Add more metadata to Asset Publisher

Currently the Asset Publisher allows to show some metadata about the assets but some good are missing. My suggestion: add the asset description and the last author of an asset. To do so, follow these steps:

1. Add these imports to this file https://github.com/liferay/liferay-portal/blob/master/portal-web/docroot/html/portlet/asset_publisher/init.jsp

   <%@ page import="com.liferay.portlet.documentlibrary.model.DLFileVersion" %>
   <%@ page import="com.liferay.portlet.documentlibrary.service.DLFileVersionLocalServiceUtil" %>
   

2. Change this line https://github.com/liferay/liferay-portal/blob/master/portal-web/docroot/html/portlet/asset_publisher/init.jsp#L215

   String allMetadataFields = "create-date,modified-date,publish-date,expiration-date,priority,author,view-count,categories,tags,description,last-author";
   

3. Change this line https://github.com/liferay/liferay-portal/blob/master/portal-web/docroot/html/portlet/asset_publisher/css/main.css#L145

   	.metadata-author, .metadata-last-author {
   

4. Add this style here https://github.com/liferay/liferay-portal/blob/master/portal-web/docroot/html/portlet/asset_publisher/css/main.css#L173

   	.metadata-description {
   		margin-right: 10px;
   	}
   

5. Add these lines here https://github.com/liferay/liferay-portal/blob/master/portal-web/docroot/html/portlet/asset_publisher/display/table.jsp#L177

   		else if (metadataFields[m].equals("description")) {
   			value = HtmlUtil.escape(assetEntry.getDescription());
   		}
   		else if (metadataFields[m].equals("last-author")) {
   			if (assetEntry.getClassName().equals("com.liferay.portlet.documentlibrary.model.DLFileEntry")) {
   				DLFileVersion fileVersion = DLFileVersionLocalServiceUtil.getLatestFileVersion(assetEntry.getClassPK(), true);
   				
   				value = HtmlUtil.escape(fileVersion.getStatusByUserName());
   			} else {
   				String userName = PortalUtil.getUserName(assetRenderer.getUserId(), assetRenderer.getUserName());
   
   				value = HtmlUtil.escape(userName);
   			}
   		}
   

6. Add these lines here https://github.com/liferay/liferay-portal/blob/master/portal-web/docroot/html/portlet/asset_publisher/asset_metadata.jspf#L64

   	else if (metadataFields[j].equals("description")) {
   		value = HtmlUtil.escape(assetEntry.getDescription());
   	}
   	else if (metadataFields[j].equals("last-author")) {
   		if (assetEntry.getClassName().equals("com.liferay.portlet.documentlibrary.model.DLFileEntry")) {
   			DLFileVersion fileVersion = DLFileVersionLocalServiceUtil.getLatestFileVersion(assetEntry.getClassPK(), true);
   			
   			value = LanguageUtil.get(pageContext, "by") + StringPool.SPACE + HtmlUtil.escape(fileVersion.getStatusByUserName());
   		} else {
   			String userName = PortalUtil.getUserName(assetRenderer.getUserId(), assetRenderer.getUserName());
   
   			value = LanguageUtil.get(pageContext, "by") + StringPool.SPACE + HtmlUtil.escape(userName);
   		}
   	}
   

Furthermore there's a problem with author<>last author. The author for dlfiles is always the creator while on journals/web content the author is the last editor. To fix this, change these lines: https://github.com/liferay/liferay-portal/blob/master/portal-web/docroot/html/portlet/asset_publisher/display/table.jsp#L144 and https://github.com/liferay/liferay-portal/blob/master/portal-web/docroot/html/portlet/asset_publisher/asset_metadata.jspf#L49

		String userName = assetEntry.getUserName();

You will also need to add "last-author" to the language files.