Ok, bear with me a bit.
Encouragement in these forums has made me consider turning my periodic table demo from a “look what we can do in TiddlyWiki” showcase into something that might actually be useful to various people. My first thought would be Chemistry students. I can easily see some training games based on the data and the table. I can imagine flash cards. I can see allowing students to add notes to the information, from the trivial (“IronMan’s suit isn’t actually made of Iron”) to the much more serious results of their own experiments. I can see them adding custom fields for their own uses, personalizing the wiki, adding new reports. I can see all sorts of possibilities.
To do this, it would make sense to have students work in their own copy of the data, with the “official” parts hidden beneath. The most likely alternative would be to clone the official data tiddler into their own playground, simply by overriding the shadowed tiddler But this has a real problem. Here’s a story:
Do you remember Beth? She was the short, cute, and very friendly girl who sat in front of you in Sophomore Chemistry class. Remember joking with her about how baseball coaches probably don’t make the best teachers? She went on to be valedictorian. No? Well, anyway, somehow, back in 1981 (am I dating myself here?) Beth has a copy of this periodic table wiki for her studies. She has been doing experiments with Tin, and has added copious notes to her copy of the Tin tiddler. She notices an anomaly. She did an experiment and found Tin’s melting point of 229.4°. (Pretty good for a High School student. The official number is 232.06°, but then Beth was always meticulous.)
But Beth looks in the wiki, and sees 505.21°. What? Huh? She couldn’t be that far off. She goes to the library to look it up. (Hey, this is my story; I can imagine she has TiddlyWiki but no Google!) Sure enough, she’s right, or close enough. So she changes the melting point field; it’s great that she could do this, so flexible. And because she’s conscientious, she also sends off a letter (yes, ink on paper; it’s 1981) to the guy who created this system. And she continues on adding her content, and you and she continue to read the textbook and help instruct the rest of the class because Mr. H certainly isn’t going to do it.
It turns out that there are several other fields the wiki got wrong, and she adds additional corrections. She loses track a little bit of what values are hers and what are from the original data, and she may have overwritten a few unnecessarily, and it’s possible she got something wrong. She can’t ask the moron at the front of the classroom; he’ll ramble an answer until he manages to get the familiar ground of sports. And she can’t ask you; you’re studying Lead. And Lynne has Potassium. But she’s not overly worried about this; her notes are good.
A week later she gets a letter back from the wiki’s creator. He’s touched by her writing to him, but has to correct her. All the temperatures in the wiki are in degrees Kelvin, not degrees Celsius. And sure enough, with absolute zero of -273.15° Celsius, the official melting point of Tin is 505.21° Kelvin. It looks like some of her other “corrections” were also mistaken.
How does she fix this?
Here’s how I know to do it currently in Tiddlywiki: she deletes her tiddler full of her own notes, restoring the shadowed plugin version. Beth is smart, so she’ll make a copy first, and painstakingly copy back over the notes she had about Tin into a fresh copy. Perhaps there’s another way. I don’t know how to see the plugin tiddler when it’s being shadowed by your own, but I wouldn’t be shocked to find out that it’s possible. Then she could copy back the changed fields from there. Either way, this is taking time away from the important parts of first-period Chemistry: playing with the Bunsen burners, laughing at the teacher’s gaffes, and gossiping with her friends. (You, an awkward, nerdy teenage boy feel uplifted to be part of this circle of friends, but that’s another story.) Anyway, it’s an annoying process and makes the tool feel a bit less friendly.
If there was a way for tiddlers to have prototypes, here’s how she’d do it. Her own version is a tiddler whose parent is the shadow Tin tiddler. She just deletes the field meltingpoint
from her own tiddler. And boilingpoint
. And density
and specificheat
. The underlying values shine through from beneath and everything is restored. All is well with the world.
As I said, it’s quite possibly a ridiculously stupid idea. But forget my mentioning JavaScript. That was just an analogy for those familiar with the language. A much more approachable way to ask this (and I’ll edit the OP to include it) is this:
We have a shadowing mechanism, allowing us to use our tiddler in place of another, even though that other one still exists and will be resurrected the minute our own is deleted. Could we do the same thing at the field level?