[DOCS] Reformat condition token filter

docs/reference/analysis/tokenfilters/condition-tokenfilter.asciidoc

@@ -1,88 +1,148 @@
 [[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
-only applies the subfilters to the current token if it matches the predicate.
+Applies a set of token filters to tokens that match conditions in a provided
+predicate script.
 
-[float]
-=== Options
-[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.
+This filter uses Lucene's
+https://lucene.apache.org/core/{lucene_version_path}/analyzers-common/org/apache/lucene/analysis/miscellaneous/ConditionalTokenFilter.html[ConditionalTokenFilter].
 
-script:: a predicate script that determines whether or not the filters will be applied
-  to the current token.  Note that only inline scripts are supported
+[[analysis-condition-analyze-ex]]
+==== Example
 
-[float]
-=== Settings example
-
-You can set it up like:
+The following <<indices-analyze,analyze API>> request uses the `condition`
+filter to match tokens with fewer than 5 characters in `THE QUICK BROWN FOX`.
+It then applies the <<analysis-lowercase-tokenfilter,`lowercase`>> filter to
+those matching tokens, converting them to lowercase.
 
 [source,console]
 --------------------------------------------------
-PUT /condition_example
+GET /_analyze
 {
-    "settings" : {
-        "analysis" : {
-            "analyzer" : {
-                "my_analyzer" : {
-                    "tokenizer" : "standard",
-                    "filter" : [ "my_condition" ]
-                }
-            },
-            "filter" : {
-                "my_condition" : {
-                    "type" : "condition",
-                    "filter" : [ "lowercase" ],
-                    "script" : {
-                        "source" : "token.getTerm().length() < 5"  <1>
-                    }
-                }
-            }
-        }
+  "tokenizer": "standard",
+  "filter": [
+    {
+      "type": "condition",
+      "filter": [ "lowercase" ],
+      "script": {
+        "source": "token.getTerm().length() < 5"
+      }
     }
+  ],
+  "text": "THE QUICK BROWN FOX"
 }
 --------------------------------------------------
 
-<1> This will only apply the lowercase filter to terms that are less than 5
-characters in length
-
-And test it like:
+The filter produces the following tokens:
 
-[source,console]
+[source,text]
 --------------------------------------------------
-POST /condition_example/_analyze
-{
-  "analyzer" : "my_analyzer",
-  "text" : "What Flapdoodle"
-}
+[ the, QUICK, BROWN, fox ]
 --------------------------------------------------
-// TEST[continued]
-
-And it'd respond:
 
+/////////////////////
 [source,console-result]
 --------------------------------------------------
 {
-  "tokens": [
+  "tokens" : [
+    {
+      "token" : "the",
+      "start_offset" : 0,
+      "end_offset" : 3,
+      "type" : "<ALPHANUM>",
+      "position" : 0
+    },
     {
-      "token": "what",              <1>
-      "start_offset": 0,
-      "end_offset": 4,
-      "type": "<ALPHANUM>",
-      "position": 0
+      "token" : "QUICK",
+      "start_offset" : 4,
+      "end_offset" : 9,
+      "type" : "<ALPHANUM>",
+      "position" : 1
     },
     {
-      "token": "Flapdoodle",        <2>
-      "start_offset": 5,
-      "end_offset": 15,
-      "type": "<ALPHANUM>",
-      "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
     }
   ]
 }
 --------------------------------------------------
+/////////////////////
+
+[[analysis-condition-tokenfilter-configure-parms]]
+==== Configurable parameters
+
+`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.
 
-<1> The term `What` has been lowercased, because it is only 4 characters long
-<2> The term `Flapdoodle` has been left in its original case, because it doesn't pass
-    the predicate
+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"
+          }
+        }
+      }
+    }
+  }
+}
+--------------------------------------------------