mr-excel/src/functions/theme.ts

A versatile JavaScript library for effortlessly generating .xlsx files from input objects. Seamlessly create Excel spreadsheets with data, formatting, formulas, and more.

import {
  type Data,
  type ExcelTable,
  type Header,
  type Sheet,
  type ThemeOption,
} from "../data-model/excel-table";
import { generateContrastTextColor, hexToRgbNegative } from "../utils/color";
function titleCase(value: string): string {
  let result = "";
  if (value.indexOf("_") > 0) {
    //pass when, value not include lowercase
    if (value.replace(/[a-z]/g, "").length == value.length) {
      result = value
        .split(/_/)
        .reduce((re, cu) => {
          return re + cu.charAt(0) + cu.substring(1).toLowerCase() + " ";
        }, "")
        .trim();
    } else {
      result = value.replace(/_/g, " ").trim();
    }
  } else {
    result = value.replace(/([A-Z])/g, " $1").trim();
    result = result.charAt(0).toUpperCase() + result.substring(1).trim();
  }
  return result;
}
function createHeaderBaseOnObject(obj: Object, filterKeys: string[]): Header[] {
  let keys = Object.keys(obj).filter((v) => !filterKeys.includes(v));
  let init: Header[] = [];
  let headers: Header[] = keys.reduce((res, cu) => {
    res.push({
      label: cu,
      text: titleCase(cu),
    });
    return res;
  }, init);
  return headers;
}
const defaultColor: ThemeOption = {
  fileName: "MR-Excel",
  headerBackgroundColor: "#393E46",
  headerColor: "#EEEEEE",
  negativeColor: false,
  rowBackgroundColor: "#EEEEEE",
  rowColor: "#393E46",
  filterKeys: [],
};
export const themeGenerator = function (
  inputData: ExcelTable | Data[] | Data[][],
  option: ThemeOption = {
    ...defaultColor,
  }
): ExcelTable {
  let data: ExcelTable;
  if (typeof inputData == "object" && Array.isArray(inputData)) {
    if (inputData.length > 0) {
      if (Array.isArray(inputData[0])) {
        let sheet: Sheet[] = [];
        for (let index = 0; index < inputData.length; index++) {
          const element = inputData[index] as Data[];
          if (element.length > 0) {
            const headers = createHeaderBaseOnObject(
              element[0],
              Array.isArray(option.filterKeys) ? option.filterKeys : []
            );
            sheet.push({
              headers,
              data: element,
            });
          }
        }
        data = {
          sheet,
        };
      } else {
        if (inputData.length > 0) {
          const headers = createHeaderBaseOnObject(
            inputData[0],
            Array.isArray(option.filterKeys) ? option.filterKeys : []
          );
          data = {
            sheet: [
              {
                headers,
                data: inputData,
              },
            ],
          };
        } else {
          data = {
            sheet: [],
          };
        }
      }
    } else {
      data = {
        sheet: [],
      };
    }
  } else {
    data = inputData;
  }
  let headerColor =
    option && option.headerBackgroundColor
      ? option.headerBackgroundColor
      : defaultColor.headerBackgroundColor!;

  let rowColor =
    option && option.rowBackgroundColor
      ? option.rowBackgroundColor
      : defaultColor.rowBackgroundColor!;

  let headerColorText =
    option && option.negativeColor
      ? hexToRgbNegative(headerColor)
      : option && !!option.headerColor
      ? option.headerColor
      : generateContrastTextColor(headerColor);

  let rowColorText =
    option && option.negativeColor
      ? hexToRgbNegative(rowColor)
      : option && !!option.rowColor
      ? option.rowColor
      : generateContrastTextColor(rowColor);

  if (typeof data.styles == "undefined") {
    data.styles = {};
  }
  data.styles["themeStyleHeader"] = {
    backgroundColor: headerColor,
    color: headerColorText,
  };
  data.styles["themeStyleBody"] = {
    backgroundColor: rowColor,
    color: rowColorText,
  };
  const shLength = data.sheet.length;
  for (let index = 0; index < shLength; index++) {
    data.sheet[index].styleCellCondition = function (
      data,
      object,
      rowIndex,
      colIndex,
      fromHeader,
      styleKeys
    ) {
      if (fromHeader) {
        return "themeStyleHeader";
      } else {
        return "themeStyleBody";
      }
    };
  }

  if (typeof option?.fileName == "string") {
    data.fileName = option.fileName;
  }
  return data;
};

export const exportedForTesting = {
  titleCase,
  createHeaderBaseOnObject,
};