Languages support

[wojciechczerniak]

Description

The only small change proposed here is to add language name and language code.

• Add language code
• If the specified language is not found, fallback to default, English.
• If a function is not translated it cannot be used. Return error as for unknown formula.
• Add test for language files that compare language.functions keys with registeredPlugins keys
• Language should be set as language code in Config Global settings #58
  

  hyperformula/src/Config.ts

  Line 41 in 37c1d1d

  language: enGB,

Language definition

const lang: LanguageDefinition = {
  languageCode: 'pl-PL',
  errors: {
    DIV_BY_ZERO: '#DZIEL/0!',
    NAME: '#NAZWA?',
    VALUE: '#ARG!',
    NUM: '#LICZBA!',
    NA: '#N/A',
    CYCLE: '#CYKL!',
    REF: '#ADR!',
  },
  interface: {
    NEW_SHEET_PREFIX: 'Arkusz'
  },
  functions: {
    'SUM': 'SUMA',
    'ADD': 'DODAJ',
    // ... more functions
  },
}

API proposal

public static registerLanguage(lang: LanguageDefinition): void;
public static getLanguage(name: string): LanguageDefinition;
public static getLanguages(): string[]; // ['pl-PL', 'en-GB', ...]

[izulin]

To be remembered -- after language rework, we should add a sanity check in config initialization (see #146 )

[izulin]

from #260 : "we could introduce a method getTranslation('interface.NEW_SHEET_PREFIX') to be sure the getter is unit tested correctly and we have fallbacks in place.

Right now I see here possible three null exceptions"

[wojciechczerniak]

Unfortunately, this is not done yet. Please, see the review: #263 (review) for details

[wojciechczerniak]

Done in #263 and #287