ag-grid-column-builder

ag-grid-column-builder

A typesafe builder for creating column definitions in ag-grid.

Ag-grid now supports types on the ColDef but its not implemented very well, with very little type safety.

This library uses the dot notation expressed in the field definition property to automatically provide the types for the column's other properties, and provide build-time breaks if the dot notation is no longer correct.

Install

    npm install ag-grid-column-builder

Features

• build errors when the field no longer matches the source object
• automatic typing of ColDef handlers, passing the value, data, node.data all correctly typed, helping to catch api type changes at build time, not runtime.
• accelerator for custom renderer components that only require a value property

Requirements

Requires @ag-grid-community/core to be installed.

Examples

type Person = { firstName : string, lastName: string, age: number  }

const definition = createColumns<Person>()
    // .add({ field: 'unknown' }) // ❌ no such path
    // .add({ field: 'age.something' }) // ❌ no such path
    .add({
        field: 'age',
        valueFormatter: ({ value, data }) => {
            // ^ value is number ✅
            // ^ data is Person ✅
            return param.value.toString()
        }
    })
    .build()

It supports deeply nested objects, and dot notation references to objects and arrays not just primitives:

enum Status = {
    Open,
    Closed
}

type Shop = {
    name: string,
    description?: string,
    contact: {
        person: Person,
        tel: string[]
    }
}

const definition = createColumns<Shop>()
    .add({ field: 'name' })
    .add({ 
        field: 'description', 
        valueFormatter: ({ value }) => {
            // ^ value is string | undefined ✅
            return value
        }
    }),
    .add({ 
        field: 'contact.person', 
        valueFormatter: ({ value }) => {
            // ^ value is Person ✅
            return `${value.firstName} ${value.lastName}`
        }
    })
    .add({ 
        field: 'contact.tel', 
        valueFormatter: ({ value }) => {
            // ^ value is string[] ✅
            return value.join(', ')
        }
    })
    .build()

Grouped columns and non-typed columns

const definition = createColumns<Shop>()
    .add({ field: 'name' })
    .addGroup({
        headerName: 'Contact',
        children: createColumns<Shop>()
            .add({field: 'contact.person', cellRenderer: PersonRender})
            .add({field: 'contact.tel', valueFormatter: ({ value }) => value.join(', ')})
    })
    .untypedAdd({ flex: 1 })
    .build()

Custom cellRenderers

const PersonRenderer = (params: { value : Person}) => { /* etc */ }

const definition = createColumns<Shop>()
    .add({ 
        field: 'contact', 
        cellRenderer: PersonRenderer // ✅ type safe. 
        // If  either the Shop definition changes, or the `PersonRenderer` it will give a build
        // error on this `cellRenderer`. 
    })
    .build()

If you're using nominal/branded types, it provides deeper type restrictions:

type TimeMicro = bigint & { ___micro: never }

const MicroSecondRenderer = (props: {value: TimeMicro }) => { 
    /* render in fractions of milliseconds */
    return (value / 1000).toFixed(3)
}

type TimerResults = {
    duration: bigint
    durationMicros: TimeMicro
}

const definition = createColumns<TimerResults>()
    .add({ 
        field: 'durationMicros', 
        cellRenderer: MicroSecondRenderer // ✅ correct type between the field property and the renderer
    })
    .add({ 
        field: 'duration', 
        cellRenderer: MicroSecondRenderer // ❌ incorrect type between the field property and the renderer
    })
    .build()

Typed parameters

This library/builder provides fully typed values for the following ColDef properties:

• field: This is a required field on add method. If this doesn't exist in the type, it will be caught in a build failure
• valueFormatter
• equals
• onCellValueChanged
• onCellClicked
• onCellDoubleClicked
• cellClass
• cellClassRules
• cellRenderer
• comparator

License

ag-grid-column-builder is licensed under the MIT License.