/*
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
*/
/**
* Translation helpers for React components and template literals.
*/
/**
* Imports
*/
import { ComponentChild, ComponentChildren, h, Fragment, VNode } from "preact";
import { useTranslationContext } from "../context/translation";
export function useTranslator() {
const ctx = useTranslationContext();
const jed = ctx.handler;
return function str(
stringSeq: TemplateStringsArray,
...values: any[]
): string {
const s = toI18nString(stringSeq);
if (!s) return s;
const tr = jed
.translate(s)
.ifPlural(1, s)
.fetch(...values);
return tr;
};
}
/**
* Convert template strings to a msgid
*/
function toI18nString(stringSeq: ReadonlyArray): string {
let s = "";
for (let i = 0; i < stringSeq.length; i++) {
s += stringSeq[i];
if (i < stringSeq.length - 1) s += `%${i + 1}$s`;
}
return s;
}
interface TranslateSwitchProps {
target: number;
children: ComponentChildren;
}
function stringifyChildren(children: ComponentChildren): string {
let n = 1;
const ss = (children instanceof Array ? children : [children]).map((c) => {
if (typeof c === "string") return c;
return `%${n++}$s`;
});
const s = ss.join("").replace(/ +/g, " ").trim();
return s;
}
interface TranslateProps {
children: ComponentChildren;
/**
* Component that the translated element should be wrapped in.
* Defaults to "div".
*/
wrap?: any;
/**
* Props to give to the wrapped component.
*/
wrapProps?: any;
}
function getTranslatedChildren(
translation: string,
children: ComponentChildren,
): ComponentChild[] {
const tr = translation.split(/%(\d+)\$s/);
const childArray = children instanceof Array ? children : [children];
// Merge consecutive string children.
const placeholderChildren = Array();
for (let i = 0; i < childArray.length; i++) {
const x = childArray[i];
if (x === undefined) continue;
else if (typeof x === "string") continue;
else placeholderChildren.push(x);
}
const result = Array();
for (let i = 0; i < tr.length; i++)
if (i % 2 == 0)
// Text
result.push(tr[i]);
else {
const childIdx = Number.parseInt(tr[i], 10) - 1;
result.push(placeholderChildren[childIdx]);
}
return result;
}
/**
* Translate text node children of this component.
* If a child component might produce a text node, it must be wrapped
* in a another non-text element.
*
* Example:
* ```
*
* Hello. Your score is
*
* ```
*/
export function Translate({ children }: TranslateProps): VNode {
const s = stringifyChildren(children);
const ctx = useTranslationContext();
const translation: string = ctx.handler.ngettext(s, s, 1);
const result = getTranslatedChildren(translation, children);
return {result};
}
/**
* Switch translation based on singular or plural based on the target prop.
* Should only contain TranslateSingular and TransplatePlural as children.
*
* Example:
* ```
*
* I have {n} apple.
* I have {n} apples.
*
* ```
*/
export function TranslateSwitch({ children, target }: TranslateSwitchProps) {
let singular: VNode | undefined;
let plural: VNode | undefined;
// const children = this.props.children;
if (children)
(children instanceof Array ? children : [children]).forEach(
(child: any) => {
if (child.type === TranslatePlural) plural = child;
if (child.type === TranslateSingular) singular = child;
},
);
if (!singular || !plural) {
console.error("translation not found");
return h("span", {}, ["translation not found"]);
}
singular.props.target = target;
plural.props.target = target;
// We're looking up the translation based on the
// singular, even if we must use the plural form.
return singular;
}
interface TranslationPluralProps {
children: ComponentChildren;
target: number;
}
/**
* See [[TranslateSwitch]].
*/
export function TranslatePlural({
children,
target,
}: TranslationPluralProps): VNode {
const s = stringifyChildren(children);
const ctx = useTranslationContext();
const translation = ctx.handler.ngettext(s, s, 1);
const result = getTranslatedChildren(translation, children);
return {result};
}
/**
* See [[TranslateSwitch]].
*/
export function TranslateSingular({
children,
target,
}: TranslationPluralProps): VNode {
const s = stringifyChildren(children);
const ctx = useTranslationContext();
const translation = ctx.handler.ngettext(s, s, target);
const result = getTranslatedChildren(translation, children);
return {result};
}