[DOCS] Reformat condition token filter (#48775)
This commit is contained in:
James Rodewig
parent
eb0d8f3383
commit
dd92830801
|
|
@ -1,88 +1,148 @@
|
||||||
[[analysis-condition-tokenfilter]]
|
[[analysis-condition-tokenfilter]]
|
||||||
=== Conditional Token Filter
|
=== Conditional token filter
|
||||||
|
++++
|
||||||
|
<titleabbrev>Conditional</titleabbrev>
|
||||||
|
++++
|
||||||
|
|
||||||
The conditional token filter takes a predicate script and a list of subfilters, and
|
Applies a set of token filters to tokens that match conditions in a provided
|
||||||
only applies the subfilters to the current token if it matches the predicate.
|
predicate script.
|
||||||
|
|
||||||
[float]
|
This filter uses Lucene's
|
||||||
=== Options
|
https://lucene.apache.org/core/{lucene_version_path}/analyzers-common/org/apache/lucene/analysis/miscellaneous/ConditionalTokenFilter.html[ConditionalTokenFilter].
|
||||||
[horizontal]
|
|
||||||
filter:: a chain of token filters to apply to the current token if the predicate
|
|
||||||
matches. These can be any token filters defined elsewhere in the index mappings.
|
|
||||||
|
|
||||||
script:: a predicate script that determines whether or not the filters will be applied
|
[[analysis-condition-analyze-ex]]
|
||||||
to the current token. Note that only inline scripts are supported
|
==== Example
|
||||||
|
|
||||||
[float]
|
The following <<indices-analyze,analyze API>> request uses the `condition`
|
||||||
=== Settings example
|
filter to match tokens with fewer than 5 characters in `THE QUICK BROWN FOX`.
|
||||||
|
It then applies the <<analysis-lowercase-tokenfilter,`lowercase`>> filter to
|
||||||
You can set it up like:
|
those matching tokens, converting them to lowercase.
|
||||||
|
|
||||||
[source,console]
|
[source,console]
|
||||||
--------------------------------------------------
|
--------------------------------------------------
|
||||||
PUT /condition_example
|
GET /_analyze
|
||||||
{
|
{
|
||||||
"settings" : {
|
"tokenizer": "standard",
|
||||||
"analysis" : {
|
"filter": [
|
||||||
"analyzer" : {
|
{
|
||||||
"my_analyzer" : {
|
"type": "condition",
|
||||||
"tokenizer" : "standard",
|
"filter": [ "lowercase" ],
|
||||||
"filter" : [ "my_condition" ]
|
"script": {
|
||||||
}
|
"source": "token.getTerm().length() < 5"
|
||||||
},
|
}
|
||||||
"filter" : {
|
|
||||||
"my_condition" : {
|
|
||||||
"type" : "condition",
|
|
||||||
"filter" : [ "lowercase" ],
|
|
||||||
"script" : {
|
|
||||||
"source" : "token.getTerm().length() < 5" <1>
|
|
||||||
}
|
|
||||||
}
|
|
||||||
}
|
|
||||||
}
|
|
||||||
}
|
}
|
||||||
|
],
|
||||||
|
"text": "THE QUICK BROWN FOX"
|
||||||
}
|
}
|
||||||
--------------------------------------------------
|
--------------------------------------------------
|
||||||
|
|
||||||
<1> This will only apply the lowercase filter to terms that are less than 5
|
The filter produces the following tokens:
|
||||||
characters in length
|
|
||||||
|
|
||||||
And test it like:
|
[source,text]
|
||||||
|
|
||||||
[source,console]
|
|
||||||
--------------------------------------------------
|
--------------------------------------------------
|
||||||
POST /condition_example/_analyze
|
[ the, QUICK, BROWN, fox ]
|
||||||
{
|
|
||||||
"analyzer" : "my_analyzer",
|
|
||||||
"text" : "What Flapdoodle"
|
|
||||||
}
|
|
||||||
--------------------------------------------------
|
--------------------------------------------------
|
||||||
// TEST[continued]
|
|
||||||
|
|
||||||
And it'd respond:
|
|
||||||
|
|
||||||
|
/////////////////////
|
||||||
[source,console-result]
|
[source,console-result]
|
||||||
--------------------------------------------------
|
--------------------------------------------------
|
||||||
{
|
{
|
||||||
"tokens": [
|
"tokens" : [
|
||||||
{
|
{
|
||||||
"token": "what", <1>
|
"token" : "the",
|
||||||
"start_offset": 0,
|
"start_offset" : 0,
|
||||||
"end_offset": 4,
|
"end_offset" : 3,
|
||||||
"type": "<ALPHANUM>",
|
"type" : "<ALPHANUM>",
|
||||||
"position": 0
|
"position" : 0
|
||||||
},
|
},
|
||||||
{
|
{
|
||||||
"token": "Flapdoodle", <2>
|
"token" : "QUICK",
|
||||||
"start_offset": 5,
|
"start_offset" : 4,
|
||||||
"end_offset": 15,
|
"end_offset" : 9,
|
||||||
"type": "<ALPHANUM>",
|
"type" : "<ALPHANUM>",
|
||||||
"position": 1
|
"position" : 1
|
||||||
|
},
|
||||||
|
{
|
||||||
|
"token" : "BROWN",
|
||||||
|
"start_offset" : 10,
|
||||||
|
"end_offset" : 15,
|
||||||
|
"type" : "<ALPHANUM>",
|
||||||
|
"position" : 2
|
||||||
|
},
|
||||||
|
{
|
||||||
|
"token" : "fox",
|
||||||
|
"start_offset" : 16,
|
||||||
|
"end_offset" : 19,
|
||||||
|
"type" : "<ALPHANUM>",
|
||||||
|
"position" : 3
|
||||||
}
|
}
|
||||||
]
|
]
|
||||||
}
|
}
|
||||||
--------------------------------------------------
|
--------------------------------------------------
|
||||||
|
/////////////////////
|
||||||
|
|
||||||
<1> The term `What` has been lowercased, because it is only 4 characters long
|
[[analysis-condition-tokenfilter-configure-parms]]
|
||||||
<2> The term `Flapdoodle` has been left in its original case, because it doesn't pass
|
==== Configurable parameters
|
||||||
the predicate
|
|
||||||
|
`filter`::
|
||||||
|
+
|
||||||
|
--
|
||||||
|
(Required, array of token filters)
|
||||||
|
Array of token filters. If a token matches the predicate script in the `script`
|
||||||
|
parameter, these filters are applied to the token in the order provided.
|
||||||
|
|
||||||
|
These filters can include custom token filters defined in the index mapping.
|
||||||
|
--
|
||||||
|
|
||||||
|
`script`::
|
||||||
|
+
|
||||||
|
--
|
||||||
|
(Required, <<modules-scripting-using,script object>>)
|
||||||
|
Predicate script used to apply token filters. If a token
|
||||||
|
matches this script, the filters in the `filter` parameter are applied to the
|
||||||
|
token.
|
||||||
|
|
||||||
|
For valid parameters, see <<_script_parameters>>. Only inline scripts are
|
||||||
|
supported. Painless scripts are executed in the
|
||||||
|
{painless}/painless-analysis-predicate-context.html[analysis predicate context]
|
||||||
|
and require a `token` property.
|
||||||
|
--
|
||||||
|
|
||||||
|
[[analysis-condition-tokenfilter-customize]]
|
||||||
|
==== Customize and add to an analyzer
|
||||||
|
|
||||||
|
To customize the `condition` filter, duplicate it to create the basis
|
||||||
|
for a new custom token filter. You can modify the filter using its configurable
|
||||||
|
parameters.
|
||||||
|
|
||||||
|
For example, the following <<indices-create-index,create index API>> request
|
||||||
|
uses a custom `condition` filter to configure a new
|
||||||
|
<<analysis-custom-analyzer,custom analyzer>>. The custom `condition` filter
|
||||||
|
matches the first token in a stream. It then reverses that matching token using
|
||||||
|
the <<analysis-reverse-tokenfilter,`reverse`>> filter.
|
||||||
|
|
||||||
|
[source,console]
|
||||||
|
--------------------------------------------------
|
||||||
|
PUT /palindrome_list
|
||||||
|
{
|
||||||
|
"settings": {
|
||||||
|
"analysis": {
|
||||||
|
"analyzer": {
|
||||||
|
"whitespace_reverse_first_token": {
|
||||||
|
"tokenizer": "whitespace",
|
||||||
|
"filter": [ "reverse_first_token" ]
|
||||||
|
}
|
||||||
|
},
|
||||||
|
"filter": {
|
||||||
|
"reverse_first_token": {
|
||||||
|
"type": "condition",
|
||||||
|
"filter": [ "reverse" ],
|
||||||
|
"script": {
|
||||||
|
"source": "token.getPosition() === 0"
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
--------------------------------------------------
|
||||||
Loading…
Reference in New Issue