FilterModel

Defined in: api/node/typescript/models.ts:431 ↗

FilterModel provides a filtered view of rows from a source model, by applying a filter function to each row of the source model. Only rows for which the filter function returns true are visible in the FilterModel.

Note that the FilterModel does not automatically observe modifications made directly to the source model (for example calling ArrayModel.push or ArrayModel.splice on the underlying source model). After such a modification, call FilterModel.reset to re-apply the filter function and refresh the filtered view. Modifications made through FilterModel.setRowData are reflected automatically.

Calling FilterModel.setRowData while the cached mapping is stale (i.e. after the source model was mutated directly without a following FilterModel.reset) does not just return stale reads — it writes to whatever source row the stale mapping points at, which may no longer be the row the caller intended. Always call FilterModel.reset after a direct source mutation before calling FilterModel.setRowData again.

Example

const source = new ArrayModel([1, 2, 3, 4, 5, 6]);
const evenNumbers = new FilterModel(source, (x) => x % 2 === 0);

// prints 2, 4, 6
for (const x of evenNumbers) {
    console.log(x);
}

js

Extends

• Model<T>

Type Parameters

T

T

Constructors

Constructor

new FilterModel<T>(sourceModel, filterFunction): FilterModel<T>

Defined in: api/node/typescript/models.ts:445 ↗

Constructs a new FilterModel that provides a filtered view on the given sourceModel by applying filterFunction on each of its rows.

Parameters

sourceModel

Model<T>

the wrapped model.

filterFunction

(data) => boolean

returns true if a row should be visible in the FilterModel.

Returns

FilterModel<T>

Overrides

Model<T>.constructor

Properties

sourceModel

readonly sourceModel: Model<T>

Defined in: api/node/typescript/models.ts:435 ↗

The source model that this FilterModel filters rows from.

Methods

[iterator]()

[iterator](): Iterator<T>

Defined in: api/node/typescript/models.ts:196 ↗

Returns

Iterator<T>

Inherited from

Model.[iterator]

---

filter()

filter(filterFunction): FilterModel<T>

Defined in: api/node/typescript/models.ts:118 ↗

Returns a new Model that only contains the rows of this model for which filterFunction returns true.

Parameters

filterFunction

(data) => boolean

returns true if a row should be visible.

Returns

FilterModel<T>

a new FilterModel that wraps the current model.

Inherited from

Model.filter

---

insertRow()

insertRow(_index, _data): void

Defined in: api/node/typescript/models.ts:190 ↗

Implementations of this function must add a row at the specified index, pushing all next rows to the right.

Parameters

_index

number

index of the row to insert.

_data

T

new data item to store in a new row.

Returns

void

Inherited from

Model.insertRow

---

map()

map<U>(mapFunction): MapModel<T, U>

Defined in: api/node/typescript/models.ts:108 ↗

Returns a new Model where all elements are mapped by the function mapFunction.

Type Parameters

U

U

Parameters

mapFunction

(data) => U

maps the data from T to U.

Returns

MapModel<T, U>

a new MapModel that wraps the current model.

Inherited from

Model.map

---

pushRow()

pushRow(_data): void

Defined in: api/node/typescript/models.ts:168 ↗

Implementations of this function must add a line to the model with the provided data.

Parameters

_data

T

new data item to store in a new row.

Returns

void

Inherited from

Model.pushRow

---

removeRow()

removeRow(_index): void

Defined in: api/node/typescript/models.ts:178 ↗

Implementations of this function must remove the row at the specified index.

Parameters

_index

number

index of the row to remove.

Returns

void

Inherited from

Model.removeRow

---

reset()

reset(): void

Defined in: api/node/typescript/models.ts:520 ↗

Re-applies the filter function on each row of the source model and notifies the run-time that the filtered view has changed. Call this after modifying the source model directly, so that the filtered view reflects the current state of the source model.

Returns

void

---

reverse()

reverse(): ReverseModel<T>

Defined in: api/node/typescript/models.ts:137 ↗

Returns a new Model with the same rows as this model, in reverse order.

Returns

ReverseModel<T>

a new ReverseModel that wraps the current model.

Inherited from

Model.reverse

---

rowCount()

rowCount(): number

Defined in: api/node/typescript/models.ts:468 ↗

Returns the number of entries in the filtered model.

Returns

number

Overrides

Model.rowCount

---

rowData()

rowData(row): T | undefined

Defined in: api/node/typescript/models.ts:477 ↗

Returns the data at the specified row.

Parameters

row

number

index in range 0..(rowCount() - 1).

Returns

T | undefined

undefined if row is out of range otherwise the data.

Overrides

Model.rowData

---

setRowData()

setRowData(row, data): void

Defined in: api/node/typescript/models.ts:498 ↗

Stores the given data in the source model at the row that corresponds to the given filtered row index, then re-reads it from the source model to decide whether it still passes the filter, notifying either a row change or a row removal accordingly.

If the source model’s setRowData does not synchronously commit the value read back by rowData (for example a read-only model that ignores the write), the cached mapping may go out of sync; call FilterModel.reset in that case.

Parameters

row

number

index in range 0..(rowCount() - 1).

data

T

new data item to store on the given row index.

Returns

void

Overrides

Model.setRowData

---

sort()

sort(compareFunction): SortModel<T>

Defined in: api/node/typescript/models.ts:129 ↗

Returns a new Model with the same rows as this model, ordered according to compareFunction.

Parameters

compareFunction

(a, b) => number

compares two rows the same way the callback passed to Array.prototype.sort does.

Returns

SortModel<T>

a new SortModel that wraps the current model.

Inherited from

Model.sort

---

unfilteredRow()

unfilteredRow(filteredRow): number | undefined

Defined in: api/node/typescript/models.ts:531 ↗

Given a filteredRow index into this FilterModel, returns the corresponding row index in the source model.

Parameters

filteredRow

number

index in range 0..(rowCount() - 1).

Returns

number | undefined

undefined if filteredRow is out of range otherwise the source row index.