A filter operator is a predefined keyword attached to an individual step of a filter. It defines the particular action of that step.
Important: In general, each first filter step of a filter run not given any input titles receives the output of [all[tiddlers]] as its input.
Table legend:
✓ | ... | Used to mark the most common ones |
! | ... | The column indicates whether an operator allows negation using the ! prefix.For specifics as to each operator's negated output please refer to its documentation |
C | ... | Most steps process the selection of titles that are supplied as their input, but a few construct an entirely new selection instead, as indicated by the last column. A C? indicates it might construct a new selection, depending on usage. For specifics as to each operator's selection creation please refer to its documentation |
The following table lists all core operators:
Operator | Purpose | ✓ | ! |
C |
---|---|---|---|---|
all | find all titles of a fundamental category | ✓ | C? |
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backlinks | find the titles that link to each input title | |||
backtranscludes | find the titles that transclude each input title | |||
charcode | generates string characters from their numeric character codes | |||
contains | filter the input by searching list fields for a value | ! |
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count | count the number of entries in a list | |||
days | filter the input by date | ! |
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duplicateslugs | find titles that yield duplicate slugs | |||
each | select one of each group of input titles by field | |||
eachday | select one of each group of input titles by date | |||
else | if the list of input titles is empty then return a list consisting of a single constant string, otherwise return the original titles | |||
enlist | select titles from the parameter interpreted as a title list | ! |
C |
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field | filter the input by field | ✓ | ! |
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fields | select all field names of the input titles | |||
filter | apply a subfilter to each input title and return the titles that return a non-empty result from the subfilter | ! |
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function | apply a function to the input list, and return the result | |||
get | select all values of a field in the input titles | |||
getindex | select all values of a data property in the input titles | |||
has | filter the input by field existence | ✓ | ! |
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haschanged | filter the input by tiddler modification status | ! |
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indexes | select all data properties of the input titles | |||
is | filter the input by fundamental category | ✓ | ! |
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join | join a list of strings together with the separator S |
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jsonextract | retrieve the JSON string of a property from JSON strings | |||
jsonget | retrieve the value of a property from JSON strings | |||
jsonindexes | retrieve the value of a property from JSON strings | |||
jsonset | set the value of a property in JSON objects | |||
jsontype | retrieve the type of a property from JSON strings | |||
length | returns the number of characters of each item in the list | |||
links | find the titles linked to by each input title | ✓ | ||
list | select titles via a list field | ! |
C |
|
listed | find the titles that list the input titles | |||
lookup | applies a prefix to each input title to yield the title of a tiddler from which the final value is retrieved. With a single parameter, the default field is "text" and the default index is "0". If a second parameter is provided, that becomes the target field or index. | |||
lowercase | returns each item in the list as lowercase | |||
match | returns each item in the list that matches the parameter string | |||
minlength | filter items whose length is greater than or equal to the specified minimum length | |||
range | generate a range of numbers | ! |
C |
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reduce | apply a subfilter to each input title in turn, accumulating a single value | |||
regexp | filter the input by pattern-matched field | ! |
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sameday | filter the input by date | |||
search | filter the input by searching tiddler content | ✓ | ! |
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sentencecase | returns each item in the list with the first letter capitalised | |||
slugify | returns each item in the list in a human-readable form for use in URLs or filenames | |||
split | returns each item in the list split into separate strings according to the specified separator S ; duplicates are not removed |
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splitregexp | returns each item in the list split into separate strings according to the specified regular expression R |
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subfilter | select titles from the parameter interpreted as a filter expression | ! |
C? |
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then | replace input titles by a constant string | |||
title | select a single title | ✓ | ! |
C |
titlecase | returns each item in the list with each word capitalised | |||
transcludes | find the titles transcluded by each input title | ✓ | ||
uppercase | returns each item in the list as uppercase | |||
Order Operators | ||||
after | find which input title follows a specified one | |||
before | find which input title precedes a specified one | |||
bf | same as rest |
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butfirst | same as rest |
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butlast | discard the last N input titles |
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first | select the first N input titles |
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last | select the last N input titles |
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limit | select the first or last N input titles |
✓ | ! |
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next | find which titles in a list field follow the input ones |
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nsort | sort the input by number field | ! |
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nsortcs | sort the input titles by number field, treating upper and lower case as different | ! |
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nth | select the N th input title |
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order | selectively reverse the input list | ✓ | ||
previous | find which titles in a list field precede the input ones |
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rest | discard the first N input titles |
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reverse | reverse the order of the input titles | |||
sort | sort the input by text field | ✓ | ! |
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sortan | sort the input by text field considering them as alphanumerics | ✓ | ! |
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sortcs | sort the input by text field, treating upper and lower case as different | ! |
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sortsub | sort the input by the result of evaluating a subfilter for each item | ! |
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zth | select the Z th input title |
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Listops Operators | ||||
allafter | discard all items except those after the marker | |||
allbefore | discard all items except those before the marker | |||
append | append a range of items from an array to the list | |||
cycle | toggle the titles specified in the first parameter in a cyclical manner | |||
insertafter | insert an item T into a list immediately after an item A |
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insertbefore | insert an item T into a list immediately before an item B |
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move | move marker N places in the list | |||
prepend | prepend a range of items from an array to the list | |||
putafter | move N trailing items after the marker | |||
putbefore | move N trailing items before the marker | |||
putfirst | move N trailing items to the head of the list | |||
putlast | move N leading items to the tail of the list | |||
remove | remove a list of titles specified in the parameter from the input | |||
replace | replace marker with N trailing items | |||
sortby | sort the current list in the order of the list referenced in the parameter | |||
toggle | toggle the title specified in the parameter in the input | |||
unique | remove all duplicate items from the current list | |||
String Operators | ||||
addprefix | extend each input title with a prefix | |||
addsuffix | extend each input title with a suffix | |||
applypatches | applies a set of patches to transform the input | |||
compare | filter the input by comparing each item against the parameter | ! |
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decodebase64 | apply base 64 decoding to a string | |||
decodehtml | apply HTML decoding to a string | |||
decodeuri | apply URI decoding to a string | |||
decodeuricomponent | apply URI component decoding to a string | |||
encodebase64 | apply base 64 encoding to a string | |||
encodehtml | apply HTML encoding to a string | |||
encodeuri | apply URI encoding to a string | |||
encodeuricomponent | apply URI component encoding to a string | |||
enlist-input | select titles by interpreting each input title as a title list | |||
escapecss | apply CSS escaping to a selection of titles through the CSS.escape() method / operation | |||
escaperegexp | escape special characters used in regular expressions | |||
format | format the input string according to one of supported formats | |||
jsonstringify | apply JSON string encoding to a string, see also the similar stringify |
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levenshtein | determine the Levenshtein distance of the input title(s) and a given string | |||
makepatches | returns a set of patches that transform the input to a given string | |||
pad | returns each item in the list padded to the specified length | |||
prefix | filter the input titles by how they start | ! |
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removeprefix | filter the input titles by how they start, deleting that prefix | |||
removesuffix | filter the input titles by how they end, deleting that suffix | |||
search-replace | returns each item in the list, replacing within each title the string specified by the first parameter with the second parameter | |||
sha256 | apply sha256 hash to a string | |||
splitbefore | select a delimited prefix from each input title | |||
stringify | apply JavaScript string encoding to a string, see also the similar jsonstringify |
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substitute | returns each item in the list, replacing within each title placeholders for filters, parameters and variables with their corresponding values | |||
suffix | filter the input titles by how they end | ! |
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trim | returns each item in the list with whitespace, or a given character string, trimmed from the start and/or end | |||
Mathematics Operators | ||||
abs | calculate the absolute value of a list of numbers | |||
acos | calculate the arccosine value (in radians) of a list of numbers | |||
add | treating each input title as a number, add to each the numeric value of the parameter | |||
asin | calculate the arcsine value (in radians) of a list of numbers | |||
atan | calculate the arctangent value (in radians) of a list of numbers | |||
atan2 | returns the angle in the plane (in radians) between the positive x-axis and the ray from (0,0) to the point (x,y), for [Y ]atan2[X ] |
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average | treating each input title as a number, compute their arithmetic mean | |||
ceil | rounds a list of numbers up to the next largest integer | |||
compare | filter the input by comparing each item against the parameter | ! |
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cos | calculate the cosine value of a list of angles (given in radians) | |||
divide | treating each input title as a number, divide it by the numeric value of the parameter | |||
exponential | convert each number to exponential notation with N digits |
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fixed | convert each number to fixed point notation with N digits after the decimal point |
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floor | rounds a list of numbers to the largest integer less than or equal to each number | |||
log | treating each input title as a number, return its logarithm with base equal to the numeric value of the parameter if specified, otherwise base e |
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max | treating each input title as a number, take the maximum of its value and the numeric value of the parameter | |||
maxall | find the largest of a list of numbers | |||
median | treating each input title as a number, compute their median value | |||
min | treating each input title as a number, take the minimum of its value and the numeric value of the parameter | |||
minall | find the smallest of a list of numbers | |||
multiply | treating each input title as a number, multiply it by the numeric value of the parameter | |||
negate | calculate the negation of a list of numbers | |||
power | treating each input title as a number, raise it to the power of the numeric value of the parameter | |||
precision | convert each number to a string with N significant digits |
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product | produce the product of the input numbers | |||
remainder | treating each input title as a number, return the remainder when divided by the numeric value of the parameter | |||
round | rounds a list of numbers to the nearest integer | |||
sign | return -1, 0 or 1 for a list of numbers according to whether each number is negative, zero, or positive | |||
sin | calculate the sine value of a list of angles (given in radians) | |||
standard-deviation | treating each input title as a number, compute their standard-deviation | |||
subtract | treating each input title as a number, subtract from each the numeric value of the parameter | |||
sum | produce the sum of the input numbers | |||
tan | calculate the tangent value of a list of angles (given in radians) | |||
trunc | truncates a list of numbers to their integer part, removing any fractional part | |||
untrunc | rounds a list of numbers to the next integer with largest absolute value, that is, away from zero | |||
variance | treating each input title as a number, compute their variance | |||
Tag Operators | ||||
tag | filter the input by tag | ✓ | ! |
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tagging | find the tiddlers that have the input tags | |||
tags | select all tags of the input tiddlers | |||
untagged | discard any input titles that have tags | ! |
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Special Operators | ||||
commands | select the titles of all the Node.js commands | C |
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deserialize | extract JSON representation of tiddlers from the input strings | |||
deserializers | C |
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editiondescription | select the descriptions of the input editions | |||
editions | select the names of all the TiddlyWiki editions | C |
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getvariable | select all values of variables named in the input titles | |||
modulesproperty | retrieve a module property | |||
modules | select the names of all modules of the input module types | |||
moduletypes | select the names of all TiddlyWiki module types | C |
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plugintiddlers | select all shadow titles in the input plugins | |||
shadowsource | select the plugin titles that contain the input shadows | |||
storyviews | select the names of all the story views | C |
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subtiddlerfields | select all fields present in the selected tiddlers within a plugin | |||
variables | select the names of all the actively defined variables | C |
A typical step is written as [operator[parameter]]
, although not all of the operators need a parameter.
For the exact rules, see Filter Syntax.