feat: Ability to upload multiple attachments at once

Closes #908

client/src/components/CardModal/AttachmentAddStep.jsx

@@ -28,7 +28,7 @@ const AttachmentAddStep = React.memo(({ onCreate, onClose }) => {
       </Popup.Header>
       <Popup.Content>
         <Menu secondary vertical className={styles.menu}>
-          <FilePicker onSelect={handleFileSelect}>
+          <FilePicker multiple onSelect={handleFileSelect}>
             <Menu.Item className={styles.menuItem}>
               {t('common.fromComputer', {
                 context: 'title',

client/src/components/CardModal/AttachmentAddZone/AttachmentAddZone.jsx

@@ -5,6 +5,7 @@ import { useTranslation } from 'react-i18next';
 import { closePopup } from '../../../lib/popup';
 
 import { useModal } from '../../../hooks';
+import { isActiveTextElement } from '../../../utils/element-helpers';
 import TextFileAddModal from './TextFileAddModal';
 
 import styles from './AttachmentAddZone.module.scss';
@@ -24,13 +25,14 @@ const AttachmentAddZone = React.memo(({ children, onCreate }) => {
 
   const handleDropAccepted = useCallback(
     (files) => {
-      submit(files[0]);
+      files.forEach((file) => {
+        submit(file);
+      });
     },
     [submit],
   );
 
   const { getRootProps, getInputProps, isDragActive } = useDropzone({
-    multiple: false,
     noClick: true,
     noKeyboard: true,
     onDropAccepted: handleDropAccepted,
@@ -49,39 +51,44 @@ const AttachmentAddZone = React.memo(({ children, onCreate }) => {
         return;
       }
 
-      const file = event.clipboardData.files[0];
+      const { files, items } = event.clipboardData;
 
-      if (file) {
+      if (files.length > 0) {
+        [...files].forEach((file) => {
           submit(file);
+        });
+
         return;
       }
 
-      const item = event.clipboardData.items[0];
-
-      if (!item) {
+      if (items.length === 0) {
         return;
       }
 
-      if (item.kind === 'file') {
-        submit(item.getAsFile());
-        return;
-      }
-
-      if (
-        ['input', 'textarea'].includes(event.target.tagName.toLowerCase()) &&
-        event.target === document.activeElement
-      ) {
+      if (items[0].kind === 'string') {
+        if (isActiveTextElement(event.target)) {
           return;
         }
 
         closePopup();
         event.preventDefault();
 
-      item.getAsString((content) => {
+        items[0].getAsString((content) => {
           openModal({
             content,
           });
         });
+
+        return;
+      }
+
+      [...items].forEach((item) => {
+        if (item.kind !== 'file') {
+          return;
+        }
+
+        submit(item.getAsFile());
+      });
     };
 
     window.addEventListener('paste', handlePaste);

client/src/lib/custom-ui/components/FilePicker/FilePicker.jsx

@@ -3,7 +3,7 @@ import PropTypes from 'prop-types';
 
 import styles from './FilePicker.module.css';
 
-const FilePicker = React.memo(({ children, accept, onSelect }) => {
+const FilePicker = React.memo(({ children, accept, multiple, onSelect }) => {
   const field = useRef(null);
 
   const handleTriggerClick = useCallback(() => {
@@ -12,11 +12,11 @@ const FilePicker = React.memo(({ children, accept, onSelect }) => {
 
   const handleFieldChange = useCallback(
     ({ target }) => {
-      if (target.files[0]) {
-        onSelect(target.files[0]);
+      [...target.files].forEach((file) => {
+        onSelect(file);
+      });
 
       target.value = null; // eslint-disable-line no-param-reassign
-      }
     },
     [onSelect],
   );
@@ -32,6 +32,7 @@ const FilePicker = React.memo(({ children, accept, onSelect }) => {
         ref={field}
         type="file"
         accept={accept}
+        multiple={multiple}
         className={styles.field}
         onChange={handleFieldChange}
       />
@@ -42,11 +43,13 @@ const FilePicker = React.memo(({ children, accept, onSelect }) => {
 FilePicker.propTypes = {
   children: PropTypes.element.isRequired,
   accept: PropTypes.string,
+  multiple: PropTypes.bool,
   onSelect: PropTypes.func.isRequired,
 };
 
 FilePicker.defaultProps = {
   accept: undefined,
+  multiple: false,
 };
 
 export default FilePicker;

client/src/utils/element-helpers.js

@@ -1,5 +1,8 @@
-// eslint-disable-next-line import/prefer-default-export
 export const focusEnd = (element) => {
   element.focus();
   element.setSelectionRange(element.value.length + 1, element.value.length + 1);
 };
+
+export const isActiveTextElement = (element) =>
+  ['input', 'textarea'].includes(element.tagName.toLowerCase()) &&
+  element === document.activeElement;