UserScript Writing 101
Intro for the Slow
If you're not a moron, skip this section.
As you can see, people in the comments are pretty angry about this guide, because they couldn't figure out what I was getting at. (Briefly read those comments, and my response). As I've responded, this is NOT a one-page resource. This is a succinct, easy to follow article on HOW and WHERE to learn about writing userscripts, especially if you (like me) hated "Dive Into Greasemonkey" as a supposedly "one-page" resource. I am not going to re-write what has already been written. I WILL tell you where to find what has been written. Go die in a fire if you have a problem with that.
"GUIDE" != "TUTORIAL". Jeez.
A Short Piece about me/this
I've been a Greasemonkey for about a year now: meaning that this is quite easy to learn. I wrote this because learning Greasemonkey entails things other than the bullshit located at Dive Into Greasemonkey. Honestly, that site isn't helpful at all. Miserable, really. Read on.
Introduction
So you want to learn Greasemonkey? Excellent! This short guide (should) help you to be well on your way to being a scriptwriter. Just because I've sectioned off parts doesn't mean you should skip; read everything (it isn't that much)!
Background
What is Greasemonkey? Greasemonkey is an add-on for Mozilla Firefox. In short, it uses JavaScript to enhance or change the way you interact with the web. This, of course, means A LOT of things are possible.
What Can't Greasemonkey Do?
Greasemonkey is used for many incredibly complex things. At userscripts.org, we've seen scripts that have solved captcha's, interact with and hack Adobe Flash objects, as well as implement basic high score list exploitation.
But people often mistake Greasemonkey as THE answer to all your dirty hacking fantasies. It is not. For example, frequent requests are made for viewing private MySpace and Facebook profiles. Though this is possible, Greasemonkey doesn't make it ANY easier.
Technical Background
Greasemonkey uses interpreted JavaScript, not to be confused with Sun Microsystem's inferior compiled bytecode language, Java. Therefore, you will not need the JDK or Java Runtime Files for ANY reason whatsoever.
JavaScript is used mainly for maintaining HTML structures by a convention known as Document Object Model (DOM). Wikipedia has a wonderful SVG graphic representing the hierarchy of objects in the DOM.
A bit about standards: all these browsers, all these plugins, and all these different ways to interact with the web. How does it all come together? Web standards (HTTP, HTML, CSS, XML, XPath, SVG, etc.) are maintained by the W3C (World Wide Web Consortium). Although you (or browser developers) aren't required to implement them per se, their conventions are extremely well organized, well thought and agreed upon by many, so if you need to understand it all better, check out their recommendations and drafts for new web technologies.
About JavaScript
JavaScript is probably the sexiest language ever. It is inherently free-form and therefore, awesome. You'll find that it's a lot of fun, and, if you use it long enough, useful outside the realm of web development and Greasemonkey scripting.
As I mentioned in the "Technical Background" section, JavaScript is used for maintaining HTML pages. This will clue you in on the next section, "The Order of Things to Learn". Greasemonkey is sort of like JavaScript on steroids though. It has more "powers". You'll learn about these extra powers as well.
The Order of Things to Learn
Look to the "Resources" section for places to learn about these.- HTML. Hypertext Markup Language. Not the same "language" as JavaScript. This is a markup language, meaning it's a bunch of text that is meant to represent some type of structure, in this case, a web page.
- XML. Extensible Markup Language. In case you didn't realize, HTML itself is a type of "XML". Learning XML is important because many popular websites (YouTube, Facebook, Last.fm) use XML to interact with data. Since you already know HTML by this point, understanding XML should be cake.
- CSS. Cascading Style Sheets. This is the way HTML (should be) stylized. You'll want to learn this.
- JavaScript. Learn all the basics: data types, functions, JavaScript's native functions like prompt, alert, etc.
- The Greasemonkey Extras. Like I said, Greasmonkey == JavaScript, with a lot of extras. A specific page listing the API's can be found here.
Final
That's it. If you have any questions or suggestions concerning the guide, leave a comment here, or send me an email (aavindraa@gmail.com).
Resources
Google. This is your number one resource. In case you haven't noticed yet, you can google most of your questions and come across the answer quickly. Learn it, live it, love it.W3Schools, home of many easy to understand, incredibly useful tutorials.
Mozilla Developer Center (MDC). Here, you can find a lot of API information about Firefox, as well as it's implementation of JavaScript and it's features.
Greasespot, a wiki for learning all about what Greasemonkey has to offer.
W3C. The central source for web standards.
Of course, this site. Search the forums, look at other scripts on here for inspiration.
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heh, javascript is freeform and that's what I love about it too
I don't think Dive Into Greasemonkey's that bad, I mean, when I started learning javascript I did read it :p
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Just, instead of "Dive Into Greasemonkey" is more correct to look online book
http://commons.oreilly.com/wiki/index.php/Greas...
It seems examples of "Dive Into Greasemonkey" author takes from this book =)
But some even don't work or written for old Greasemonkey.
Although intricate confusing signs on the stage of newcomer might be useful :D
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Couple things. When you say UserScript Writing 101, and then provide no help in writing scripts and then criticize another site for doing it, it's sad. You don't mention about creating the script or adding them to greasemonkey so I can only hope that you are just adding onto the information located on that site in which case I am fine with it. Second, you call Java an inferior language based on it being a completely different type of code which shows your lack of knowledge of programming and that sort of insults me, however, it may simply be that you are not aware of Java and how it works. For those unaware, JavaScript was made to look like Java, which is why you can get them confused, but they serve totally different purposes.
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Neither talk about Java ...
I call Java? Or we call Java?
I hope for pharmacy near you.
And examination for your approvings not here.
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I don't think this guide needs to go, but it does need a new title. For someone looking to write their first userscript (as suggested by the current title "UserScript Writing 101") this guide is not appropriate.
This guide could perhaps be better titled,
"Avindra's Mildly Invective Rant In Which No Actual Details Are Introduced, Except Perhaps Some Dark Hints About the Inferiority of Other Documentation and Other Languages, and Then A Few Short Links To Some Real Documentation (Including the Aforementioned Inferior Guides, Which Avindra Confesses to Having Learned At the Feet Of Before Gracing Us With Avindra's Opinion In This Document). BTW, Stuff Avindra Likes Is Cool.".
If that was the title, the content would be perfect.
Thanks for sharing, Avindra.
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I am not providing useful examples because as you can see, I've linked to resources which I think are more useful than Dive Into Greasemonkey.
I wasn't intending at all for this to be a place TO learn, but a place to find WHERE to learn. If you have trouble using my guide because you want everything you need on a single page, go die in a fire.
@Krucifide:
I hate Java not because it's "different" but because it's slow and imo, pretentious about it's "strong" typing. I know no devs who actually celebrate Java and just adore it. And for YOUR information, JavaScript was NOT made to look like Java, it was made to look like "C", and the name JavaScript was used to make it popular because Java was popular at the time. This information can be found with a quick google search, which I see you have failed to do.
Also, I know Java is for a completely different purpose. I clearly make that point in my guide. In fact, it's the only reason I brought it up in the first place. Why are you telling me something I agree with again? Are you re-telling people reading your comment perhaps?
@swiftcase:
"Greasemonkey Hacks" is FAR too in depth and is probably for the most daft person imaginable who's barely used a computer.
Also, if you're going to call me crazy, learn how to speak English somewhat fluidly first?
@Chris:
Yeah, you pretty much nailed it. Perhaps the title is a bit misleading. Do people really base what they expect off the title of anything though? I don't.