneLines: [{ id: 'go-live', date: '2026-02-27', label: 'Go live', color: '#e11d48' }],
      taskMarkerHook: (task) => task.deadlineDate ? [{ id: `deadline-${task.id}`, date: task.deadlineDate, label: 'Deadline' }] : [],
      taskBarColorHook: ({ row }) => row.id === SHOWCASE_TASKS[1].id ? { barColor: '#64748b', className: 'gantt-production-locked' } : undefined,
      taskTooltipFields: ['startDate', 'endDate', 'duration', 'percentDone', 'assignees'],
    },
  } as GanttPluginConfig;
}

export function createProductionTasks(large = false): GanttTaskSourceRow[] {
  if (!large) {
    return SHOWCASE_TASKS.map((task, index) => ({ ...task, ...(index === 1 ? { locked: true } : {}) })) as GanttTaskSourceRow[];
  }

  return Array.from({ length: 750 }, (_, index) => {
    const day = 2 + (index % 20);
    return {
      id: `large-${index + 1}`,
      name: `Virtualized task ${index + 1}`,
      startDate: `2026-02-${String(day).padStart(2, '0')}` as ISODateString,
      duration: 1 + (index % 5),
      durationUnit: 'day',
      percentDone: (index * 7) % 101,
      taskMode: 'manual',
      locked: index % 17 === 0,
    } satisfies GanttTaskSourceRow;
  });
}

export function productionSourceRows(project: ProjectSnapshot): GanttTaskSourceRow[] {
  return project.tasks.map((task) => ({
    ...task,
    durationUnit: task.durationUnit ?? 'hour',
    percentDone: task.progressPercent,
    taskMode: task.manuallyScheduled ? 'manual' : 'auto',
  }));
}

export async function getProductionProject(grid: HTMLRevoGridElement): Promise<ProjectSnapshot> {
  return getGanttScheduleSnapshot(grid);
}

export function downloadProductionSnapshot(project: ProjectSnapshot): void {
  const href = URL.createObjectURL(new Blob([exportProjectSnapshot(project, { space: 2 })], { type: 'application/json' }));
  const link = document.createElement('a');
  link.href = href;
  link.download = 'gantt-project.json';
  link.click();
  setTimeout(() => URL.revokeObjectURL(href), 0);
}

/** A real REST recipe with an injected browser-memory transport; no server is contacted. */
export function createProductionPersistence() {
  let savedJson: string | undefined;
  const adapter = new ProjectSnapshotRestAdapter({
    url: '/example/project',
    fetchImpl: (async (_input, init) => {
      if (init?.method === 'PUT') {
        savedJson = String(init.body);
        return new Response(null, { status: 204 });
      }
      return new Response(savedJson ?? 'No saved project', { status: savedJson ? 200 : 404 });
    }) as typeof fetch,
  });
  return {
    save: async (grid: HTMLRevoGridElement) => adapter.save(await getProductionProject(grid)),
    load: () => adapter.load(),
    importFile: async (file: Pick<File, 'text'>): Promise<ProjectSnapshot> => {
      const parsed = parseProjectSnapshotJson(await file.text());
      if (parsed.ok === false) throw new Error(parsed.error);
      return parsed.project;
    },
    exportFile: async (grid: HTMLRevoGridElement) => downloadProductionSnapshot(await getProductionProject(grid)),
    print: (grid: HTMLRevoGridElement) => {
      const result = printGanttContainer(grid.parentElement, { cleanupDelayMs: 60_000, hideSelectors: ['.gantt-production-controls', '.gantt-production-status', '.gantt-production-toolbar', '.gantt-toolbar', '.rgContextMenu'], metadata: { title: grid.gantt?.name ?? 'Project schedule' } });
      if (!result.ok) throw new Error('The print preview could not be opened.');
    },
  };
}

export function productionError(error: unknown): string {
  return error instanceof Error ? error.message : 'The operation failed.';
}

Your application owns persisted project data. Gantt owns scheduling, validation, projection, and supported local mutations while the grid is mounted.

Keep these collections together as one logical project snapshot:

  • source: authored task rows.
  • ganttDependencies.
  • ganttCalendars.
  • ganttResources.
  • ganttAssignments.
  • ganttBaselines.
  • gantt: project metadata and behavior configuration.

When a server response or collaborative update arrives, replace affected arrays and assign a new gantt object when configuration changed. Do not mutate an existing array in place and expect framework or custom-element change detection to observe it.

function applyProject(snapshot: ProjectSnapshot) {
grid.gantt = { ...snapshot };
grid.ganttCalendars = [...snapshot.calendars];
grid.ganttDependencies = [...snapshot.dependencies];
grid.ganttResources = [...snapshot.resources];
grid.ganttAssignments = [...snapshot.assignments];
grid.ganttBaselines = [...snapshot.baselines];
grid.source = snapshot.tasks.map(toSourceRow);
}
  1. Listen for the Gantt before-change events when the application needs authorization or validation.
  2. Allow Gantt to commit supported local mutations.
  3. Read the current project through the GanttPlugin instance or the application state updated by your integration.
  4. Persist a complete snapshot or an application-defined patch.
  5. Replace the public collections with the canonical server result when the server normalizes data.

Use JSON project helpers for snapshots and integration recipes for REST, GraphQL, PostgreSQL, and Supabase-style persistence.

  • Use stable entity IDs across every collection.
  • Version project writes in your backend and reject stale updates.
  • Re-run scheduling after dependency, calendar, task, resource, or assignment updates.
  • Keep optimistic rollback data outside the rendered DOM.
  • Use gantt.readOnly while a project is locked or awaiting approval.

See Events And Methods for cancelable events and plugin access.