New "else" prefix for filters (#3558)

* Experimental "else" prefix for filters

See #3557

* Docs updates for "else" filter runs
logging-improvements
Jeremy Ruston 2018-11-20 13:29:44 +00:00 zatwierdzone przez GitHub
rodzic 02f26d94a1
commit 09330968cc
Nie znaleziono w bazie danych klucza dla tego podpisu
ID klucza GPG: 4AEE18F83AFDEB23
3 zmienionych plików z 21 dodań i 5 usunięć

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@ -119,7 +119,7 @@ exports.parseFilter = function(filterString) {
p = 0, // Current position in the filter string
match;
var whitespaceRegExp = /(\s+)/mg,
operandRegExp = /((?:\+|\-)?)(?:(\[)|(?:"([^"]*)")|(?:'([^']*)')|([^\s\[\]]+))/mg;
operandRegExp = /((?:\+|\-|~)?)(?:(\[)|(?:"([^"]*)")|(?:'([^']*)')|([^\s\[\]]+))/mg;
while(p < filterString.length) {
// Skip any whitespace
whitespaceRegExp.lastIndex = p;
@ -259,6 +259,13 @@ exports.compileFilter = function(filterString) {
results.splice(0,results.length);
$tw.utils.pushTop(results,operationSubFunction(source,widget));
};
case "~": // This operation is unioned into the result only if the main result so far is empty
return function(results,source,widget) {
if(results.length === 0) {
// Main result so far is empty
$tw.utils.pushTop(results,operationSubFunction(source,widget));
}
};
}
})());
});

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@ -102,6 +102,13 @@ describe("Filter tests", function() {
// Our tests
it("should handle the ~ prefix", function() {
expect(wiki.filterTiddlers("[modifier[JoeBloggs]] ~[[No such tiddler]]").join(",")).toBe("TiddlerOne");
expect(wiki.filterTiddlers("[modifier[JaneBloggs]] ~[[No such tiddler]]").join(",")).toBe("No such tiddler");
expect(wiki.filterTiddlers("~[[No such tiddler]]").join(",")).toBe("No such tiddler");
expect(wiki.filterTiddlers("[my-field[present]] ~[[No such tiddler]]").join(",")).toBe("No such tiddler");
});
it("should handle the lookup operator", function() {
expect(wiki.filterTiddlers("Six Seventh 8 +[lookup[Tiddler]]").join(",")).toBe("Missing inaction from TiddlerOne,,Tidd");
expect(wiki.filterTiddlers("Six Seventh 8 +[lookup:8[Tiddler]]").join(",")).toBe("Missing inaction from TiddlerOne,Tidd,Tidd");

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@ -1,5 +1,5 @@
created: 20150124182421000
modified: 20171212073225103
modified: 20181120125803533
tags: [[Filter Syntax]]
title: Filter Expression
type: text/vnd.tiddlywiki
@ -7,7 +7,7 @@ type: text/vnd.tiddlywiki
<$railroad text="""
[{:
[: [[whitespace|"Filter Whitespace"]] ]
("+"|:-|"-")
("+"|"~"|:-|"-")
[[run|"Filter Run"]]
}]
"""/>
@ -19,6 +19,7 @@ If a run has:
* no prefix, its output titles are [[dominantly appended|Dominant Append]] to the filter's output
* the prefix `-`, output titles are <<.em removed>> from the filter's output (if such tiddlers exist)
* the prefix `+`, it receives the filter output so far as its input; its output then <<.em "replaces">> all filter ouput so far and forms the input for the next run
* <<.from-version "5.1.18">> the prefix `~`, if the filter output so far is an empty list then the output titles of the run are [[dominantly appended|Dominant Append]] to the filter's output. If the filter output so far is not an empty list then the run is ignored
In technical / logical terms:
@ -26,11 +27,12 @@ In technical / logical terms:
|`run` |union of sets |... OR run |
|`+run` |intersection of sets |... AND run |
|`-run` |difference of sets |... AND NOT run |
|`~run` |else |... ELSE run |
A run's input is normally a list of all the non-[[shadow|ShadowTiddlers]] tiddler titles in the wiki (in no particular order). But the `+` prefix can change this:
The input of a run is normally a list of all the non-[[shadow|ShadowTiddlers]] tiddler titles in the wiki (in no particular order). But the `+` prefix can change this:
|Prefix|Input|h
|`-` or none| <$link to="all Operator">`[all[]]`</$link> tiddler titles, unless otherwise determined by the first [[filter operator|Filter Operators]]|
|`-`, `~` or none| <$link to="all Operator">`[all[]]`</$link> tiddler titles, unless otherwise determined by the first [[filter operator|Filter Operators]]|
|`+`|the filter output of all previous runs so far|
Precisely because of varying inputs, be aware that both prefixes `-` and `+` do not behave inverse to one another!