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When completed, this script will do various things to portals. Initially, it will insert article titles from a category into the template in the selected article section (if there is one).
This section explains the source code, in detail. It is for JavaScript programmers, and for those who want to learn how to program in JavaScript. Hopefully, this will enable you to adapt existing source code into new user scripts with greater ease, and perhaps even compose user scripts from scratch.
You can only use so many comments in the source code before you start to choke or bury the programming itself. So, I've put short summaries in the source code, and have provided in-depth explanations here.
My intention is Threefold:
In addition to plain vanilla JavaScript code, this script relies heavily on the jQuery library.
If you have any comments or questions, feel free to post them at the bottom of this page under Discussions. Be sure to {{ping}} me when you do.
(general approach goes here)
More specifically, starting at the beginning...
An alias is one string defined to mean another. Another term for "alias" is "shortcut". In the script, the following aliases are used:
$
is the alias for jQuery (the jQuery library)
mw
is the alias for mediawiki (the mediawiki library)
These two aliases are set up like this:
( function ( mw, $ ) {}( mediaWiki, jQuery ) );
That also happens to be a "bodyguard function", which is explained in the section below...
The bodyguard function assigns an alias for a name within the function, and reserves that alias for that purpose only. For example, if you want "t" to be interpreted only as "transhumanist".
Since the script uses jQuery, we want to defend jQuery's alias, the "$". The bodyguard function makes it so that "$" means only "jQuery" inside the function, even if it means something else outside the function. That is, it prevents other javascript libraries from overwriting the $() shortcut for jQuery within the function. It does this via scoping.
The bodyguard function is used like a wrapper, with the alias-containing source code inside it, typically, wrapping the whole rest of the script. Here's what a jQuery bodyguard function looks like:
1 ( function($) {
2 // you put the body of the script here
3 } ) ( jQuery );
See also: bodyguard function solution.
To extend that to lock in "mw" to mean "mediawiki", use the following (this is what the script uses):
1 ( function(mw, $) {
2 // you put the body of the script here
3 } ) (mediawiki, jQuery);
For the best explanation of the bodyguard function I've found so far, see: Solving "$(document).ready is not a function" and other problems (Long live Spartacus!)
The ready() event listener/handler makes the rest of the script wait until the page (and its DOM) is loaded and ready to be worked on. If the script tries to do its thing before the page is loaded, there won't be anything there for the script to work on (such as with scripts that will have nowhere to place the menu item mw.util.addPortletLink), and the script will fail.
In jQuery, it looks like this: $( document ).ready(function() {});
You can do that in jQuery shorthand, like this:
$().ready( function() {} );
Or even like this:
$(function() {});
The part of the script that is being made to wait goes inside the curly brackets. But you would generally start that on the next line, and put the ending curly bracket, closing parenthesis, and semicolon following that on a line of their own), like this:
1 $(function() {
2 // Body of function (or even the rest of the script) goes here, such as a click handler.
3 });
This is all explained further at the jQuery page for .ready()
For the plain vanilla version see: http://docs.jquery.com/Tutorials:Introducing_$(document).ready()
Initially each script I write is made to work only on the vector skin, the skin under which I developed it, and by default the only skin for which it is initially tested with. To limit the script to working for vector only, I use the following if control structure:
if ( mw.config.get( 'skin' ) === 'vector' ) {
}
To test it with another skin, remove or comment out the above code from the script.
Many scripts are written to work on a particular page or page type, and might have unexpected results if run on some other page. So a deactivation filter is used so the program does not run for the wrong pages.
For example:
if (document.title.indexOf("Watchlist - Wikipedia") == -1) {
// use a return statement to end the local function and hence the program's body
// important: this approach does not work outside of a function
return;
}
What this if statement does is checks that the current page is not the one we want, and if that is true, we end the program via a return statement.
What return;
does when alone like this (without any parameters), is to end the highest-level function which it is within. And since the body of the program is also within that function, if the if statement isn't true, the program ends.
You could do something similar with a straight if construct without "return;", checking for a page match, but then you'd have to have your whole script body inside the construct, which adds a level of indentation. The more filters, the more levels of indentation. The above approach avoids unnecessary indentation, and makes it easier to keep track of the curly brackets, as the closing bracket isn't way off at the end of the program.
This is the reserved word var, which is used to declare variables. A variable is a container you can put a value in. To declare the variable portletlink, write this:
var portletlink
A declared variable has no value, until you assign it one, such as like this:
portletlink = "yo mama";
You can combine declaration and assignment in the same statement, like this:
var portletlink = mw.util.addPortletLink('p-tb', '#', 'Remove red links');
Caveat: if you assign a value to a variable that does not exist, the variable will be created automatically. If it is created outside of a function, it will have global scope. For user scripts used on Wikipedia, having a variable of global scope means the variable may affect other scripts that are running, as the scripts are technically part of the same program, being called via import from a .js page (.js pages are programs). So, be careful. Here are some scope-related resources:
Due to the way they are built, categories would be a near ideal place from where to automatically collect page names for Selected article sections.
Unfortunately, Lua can't access the members of a category.
Therefore, we need to find another way to do this.
The api command to list the pages in a category is list=categorymembers
. See https://en.wikipedia.org/w/api.php?action=help&recursivesubmodules=1&modules=main#query+categorymembers .
There is a user script that does something very similar to what we are after. User:Ais523/catwatch adds new category members to one's watchlist. It seems very likely that Catwatch could be adapted to do this for Selected article sections.
One thing it does is store category names in a js page, formatted in JavaScript as part of the program. I'd like to store the category names in the Selected article sections themselves, and not formatted as JavaScript.
And, of course, rather than add new category members to one's watchlist, we want to add them to the Selected article section as parameters to the transclusion template there.
It turns out that Catwatch.js accesses the categorylinks table for the data it needs (see discussion below). The author said that it was obsolete, as "MediaWiki has its own category-watchlisting functionality", and you could "use the watchlist table instead".
Seamless Wikipedia browsing. On steroids.
Every time you click a link to Wikipedia, Wiktionary or Wikiquote in your browser's search results, it will show the modern Wikiwand interface.
Wikiwand extension is a five stars, simple, with minimum permission required to keep your browsing private, safe and transparent.