context

What the application knows that the rows do not — the user’s role, today’s prices — handed to the grid’s callbacks.

Type	unknown
Default	not set
Live update (update())	Yes
Angular	the [context] input
<dz-grid>	the settings property: el.settings = { context: … }
Declared in	packages/dom/src/settings.ts

What it does

Any value, which the grid never reads: it hands it on. The column options editable, validate, tooltip and an editor’s options get it as an argument; so do rowClass, cellClass, every part, the selection’s canSelect and the export’s canExport. One rule can then say « a manager may edit this column » without a closure over global state.

A new value is a new identity: give a new object, not the same one changed. With update({ context }), what depends on it is asked again — the rows’ classes, which cells may be edited.

Example

TypeScript

import { createGrid } from '@dzgrid/dom';
import { EN } from '@dzgrid/dom/locales/en';

type Shift = { id: string; nurse: string; ward: string };
type Ctx = { role: 'manager' | 'staff' };

const isManager = (context: unknown) => (context as Ctx).role === 'manager';

const grid = createGrid<Shift>(document.getElementById('shifts')!, {
  rows: [{ id: 's1', nurse: 'A. Moreau', ward: 'North' }],
  columns: [
    { id: 'nurse', header: 'Nurse' },
    { id: 'ward', header: 'Ward', editable: (_row, context) => isManager(context) },
  ],
  getRowId: (s) => s.id,
  messages: EN,
  context: { role: 'staff' } satisfies Ctx,
});

grid.update({ context: { role: 'manager' } satisfies Ctx });   // the ward column's rule now says yes

Angular

import { Component, signal } from '@angular/core';
import { DzGrid, type DzgColumnOrGroup } from '@dzgrid/angular';
import { EN } from '@dzgrid/dom/locales/en';

type Shift = { id: string; nurse: string; ward: string };
type Ctx = { role: 'manager' | 'staff' };

@Component({
  selector: 'app-shifts',
  imports: [DzGrid],
  template: `<dz-grid [rows]="rows" [columns]="columns" [getRowId]="rowId" [messages]="messages" [context]="context()" />`,
})
export class Shifts {
  readonly context = signal<Ctx>({ role: 'staff' });
  readonly rows: Shift[] = [{ id: 's1', nurse: 'A. Moreau', ward: 'North' }];
  readonly columns: DzgColumnOrGroup<Shift>[] = [
    { id: 'nurse', header: 'Nurse' },
    { id: 'ward', header: 'Ward', editable: (_row, context) => (context as Ctx).role === 'manager' },
  ];
  readonly rowId = (s: Shift) => s.id;
  readonly messages = EN;
}

Web Component

import '@dzgrid/element/define';
import type { DzGridElement } from '@dzgrid/element';
import { EN } from '@dzgrid/dom/locales/en';

type Shift = { id: string; nurse: string; ward: string };
type Ctx = { role: 'manager' | 'staff' };

const grid = document.querySelector<DzGridElement<Shift>>('dz-grid')!;
grid.columns = [
  { id: 'nurse', header: 'Nurse' },
  { id: 'ward', header: 'Ward', editable: (_row, context) => (context as Ctx).role === 'manager' },
];
grid.getRowId = (s) => s.id;
grid.messages = EN;
grid.settings = { context: { role: 'staff' } satisfies Ctx };
grid.rows = [{ id: 's1', nurse: 'A. Moreau', ward: 'North' }];

Editing a cell needs the edit features: see Editing.

See also

• rowClass — classes from the row and the context.
• Editing — editable and validate.