@progress/kendo-data-query FilterDescriptor 运算符函数签名

Question

根据 the docs，FilterDescriptor 的 operator 属性可以是一个函数。

filterDescriptor.d.ts

/**
 * A basic filter expression. Usually a part of [`CompositeFilterDescriptor`]({% slug api_kendo-data-query_compositefilterdescriptor %}).
 *
 * For more information, refer to the [`filterBy`]({% slug api_kendo-data-query_filterby %}) method.
 */
export interface FilterDescriptor {
    /**
     * The field of the data item to which the filter operator is applied.
     */
    field?: string | Function;
    /**
     * The filter operator (comparison).
     *
     * The supported operators are:
     * * `"eq"` (equal to)
     * * `"neq"` (not equal to)
     * * `"isnull"` (is equal to null)
     * * `"isnotnull"` (is not equal to null)
     * * `"lt"` (less than)
     * * `"lte"` (less than or equal to)
     * * `"gt"` (greater than)
     * * `"gte"` (greater than or equal to)
     *
     * The following operators are supported for string fields only:
     * * `"startswith"`
     * * `"endswith"`
     * * `"contains"`
     * * `"doesnotcontain"`
     * * `"isempty"`
     * * `"isnotempty"`
     */
    operator: string | Function;
    /**
     * The value to which the field is compared. Has to be of the same type as the field.
     */
    value?: any;
    /**
     * Determines if the string comparison is case-insensitive.
     */
    ignoreCase?: boolean;
}

我在互联网上找不到任何关于 FilterDescriptor.operator 的函数签名的信息。当然，因为 Kendo 不是开源的，我不能简单地检查他们的代码。

Answer 1

通过一些日志记录，我明白了。

export interface FilterDescriptor {
  // ...
  operator: string | ((fieledValue: any, filterValue: any) => boolean);
}

因此，如果您有一个带有名称的对象列表，并且您想要创建一个匹配多个名称之一的过滤器（假设您不想为每个名称创建一个过滤器条目），您可以这样做：

const createFilterDesc = (options) => ({
  field: 'name',
  value: new Set(options),
  operator: (val, opts) => opts.has(val),
});