tt-rss/plugins/shorten_expanded/init.js

var _shorten_expanded_threshold = 1.5; //window heights

function expandSizeWrapper(id) {
	try {
		var row = $(id);

		console.log(row);

		if (row) {
			var content = row.select(".contentSizeWrapper")[0];
			var link = row.select(".expandPrompt")[0];

			if (content) content.removeClassName("contentSizeWrapper");
			if (link) Element.hide(link);

		}
	} catch (e) {
		exception_error("expandSizeWrapper", e);
	}

	return false;

}

require(['dojo/_base/kernel', 'dojo/ready'], function  (dojo, ready) {

	ready(function() {
		PluginHost.register(PluginHost.HOOK_ARTICLE_RENDERED_CDM, function(row) {
			if (getInitParam('cdm_expanded')) {

				window.setTimeout(function() {
					if (row) {
						if (row.offsetHeight >= _shorten_expanded_threshold * window.innerHeight) {
							var content = row.select(".cdmContentInner")[0];

							if (content) {
								content.innerHTML = "<div class='contentSizeWrapper'>" +
									content.innerHTML + "</div><button class='expandPrompt' onclick='return expandSizeWrapper(\""+row.id+"\")' "+
									"href='#'>" + __("Click to expand article") + "</button>";

							}
						}
					}
				}, 150);
			}

			return true;
		});
	});

});