i18next/i18next

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src/Interpolator.js

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import * as utils from './utils.js';
import baseLogger from './logger.js';

class Interpolator {
  constructor(options = {}) {
    this.logger = baseLogger.create('interpolator');

    this.options = options;
    this.format = (options.interpolation && options.interpolation.format) || ((value) => value);
    this.init(options);
  }

  /* eslint no-param-reassign: 0 */
  init(options = {}) {
    if (!options.interpolation) options.interpolation = { escapeValue: true };

    const iOpts = options.interpolation;

    this.escape = iOpts.escape !== undefined ? iOpts.escape : utils.escape;
    this.escapeValue = iOpts.escapeValue !== undefined ? iOpts.escapeValue : true;
    this.useRawValueToEscape =
      iOpts.useRawValueToEscape !== undefined ? iOpts.useRawValueToEscape : false;

    this.prefix = iOpts.prefix ? utils.regexEscape(iOpts.prefix) : iOpts.prefixEscaped || '{{';
    this.suffix = iOpts.suffix ? utils.regexEscape(iOpts.suffix) : iOpts.suffixEscaped || '}}';

    this.formatSeparator = iOpts.formatSeparator
      ? iOpts.formatSeparator
      : iOpts.formatSeparator || ',';

    this.unescapePrefix = iOpts.unescapeSuffix ? '' : iOpts.unescapePrefix || '-';
    this.unescapeSuffix = this.unescapePrefix ? '' : iOpts.unescapeSuffix || '';

    this.nestingPrefix = iOpts.nestingPrefix
      ? utils.regexEscape(iOpts.nestingPrefix)
      : iOpts.nestingPrefixEscaped || utils.regexEscape('$t(');
    this.nestingSuffix = iOpts.nestingSuffix
      ? utils.regexEscape(iOpts.nestingSuffix)
      : iOpts.nestingSuffixEscaped || utils.regexEscape(')');

    this.nestingOptionsSeparator = iOpts.nestingOptionsSeparator
      ? iOpts.nestingOptionsSeparator
      : iOpts.nestingOptionsSeparator || ',';

    this.maxReplaces = iOpts.maxReplaces ? iOpts.maxReplaces : 1000;

    this.alwaysFormat = iOpts.alwaysFormat !== undefined ? iOpts.alwaysFormat : false;

    // the regexp
    this.resetRegExp();
  }

  reset() {
    if (this.options) this.init(this.options);
  }

  resetRegExp() {
    // the regexp
    const regexpStr = `${this.prefix}(.+?)${this.suffix}`;
    this.regexp = new RegExp(regexpStr, 'g');

    const regexpUnescapeStr = `${this.prefix}${this.unescapePrefix}(.+?)${this.unescapeSuffix}${this.suffix}`;
    this.regexpUnescape = new RegExp(regexpUnescapeStr, 'g');

    const nestingRegexpStr = `${this.nestingPrefix}(.+?)${this.nestingSuffix}`;
    this.nestingRegexp = new RegExp(nestingRegexpStr, 'g');
  }

  interpolate(str, data, lng, options) {
    let match;
    let value;
    let replaces;

    const defaultData =
      (this.options && this.options.interpolation && this.options.interpolation.defaultVariables) ||
      {};

    function regexSafe(val) {
      return val.replace(/\$/g, '$$$$');
    }

    const handleFormat = (key) => {
      if (key.indexOf(this.formatSeparator) < 0) {
        const path = utils.getPathWithDefaults(data, defaultData, key);
        return this.alwaysFormat
          ? this.format(path, undefined, lng, { ...options, ...data, interpolationkey: key })
          : path;
      }

      const p = key.split(this.formatSeparator);
      const k = p.shift().trim();
      const f = p.join(this.formatSeparator).trim();

      return this.format(utils.getPathWithDefaults(data, defaultData, k), f, lng, {
        ...options,
        ...data,
        interpolationkey: k,
      });
    };

    this.resetRegExp();

    const missingInterpolationHandler =
      (options && options.missingInterpolationHandler) || this.options.missingInterpolationHandler;

    const skipOnVariables =
      options && options.interpolation && options.interpolation.skipOnVariables !== undefined
        ? options.interpolation.skipOnVariables
        : this.options.interpolation.skipOnVariables;

    const todos = [
      {
        // unescape if has unescapePrefix/Suffix
        regex: this.regexpUnescape,
        safeValue: (val) => regexSafe(val),
      },
      {
        // regular escape on demand
        regex: this.regexp,
        safeValue: (val) => (this.escapeValue ? regexSafe(this.escape(val)) : regexSafe(val)),
      },
    ];
    todos.forEach((todo) => {
      replaces = 0;
      /* eslint no-cond-assign: 0 */
      while ((match = todo.regex.exec(str))) {
        const matchedVar = match[1].trim();
        value = handleFormat(matchedVar);
        if (value === undefined) {
          if (typeof missingInterpolationHandler === 'function') {
            const temp = missingInterpolationHandler(str, match, options);
            value = typeof temp === 'string' ? temp : '';
          } else if (options && options.hasOwnProperty(matchedVar)) {
            value = ''; // undefined becomes empty string
          } else if (skipOnVariables) {
            value = match[0];
            continue; // this makes sure it continues to detect others
          } else {
            this.logger.warn(`missed to pass in variable ${matchedVar} for interpolating ${str}`);
            value = '';
          }
        } else if (typeof value !== 'string' && !this.useRawValueToEscape) {
          value = utils.makeString(value);
        }
        const safeValue = todo.safeValue(value);
        str = str.replace(match[0], safeValue);
        if (skipOnVariables) {
          todo.regex.lastIndex += safeValue.length;
          todo.regex.lastIndex -= match[0].length;
        } else {
          todo.regex.lastIndex = 0;
        }
        replaces++;
        if (replaces >= this.maxReplaces) {
          break;
        }
      }
    });
    return str;
  }

  nest(str, fc, options = {}) {
    let match;
    let value;

    let clonedOptions = { ...options };
    clonedOptions.applyPostProcessor = false; // avoid post processing on nested lookup
    delete clonedOptions.defaultValue; // assert we do not get a endless loop on interpolating defaultValue again and again

    // if value is something like "myKey": "lorem $(anotherKey, { "count": {{aValueInOptions}} })"
    function handleHasOptions(key, inheritedOptions) {
      const sep = this.nestingOptionsSeparator;
      if (key.indexOf(sep) < 0) return key;

      const c = key.split(new RegExp(`${sep}[ ]*{`));

      let optionsString = `{${c[1]}`;
      key = c[0];
      optionsString = this.interpolate(optionsString, clonedOptions);
      optionsString = optionsString.replace(/'/g, '"');

      try {
        clonedOptions = JSON.parse(optionsString);

        if (inheritedOptions) clonedOptions = { ...inheritedOptions, ...clonedOptions };
      } catch (e) {
        this.logger.warn(`failed parsing options string in nesting for key ${key}`, e);
        return `${key}${sep}${optionsString}`;
      }

      // assert we do not get a endless loop on interpolating defaultValue again and again
      delete clonedOptions.defaultValue;
      return key;
    }

    // regular escape on demand
    while ((match = this.nestingRegexp.exec(str))) {
      let formatters = [];

      /**
       * If there is more than one parameter (contains the format separator). E.g.:
       *   - t(a, b)
       *   - t(a, b, c)
       *
       * And those parameters are not dynamic values (parameters do not include curly braces). E.g.:
       *   - Not t(a, { "key": "{{variable}}" })
       *   - Not t(a, b, {"keyA": "valueA", "keyB": "valueB"})
       */
      let doReduce = false;
      if (match[0].indexOf(this.formatSeparator) !== -1 && !/{.*}/.test(match[1])) {
        const r = match[1].split(this.formatSeparator).map((elem) => elem.trim());
        match[1] = r.shift();
        formatters = r;
        doReduce = true;
      }

      value = fc(handleHasOptions.call(this, match[1].trim(), clonedOptions), clonedOptions);

      // is only the nesting key (key1 = '$(key2)') return the value without stringify
      if (value && match[0] === str && typeof value !== 'string') return value;

      // no string to include or empty
      if (typeof value !== 'string') value = utils.makeString(value);
      if (!value) {
        this.logger.warn(`missed to resolve ${match[1]} for nesting ${str}`);
        value = '';
      }

      if (doReduce) {
        value = formatters.reduce(
          /* eslint-disable-line no-loop-func:0 */
          (v, f) =>
            this.format(v, f, options.lng, { ...options, interpolationkey: match[1].trim() }),
          value.trim(),
        );
      }

      // Nested keys should not be escaped by default #854
      // value = this.escapeValue ? regexSafe(utils.escape(value)) : regexSafe(value);
      str = str.replace(match[0], value);
      this.regexp.lastIndex = 0;
    }
    return str;
  }
}

export default Interpolator;