How do you use the core filter macro?

[Alex Hough]

The external resources on tw.org [1] are not clear to me. However, I
am thinking that using this built in function would be better than
some plugin solutions. This would reduce 'plugin dependency' which i
am now convinced is not a good thing.

ALex

http://tiddlywiki.org/wiki/Filtering

[Eric Shulman]

at the bottom of that wiki page is a section called "External
links"... included there is a link to this thread from way back in
December, 2007:

http://groups.google.com/group/TiddlyWiki/browse_thread/thread/db7259852b1e706d/b8b83a918a770cdb?#b8b83a918a770cdb

in which I explained the filtering syntax that had just been added to
TW2.3.0.

Here's a repost:
--------------
This new syntax extends the familiar "space-separated list of
tiddlers" (as used in DefaultTiddlers and many other places).

"[tag[value]]" is automatically 'expanded' to a list of all tiddlers
that match the given tag value, while "[sort[+/-fieldname]]" sorts the
list of tiddlers by the specified field name, with a prefix of "+" or
"-" to indicate an ascending or descending sort order.

For example:
SomeTiddler [tag[sometag]] SomeOtherTiddler [sort[+title]]

is a list that includes SomeTiddler and SomeOtherTiddler, PLUS all
tiddlers tagged with "sometag"... all sorted alphabetically.

Another example... if you enter
ThisTiddler ThatTiddler MyTiddler YourTiddler [sort[-modified]]

as the content for [[DefaultTiddlers]], then your document will always
start with the same four specified tiddlers showing, but will display
the more recently changed tiddlers first.

--------------

Note: if you want to apply more complex tag matching criteria using
Boolean logic (and, or, not, and nested parentheses), e.g.:
[tag[foo OR (bar AND baz) AND NOT (mumble AND (frotz OR gronk))]]

then you still want to use this plugin:
http://www.TiddlyTools.com/#MatchTagsPlugin
http://www.TiddlyTools.com/#MatchTagsPluginInfo

enjoy,
-e

[alex]

Hi Eric,

I'd read your previous post and looked at it for a long time.
I made a test case.It seems that the filter only works in
DefaultTiddlers or a list.

Its not clear form TW.org or your post that the filter syntax has to
be used in a list or DefaultTiddlers. Reading your documentation for
matchTags[1] explains the built in function though. It would be good
if core functions were documented like this. It would save a lot of
time i think.

In the past I would have just gone and installed the TiddlyTools
plugin, but now i am gettig to the stage where i want to learn about
core fuctions and how to use them all. (I'm building a 'howto' for
myself.) Sometimes i only want to do something simple and a plugin is
too much.

Re:This new syntax extends the familiar "space-separated list of
tiddlers" (as used in DefaultTiddlers and many other places). What are
these places?

I've made a test TW to explore[1]. It seems to me that the "+" and "-"
are not working.

Also

Alex
[1] http://www.tiddlytools.com/#MatchTagsPlugin
[2] file:///Users/alexhough/Dropbox/Public/Tests.html

[Alex Hough]

In the last post [2] should have been

[2] https://files.getdropbox.com/u/1316865/Tests.html

[FND]

> Its not clear form TW.org or your post that the filter syntax has to
> be used in a list or DefaultTiddlers. Reading your documentation for
> matchTags[1] explains the built in function though. It would be good
> if core functions were documented like this.

I agree that would be useful.
That's certainly something the entire community could help with.

-- F.

[Alex Hough]

I think a feature like filtering should be included on TiddlyWiki.com
if it is a feature that has been included in the core. It would best
belong with content on lists. To my mind it would naturally belong on
under the content section of the features Tiddler[1]

I think it would be better for TW users to be able to use the simple
built in core macros at first, then use a plugin if it didn't meet
their needs. But if they don't know about it they are going to ask the
group then use the excellently documented filtering plugins.

The TW community has no control over TiddlyWiki.com, and can only make
suggestions. Also a user who is learning about computer coding and
finds it difficult to understand documentation. It gets difficult when
the documentation has quotes and there is no way of understanding what
the text in the documentation means. This is not the person to write
the documentation.

The role a non-technical user *is* able to perform is a tester and
questioner, and in his own way help to improve the whole project,
making it easier for new visitors. On TW.org, some of my confusion was
caused by how the information is presented - the meaning the
characters "<+|->" in "[filter[<+|->value]]" .I read it as the
acceptable characters are "less than", "Plus", "Or", "Minus" ,
"greater than" a particular value.

My trial and errors and Erics documentation for his enhancement did
not help much. It seems to me "-" does not work in sorting that it
doesn't work and i get errors. I spent an hour of so messing with it
and could easiliy spend a couple more and still get nowhere on this
decoding of documentation through trying to see what works. That there
is a possibility that it doesn't work contributes to the decision to
use a plugin - probably fET. But there is a risk. What if fET stops
working? Udo has not written many plugins recently and there is no
reason to expect that an updated version would be available. Sunk
costs [1] in learning how to do something are something that I am
becoming aware of as I walk the non-linear TW path to enlightenment.

The radical proposal would of course be to include Erics core in the
core, and to use his documentation. It seems to me that an hour
playing with the built in filter, you would want the functions that
Eric has provided anyway, OR and AND for example.

Alex

[1] http://tiddlywiki.com/#Features
[2] http://en.wikipedia.org/wiki/Sunk_cost



2009/6/29 FND <FN...@gmx.net>:

--
http://www.multiurl.com/g/64

[FND]

> I think a feature like filtering should be included on TiddlyWiki.com

> [...]

> The TW community has no control over TiddlyWiki.com, and can only make
> suggestions.

See these recent messages (sadly buried in an largely unrelated thread):
http://groups.google.com/group/TiddlyWiki/browse_thread/thread/1d0441583c2534c3/eee861fc76ea2007?#eee861fc76ea2007
http://groups.google.com/group/TiddlyWiki/browse_thread/thread/1d0441583c2534c3/b7fbefa589ba0aa7?#b7fbefa589ba0aa7

-- F.