line-i18n/LocalizedStrings.ts

import { LanguageService } from "./LanguageService";
import { StringTypes } from "./StringTypes";

type LangInfo = { [id: string]: string };
type LangData = { [id: string]: LangInfo };
type LangObject = { [id: string]: LangData };

export class LocalizedStrings {
  private document: Document = document;

  constructor(
    private service: LanguageService,
    private i18nData: LangObject,
    private listenToChange = false
  ) {
    if (this.listenToChange) {
      service.registerLanguageChangeListener(() => {
        this.updateTagText();
      });
    }
  }

  getString(id: string, type: string): string {
    let i18nObj = this.i18nData[this.service.getLang()];
    if (!i18nObj) {
      console.warn(
        `Internal Error. The language set at ivprog.lang is not valid: ${this.service.getLang()}`
      );
      return this.getDefaultString(id, type);
    }
    if (!i18nObj[type]) {
      return this.getDefaultString(id, type);
    } else if (!i18nObj[type][id]) {
      return this.getDefaultString(id, type);
    } else {
      return i18nObj[type][id];
    }
  }

  private getDefaultString(id: string, type: string): string {
    let i18nObj = this.i18nData[this.service.getDefaultLang()];

    if (!i18nObj[type]) {
      return `{MISSING_I18N_TYPE_IDENTIFIER: ${type}}`;
    } else if (!i18nObj[type][id]) {
      return `{MISSING_I18N_IDENTIFIER: ${id}}`;
    } else {
      return i18nObj[type][id];
    }
  }

  getOR(): String {
    return this.getUI("string_join_or");
  }

  getError(id: string, context: [] = []) {
    const text = this.getString(id, StringTypes.ERROR);
    return this.processString(text, context);
  }

  getMessage(id: string, context: [] = []) {
    const text = this.getString(id, StringTypes.MESSAGE);
    return this.processString(text, context);
  }

  getUI(id: string, context: [] = []) {
    const text = this.getString(id, StringTypes.UI);
    return this.processString(text, context);
  }

  processString(text: string, context: []) {
    for (let i = 0; i < context.length; i++) {
      const v = context[i];
      text = text.replace("$" + i, v);
    }
    return text;
  }

  updateTagText(func: ((str: string | null) => string) | null = null): void {
    if (this.document !== null) {
      const list = this.document.querySelectorAll("data.i18n");
      list.forEach((node) => {
        if (func === null) {
          node.innerHTML = this.processTagTex(node.getAttribute("value"));
        } else {
          node.innerHTML = func(node.getAttribute("value"));
        }
      });
    }
  }

  processTagTex(text: string | null): string {
    if (text === null) {
      return "<Invalid i18n identifier>";
    }
    const opts = text.split(":");
    const type = opts[0].toLowerCase();
    const id = opts[1];
    if (StringTypes.ERROR === type) {
      return this.getError(id);
    } else if (StringTypes.MESSAGE === type) {
      return this.getMessage(id);
    } else if (StringTypes.UI === type) {
      return this.getUI(id);
    } else {
      console.warn(
        " A string has been passed to the i18n helper function that was not in the form type:id -> " +
          text
      );
      return this.getString(id, type);
    }
  }
}