react-native-ui-lib/src/utils/textUtils.js

<p align="center"> <img src="https://user-images.githubusercontent.com/1780255/105469025-56759000-5ca0-11eb-993d-3568c1fd54f4.png" height="250px" style="display:block"/> </p> <p align="center">UI Toolset & Components Library for React Native</p> <p a

import { isEmpty, toLower } from 'lodash';

function getPartsByHighlight(targetString = '', highlightString) {
  if (typeof highlightString === 'string') {
    if (isEmpty(highlightString.trim())) {
      return [{
        string: targetString,
        shouldHighlight: false
      }];
    }

    return getTextPartsByHighlight(targetString, highlightString);
  } else {
    return getArrayPartsByHighlight(targetString, highlightString);
  }
}

function getTextPartsByHighlight(targetString = '', highlightString = '') {
  if (highlightString === '') {
    return [{
      string: targetString,
      shouldHighlight: false
    }];
  }

  const textParts = [];
  let highlightIndex;

  do {
    highlightIndex = targetString.toLowerCase().indexOf(highlightString.toLowerCase());

    if (highlightIndex !== -1) {
      if (highlightIndex > 0) {
        textParts.push({
          string: targetString.substring(0, highlightIndex),
          shouldHighlight: false
        });
      }

      textParts.push({
        string: targetString.substr(highlightIndex, highlightString.length),
        shouldHighlight: true
      });
      targetString = targetString.substr(highlightIndex + highlightString.length);
    } else {
      textParts.push({
        string: targetString,
        shouldHighlight: false
      });
    }
  } while (highlightIndex !== -1 && targetString.length > 0);

  return textParts;
}

function getArrayPartsByHighlight(targetString = '', highlightString = ['']) {
  const target = toLower(targetString);
  const indices = [];
  let index = 0;
  let lastWordLength = 0;

  for (let j = 0; j < highlightString.length; j++) {
    const word = toLower(highlightString[j]);

    if (word.length === 0) {
      break;
    }

    const targetSuffix = target.substring(index + lastWordLength);
    const i = targetSuffix.indexOf(word);

    if (i >= 0) {
      const newIndex = index + lastWordLength + i;
      indices.push({
        start: index + lastWordLength + i,
        end: index + lastWordLength + i + word.length
      });
      index = newIndex;
      lastWordLength = word.length;
    } else {
      break;
    }
  }

  const textParts = [];

  for (let k = 0; k < indices.length; k++) {
    if (k === 0 && indices[k].start !== 0) {
      textParts.push({
        string: targetString.substring(0, indices[k].start),
        shouldHighlight: false
      });
    }

    textParts.push({
      string: targetString.substring(indices[k].start, indices[k].end),
      shouldHighlight: true
    });

    if (indices[k].end < targetString.length) {
      if (k === indices.length - 1) {
        textParts.push({
          string: targetString.substring(indices[k].end),
          shouldHighlight: false
        });
      } else {
        textParts.push({
          string: targetString.substring(indices[k].end, indices[k + 1].start),
          shouldHighlight: false
        });
      }
    }
  }

  if (textParts.length === 0) {
    textParts.push({
      string: targetString,
      shouldHighlight: false
    });
  }

  return textParts;
}

export { getPartsByHighlight, getTextPartsByHighlight, getArrayPartsByHighlight };