Modification of https://github.com/micjamking/succinct to allow the plugin to show the longer versions of text on click, not quite as customizable in practice.

gistfile1.txt

/*
 * Copyright (c) 2013 Mike King (@micjamking)
 *
 * jQuery Succinct plugin
 * Version 1.0.1 (July 2013)
 *
 * Licensed under the MIT License
 */

 /*global jQuery*/
(function($){
	'use strict';

	$.fn.succinct = function(options){

		var defaults = {
				size: 240,
				omission: '...',
				ignore: true
			},
			options = $.extend(defaults, options);

		return this.each(function(i, el){

			var textDefault,
				textTruncated,
				elements = $(this),
				regex    = /[!-\/:-@\[-`{-~]$/;

			var untruncate = function(e) {
				var link = $(e.target);
				var parent = link.parent();

        // replace truncated text with untruncated text
				parent.html(parent.data('default'));

        // create the show less link
				link = document.createElement('a');
				link.className = 'show_less';
				link.href = "#";
				link.rel = i;
				link.innerHTML = " — show less";

        // add it to the end of the long text, and attach truncate event
				parent.append(link);
				link.onclick = truncate;

				return false;
			}

			var truncate = function(){

				elements.each(function(){
			    // remove any previous links, so they aren't truncated again
					$(this).find('.show_less, .show_more').remove();
					
					// retrieve the current text and copy it for retrieval in untruncate
					textDefault = $(this).html();
					$(this).data('default', textDefault);

					if (textDefault.length > options.size) {
						textTruncated = $.trim(textDefault).
										substring(0, options.size).
										split(' ').
										slice(0, -1).
										join(' ');

						if (options.ignore) {
							textTruncated = textTruncated.replace( regex , '' );
						}
            
            // create the link to show more of the text
						var link = document.createElement('a');
						link.className = 'show_more';
						link.href = "#";
						link.rel = i;
						link.innerHTML = "read more";
						
						// replace element with truncated text
						$(this).html(textTruncated + '... ');
						
						// add link and attach untruncate event
						$(this).append(link);
						link.onclick = untruncate;
					}
				});

				return false;
			};

			var init = function() {
				truncate();
			};

			init();
		});
	};
})(jQuery);

Thx Nic !

Hi brzrkr, thanks for the modification! It helps a lot!

I noticed one thing:
When there are multiple truncates on the page, when you click on the second or more "read more", only the last truncate will have "read more" button, and the former "read more"s will disappear..
This is because the default data of the every truncated item is reseted to be $(this).html(); every time when a truncate happens( line 58,59), and the already truncated item only have limited text in html, so it will not trigger the truncate.

Solved the problem with replacing line 59 with textDefault = $(this).data('default') || $(this).html();