tournonsLaPage/plugins/admin-addon-media-metadata/admin-addon-media-metadata.js

/**
 * some of the code is based on the Admin Addon Media Rename by Dávid Szabó
 *     see https://github.com/david-szabo97/grav-plugin-admin-addon-media-rename
 */
$(function() {

	adminAddonMediaMetadata.metadata = {};

	var clickedElement;
	var fileName;
	var $elementName;
	var modal;
	var $modal;
	var isPageMedia = false;

	// Append modal
	$('body').append(adminAddonMediaMetadata.MODAL);

	$(document).off('click', '[data-dz-name], .dz-metadata-edit');
	$(document).on('click', '[data-dz-name], .dz-metadata-edit', function(e) {
		clickedElement = $(this);
		modal = $.remodal.lookup[$('[data-remodal-id=modal-admin-addon-media-metadata]').data('remodal')];
		$modal = modal.$modal;
		modal.open();

		// Populate fields
		elementName = clickedElement.closest('.dz-preview').find('[data-dz-name]')
		fileName = elementName.text();
		$('[name=filename]', $modal).val(fileName);
		if (mediaListOnLoad[fileName] !== undefined) {
			for (var i = 0; i < metadataFormFields.length; i++) {
				$('[name=' + metadataFormFields[i] + ']', $modal).val(mediaListOnLoad[fileName][metadataFormFields[i]]);
			}
		} else {
			for (var i = 0; i < metadataFormFields.length; i++) {
				$('[name=' + metadataFormFields[i] + ']', $modal).val('');
			}
		}
		$modal.find('form span.filename').text(fileName);

		// Reset loading state
		$('.loading', $modal).addClass('hidden');
//		$('.button', $modal).removeClass('hidden').css('visibility', 'hidden');
		$('.button', $modal).removeClass('hidden');

		isPageMedia = !clickedElement.closest('.dz-preview').hasClass('dz-no-editor');
		$modal.find('.block-toggle').toggleClass('hidden', !isPageMedia);
		$modal.find('.page-media-info').toggleClass('hidden', !isPageMedia);
		$modal.find('.non-page-media-info').toggleClass('hidden', isPageMedia);
	});

	/**
	 * add the new data dynamically to mediaListOnLoad JSON object
	 * for newly uploaded media files as well as for “older” files, overwriting the data already in that JSON object
	 * and save it in the YAML file
	 * Variables from above ($(document).on), like fileName and $modal are still available
	 */
	$(document).on('click', '[data-remodal-id=modal-admin-addon-media-metadata] .button', function(e) {
		// hiding the button and showing the loading icon
		$('.loading', $modal).removeClass('hidden');
		$('.button', $modal).addClass('hidden');

		// create the file object for newly uploaded files
		if (mediaListOnLoad[fileName] === undefined) {
			mediaListOnLoad[fileName] = new Object();
			mediaListOnLoad[fileName]['filename'] = fileName;
		}

		// Do request with JS Fetch API: https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch
		var data = new FormData();
		data.append('filename', fileName);
		data.append('admin-nonce', GravAdmin.config.admin_nonce);

		// add the new values to mediaListOnLoad (for later updates before page reload)
		// append the new values to the FormData (data.append)
		for (var i = 0; i < metadataFormFields.length; i++) {
			var newVal = $('[name=' + metadataFormFields[i] + ']', $modal).val();
			mediaListOnLoad[fileName][metadataFormFields[i]] = newVal;
			data.append(metadataFormFields[i], newVal);
		}

		fetch(adminAddonMediaMetadata.PATH, { method: 'POST', body: data, credentials: 'same-origin' })
			//.then(res => res.json())
			.then(result => {
				if (result.error) {
					var alertModal = $.remodal.lookup[$('[data-remodal-id=modal-admin-addon-media-metadata-alert]').data('remodal')];
					alertModal.open();
					$('p', alertModal.$modal).html(result.error.msg);
					return;
				}

				modal.close();
			});
	});

	// adding the “edit metadata” button next to all media files
	setInterval(function addMetadataButton() {
		$('.dz-preview').each(function(i, dz) {
			if ($(this).find('.dz-metadata-edit').length == 0) {
				var editButton = document.createElement('a');
				//editButton.href = 'javascript:undefined;';
				editButton.title = adminAddonMediaMetadataButton;
				editButton.className = 'dz-metadata-edit';
				editButton.innerText = adminAddonMediaMetadataButton;
				var fileName = $(this).find('[data-dz-name]').text();
				editButton.setAttribute('data-filename', fileName);
				$(this).append(editButton);
			}
			$(this).find('.dz-metadata').remove();
		});
	}, 1000);
});