sysadmin reconstruct groups page (#4036)

* sysadmin reconstruct groups page

* [system admin] groups: fixup & improvement

* [system admin] groups: fixup & improvement

frontend/src/components/dialog/sysadmin-dialog/sysadmin-group-add-member-dialog.js

@@ -0,0 +1,60 @@
+import React from 'react';
+import PropTypes from 'prop-types';
+import { Button, Modal, ModalHeader, ModalBody, ModalFooter } from 'reactstrap';
+import { gettext } from '../../../utils/constants';
+import UserSelect from '../../user-select';
+
+const propTypes = {
+  toggle: PropTypes.func.isRequired,
+  addMembers: PropTypes.func.isRequired
+};
+
+class SysAdminGroupAddMemberDialog extends React.Component {
+
+  constructor(props) {
+    super(props);
+    this.state = {
+      selectedOptions: null,
+      isSubmitBtnDisabled: true
+    };
+  }
+
+  handleSelectChange = (options) => {
+    this.setState({
+      selectedOptions: options,
+      isSubmitBtnDisabled: !options.length
+    });
+  }
+
+  addMembers = () => {
+    let emails = this.state.selectedOptions.map(item => item.email);
+    this.props.addMembers(emails);
+    this.props.toggle();
+  } 
+
+  render() {
+    const { isSubmitBtnDisabled } = this.state;
+    return (
+      <Modal isOpen={true}>
+        <ModalHeader toggle={this.props.toggle}>{gettext('Add Member')}</ModalHeader>
+        <ModalBody>
+          <UserSelect
+            ref="userSelect"
+            isMulti={true}
+            className="reviewer-select"
+            placeholder={gettext('Search users')}
+            onSelectChange={this.handleSelectChange}
+          /> 
+        </ModalBody>
+        <ModalFooter>
+          <Button color="secondary" onClick={this.props.toggle}>{gettext('Cancel')}</Button>
+          <Button color="primary" onClick={this.addMembers} disabled={isSubmitBtnDisabled}>{gettext('Submit')}</Button>
+        </ModalFooter>
+      </Modal>
+    );
+  }
+}
+
+SysAdminGroupAddMemberDialog.propTypes = propTypes;
+
+export default SysAdminGroupAddMemberDialog;