Jump to content

User:Evad37/TextDiff.js

From Wikipedia, the free encyclopedia
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.
Note: After saving, you have to bypass your browser's cache to see the changes. Google Chrome, Firefox, Microsoft Edge and Safari: Hold down the ⇧ Shift key and click the Reload toolbar button. For details and instructions about other browsers, see Wikipedia:Bypass your cache.
/***************************************************************************************************
 TextDiff --- by Evad37
 > Shows a simpler, text-only diff
 > Alpha version
***************************************************************************************************/
// <nowiki>
$( function($) {
	
/* ========== Load dependencies ================================================================= */
// Load resoucre loader modules
mw.loader.using( ['mediawiki.util', 'mediawiki.api', 'ext.gadget.libExtraUtil'], function () {

// Do not operate if not viewing a diff, or if there is no difference
if ( !mw.util.getParamValue('diff') || $('.mw-diff-empty').length ) {
	return;
}

var config = {
	'script': {
		'version': '0.3.0-alpha'
	},
	'params': {
		'diff': mw.util.getParamValue('diff'),
		'oldid': mw.util.getParamValue('oldid')
	},
	'mw': mw.config.get(['wgPageName', 'wgCurRevisionId'])
};

var api = new mw.Api( {
    ajax: {
        headers: { 
			'Api-User-Agent': 'TextDiff/' + config.script.version + 
				' ( https://en.wikipedia.org/wiki/User:Evad37/TextDiff )'
		}
    }
} );

/* ========= Processing functions =============================================================== */

/**
 * normaliseIds
 *
 * Get normalised revision ids (lookup the current / previous / next id if present)
 * @param
 */
var normaliseIds = function(diffParam, oldidParam, title) {
	var relativeDiffWords = ['cur', 'prev', 'next'];
	
	if ( !diffParam ) {
		return $.Deferred().reject('No diff specified');
	}
	if ( !$.isNumeric(diffParam) && relativeDiffWords.indexOf(diffParam) === -1 ) {
		return $.Deferred().reject("Bad diff specified: Must be numeric or one of 'cur', 'prev', 'next'");
	}

	// Both params have numeric ids
	if ( $.isNumeric(diffParam) && $.isNumeric(oldidParam) ) {
		return $.Deferred().resolve({
			'from': oldidParam,
			'to': diffParam
		});
	}
	
	// Neither param has a numeric ids 
	if ( !$.isNumeric(diffParam) && !$.isNumeric(oldidParam) ) {
		return lookupIdsFromRelation(
			'prev',
			config.mw.wgCurRevisionId,
			title
		);
	}
	
	// Only diff param has a numeric id
	if ( $.isNumeric(diffParam) ) {
		return lookupIdsFromRelation(oldidParam, diffParam, title);
	}
	
	// Only oldid param has a numeric id
	return lookupIdsFromRelation(diffParam, oldidParam, title);
};

/**
 * lookupIdsFromRelation
 *
 * @param
 */
var lookupIdsFromRelation = function(relation, otherId, title) {
	return api.get({
		action: 'compare',
		format: 'json',
		fromrev: otherId, //|| false,
		fromtitle: ( $.isNumeric(otherId) ) ? '' : title,
		torelative: relation,
		prop: 'ids'
	})
	.then(function(result) {
		return {
			'from': result.compare.fromrevid,
			'to': result.compare.torevid || config.mw.wgCurRevisionId
		};
	});
};

/**
 * makeText
 *
 * Shorthand for #grabWikitext then #toPlaintext
 */
var makeText = function(id) { return grabWikitext(id).then(toPlaintext); };

/**
 * grabWikitext
 *
 * Gets the wikitext and page title of a specific revision of a page
 *
 * @param {string} page
 *   Page title
 * @param {int} revid
 *   Old revision id
 * @return {Deferred} Promise that is resolved with: {object} results, with keys
 *     wikitext: {string},
 *     pageTitle: {string}
 */
var grabWikitext = function(revid) {
	
	return api.get({
		"action": "query",
		"format": "json",
		"prop": "revisions",
		"revids": revid,
		"rvprop": "content"
	})
	.then(function(response) {
		var pageid = Object.keys(response.query.pages)[0];
		var wikitext = response.query.pages[pageid].revisions[0]['*'];
		var title = response.query.pages[pageid].title;
		return { 'wikitext':wikitext, 'pageTitle':title };
	});

};

/**
 * toPlaintext
 *
 * Transforms a wikitext string into a plaintext string. Images are replaced with alt text.
 *
 * @param {object} info
 *	 @param {string} info.wikitext
 *     Wikitext to be expanded
 *   @param {string} info.pageTitle
 *     Page title, to give context to variables like {{PAGENAME}} 
 * @return {Deferred} Promise that is resolved with: {string} transformed wikitext
 */
var toPlaintext = function(info) {
	return api.post({
		"action": "parse",
		"format": "json",
		"title": info.pageTitle,
		"text": info.wikitext,
		"prop": "text",
		"disablelimitreport": 1,
		"disableeditsection": 1,
		"contentmodel": "wikitext",
		"mobileformat": 1,
		"noimages": 1
	})
	.then( function(response) { return response.parse.text['*']; } )
	.then( function(parsetext) { return $(parsetext).text(); } );
};

/*
Strip lines where that line, the two previous lines, and the two next lines, are identical.
Parameters are arrays of text, with one line of text per array element
*/
var stripIdenticalLines = function(lines, otherLines) {
	return lines.map(function(line, index) {
		if (
			lines[index-2] === otherLines[index-2] &&
			lines[index-1] === otherLines[index-1] &&
			lines[index] === otherLines[index] &&
			lines[index+1] === otherLines[index+1] &&
			lines[index+2] === otherLines[index+2]
		) {
			return '';
		}
		return line;
	});
};

var stripIdenticalText = function(fromText, toText) {
	var fromLines = fromText.split('\n');
	var toLines = toText.split('\n');
	return $.Deferred().resolve(
		stripIdenticalLines(fromLines, toLines).join('\n'),
		stripIdenticalLines(toLines, fromLines).join('\n')
	);
};

/**
 * makeDiff
 *
 * @param
 */
var makeDiff = function(fromText, toText) {
	return api.post({
		"action": "compare",
		"format": "json",
		"fromtext": fromText,
		"fromcontentmodel": "text",
		"totext": toText,
		"tocontentmodel": "text",
		"prop": "diff"
	})
	.then( function(response) { return response.compare['*']; });
};

/**
 * showDiff
 *
 * @param
 */
var showDiff = function(diffRow) {
	$(diffRow).filter('tr').addClass('textdiff-row').hide().insertAfter('#textDiff-buttonRow').show('fast');
	$('tr.textdiff-row').last().nextAll().addClass('origdiff-row').hide('fast');
	$('#textDiff-button').prop('disabled', false).text('Toggle textual diff');
};

var onError = function(code, jqxhr) {
	$('#textDiff-button').text('Error loading textual diff').after(
		$('<div>').addClass('error').append( extraJs.makeErrorMsg(code, jqxhr) )
	);
};


/* ========= Set up =============================================================== */
var doTextDiff = function(diffParam, oldIdParam, pageName) {
	normaliseIds(diffParam, oldIdParam, pageName)
	.then(function(ids) {
		return $.when(makeText(ids.from), makeText(ids.to));
	})
	.then(stripIdenticalText)
	.then(makeDiff)
	.then(showDiff, onError);
};

var $buttonRow = $('<tr>').attr('id', 'textDiff-buttonRow').append(
	$('<td>').attr('id', 'textDiff-buttonCell').append(
		$('<div>').css('text-align', 'center').append(
			$('<button>')
			.attr('title', 'Show textual diff view')
			.text('Textual diff')
			.click(function() {
				$(this).hide().next().show();
				doTextDiff(config.params.diff, config.params.oldid, config.mw.wgPageName);
			}),
			
			$('<button>')
			.attr({'id':'textDiff-button', 'title':'Toggle textual diff view'})
			.text('Textual diff loading...')
			.prop('disabled', 'true')
			.hide()
			.click(function() {
				$('tr.textdiff-row, tr.origdiff-row').toggle();
			})
		)
	)
);

$('table.diff').find('tr').first().after($buttonRow);
$('#textDiff-buttonCell').attr('colspan', '4');

/* ========== Export code for testing by /test.js =============================================== */
window.testTextDiff = {
	'config': config,
	'api': api,
	'normaliseIds': normaliseIds,
	'lookupIdsFromRelation': lookupIdsFromRelation,
	'makeText': makeText,	
	'grabWikitext': grabWikitext,
	'toPlaintext': toPlaintext,
	'makeDiff': makeDiff,
	'showDiff': showDiff,
	'doTextDiff': doTextDiff
};

});
});
// </nowiki>