@exabytellc/utils/dist/data/_data.js

EB react utils to make everything a little easier!

import { handleTryCatch } from "../_helpers/handleError";
import { isFormData } from "../types";

/**
 * Converts a JavaScript object or array into a FormData instance.
 *
 * @param {Object|Array} data - The data to convert to FormData.
 * @returns {FormData} - The resulting FormData instance.
 */
export function toFormdata(data) {
  return handleTryCatch({
    n: "toFormdata",
    p: { data },
    e: () => {
      const fd = new FormData();
      _dataToFormdata(fd, data, ""); // No root key
      return fd;
    }
  });

  /**
   * Recursively converts data into FormData format.
   *
   * @param {FormData} fd - The FormData instance being populated.
   * @param {*} value - The value to process.
   * @param {string} parentKey - The key path in the FormData structure.
   */
  function _dataToFormdata(fd, value, parentKey) {
    if (value === null || value === undefined) {
      return; // Ignore null/undefined values
    }

    if (Array.isArray(value)) {
      // If the root is an array, avoid wrapping it inside a key
      value.forEach((val, i) => {
        _dataToFormdata(fd, val, `${parentKey ? parentKey + "[" + i + "]" : i}`);
      });
    } else if (typeof value === "object" && !(value instanceof File)) {
      // Handle nested objects
      for (const [key, val] of Object.entries(value)) {
        _dataToFormdata(fd, val, parentKey ? `${parentKey}[${key}]` : key);
      }
    } else if (value instanceof File) {
      // Append only valid files
      if (value.size > 0 && value.name) {
        fd.append(parentKey, value);
      }
    } else {
      // Append primitive values
      fd.append(parentKey, value);
    }
  }
}

/**
 * Converts a FormData instance back into a JavaScript object or array.
 *
 * @param {FormData} formData - The FormData instance to convert.
 * @returns {Object|Array|null} - The resulting object or array.
 */
export function fromFormdata(formData) {
  return handleTryCatch({
    n: "fromFormdata",
    c: !isFormData(formData, true),
    p: { formData },
    e: () => {
      if (!formData) return null;

      const object = {};

      for (const [key, value] of formData.entries()) {
        parseKey(object, key, value);
      }

      // If the object is purely an array (e.g., `{ "0": "A", "1": "B" }`), convert it to an actual array
      if (isPureArray(object)) {
        return Object.values(object);
      }

      return object;
    }
  });

  /**
   * Parses a FormData key into a nested object structure.
   *
   * @param {Object} obj - The object being populated.
   * @param {string} key - The FormData key.
   * @param {*} value - The value to assign.
   */
  function parseKey(obj, key, value) {
    const parts = key.replace(/\]/g, "").split("[");

    let current = obj;

    parts.forEach((part, index) => {
      if (index === parts.length - 1) {
        // Final key, assign value
        if (current[part] !== undefined) {
          current[part] = [].concat(current[part], value);
        } else {
          current[part] = value;
        }
      } else {
        // Create nested object/array if needed
        if (!current[part]) {
          current[part] = isNaN(parts[index + 1]) ? {} : [];
        }
        current = current[part];
      }
    });
  }

  /**
   * Checks if an object is purely an array (i.e., its keys are sequential numbers).
   *
   * @param {Object} obj - The object to check.
   * @returns {boolean} - True if the object is purely an array, false otherwise.
   */
  function isPureArray(obj) {
    const keys = Object.keys(obj);
    return keys.every((key, i) => String(i) === key); // Ensures keys are sequential numbers
  }
}

/**
 * Merges multiple objects, arrays, or FormData instances into a single FormData object.
 * 
 * @param {...(Object|Array|FormData)} sources - The sources to merge. Can be objects, arrays, or FormData.
 * @returns {FormData} - A new FormData instance containing all merged data.
 */
export function mergeFormData(...sources) {
  return handleTryCatch({
    n: "mergeFormData",
    c: !sources?.length,
    p: { sources },
    e: () => {
      const formData = new FormData();
      for (const data of sources) {
        appendData(formData, data);
      }
      return formData;
    }
  });

  /**
   * Recursively appends data to a FormData instance.
   * Handles objects, arrays, FormData, and primitive values correctly.
   *
   * @param {FormData} fd - The FormData object to append data to.
   * @param {*} data - The data to append (object, array, FormData, string, number, file, etc.).
   * @param {string} [parentKey=""] - The parent key for nested structures.
   */
  function appendData(fd, data, parentKey = "") {
    if (data == null) return; // Ignore null/undefined values

    if (data instanceof FormData) {
      // Handle merging FormData, ensuring keys don't conflict
      for (const [key, value] of data.entries()) {
        fd.append(parentKey ? `${parentKey}[${key}]` : key, value);
      }
    } else if (typeof data === "object" && !(data instanceof File) && !(data instanceof Blob)) {
      // Handle objects & arrays
      for (const key in data) {
        if (Object.prototype.hasOwnProperty.call(data, key)) {
          const value = data[key];
          const newKey = parentKey ? `${parentKey}[${key}]` : key;
          appendData(fd, value, newKey);
        }
      }
    } else {
      // Append primitive values or files
      fd.append(parentKey, data);
    }
  }
}