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Diffstat (limited to 'packages/merchant-backoffice-ui/src/components/form/useField.tsx')
-rw-r--r-- | packages/merchant-backoffice-ui/src/components/form/useField.tsx | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/packages/merchant-backoffice-ui/src/components/form/useField.tsx b/packages/merchant-backoffice-ui/src/components/form/useField.tsx new file mode 100644 index 000000000..8479d7ad8 --- /dev/null +++ b/packages/merchant-backoffice-ui/src/components/form/useField.tsx @@ -0,0 +1,86 @@ +/* + This file is part of GNU Taler + (C) 2021 Taler Systems S.A. + + GNU Taler is free software; you can redistribute it and/or modify it under the + terms of the GNU General Public License as published by the Free Software + Foundation; either version 3, or (at your option) any later version. + + GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY + WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR + A PARTICULAR PURPOSE. See the GNU General Public License for more details. + + You should have received a copy of the GNU General Public License along with + GNU Taler; see the file COPYING. If not, see <http://www.gnu.org/licenses/> + */ + +/** +* +* @author Sebastian Javier Marchano (sebasjm) +*/ + +import { ComponentChildren, VNode } from "preact"; +import { useFormContext } from "./FormProvider"; + +interface Use<V> { + error?: string; + required: boolean; + value: any; + initial: any; + onChange: (v: V) => void; + toStr: (f: V | undefined) => string; + fromStr: (v: string) => V +} + +export function useField<T>(name: keyof T): Use<T[typeof name]> { + const { errors, object, initialObject, toStr, fromStr, valueHandler } = useFormContext<T>() + type P = typeof name + type V = T[P] + + const updateField = (field: P) => (value: V): void => { + return valueHandler((prev) => { + return setValueDeeper(prev, String(field).split('.'), value) + }) + } + + const defaultToString = ((f?: V): string => String(!f ? '' : f)) + const defaultFromString = ((v: string): V => v as any) + const value = readField(object, String(name)) + const initial = readField(initialObject, String(name)) + const isDirty = value !== initial + const hasError = readField(errors, String(name)) + return { + error: isDirty ? hasError : undefined, + required: !isDirty && hasError, + value, + initial, + onChange: updateField(name) as any, + toStr: toStr[name] ? toStr[name]! : defaultToString, + fromStr: fromStr[name] ? fromStr[name]! : defaultFromString, + } +} +/** + * read the field of an object an support accessing it using '.' + * + * @param object + * @param name + * @returns + */ +const readField = (object: any, name: string) => { + return name.split('.').reduce((prev, current) => prev && prev[current], object) +} + +const setValueDeeper = (object: any, names: string[], value: any): any => { + if (names.length === 0) return value + const [head, ...rest] = names + return { ...object, [head]: setValueDeeper(object[head] || {}, rest, value) } +} + +export interface InputProps<T> { + name: T; + label: ComponentChildren; + placeholder?: string; + tooltip?: ComponentChildren; + readonly?: boolean; + help?: ComponentChildren; +}
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