Add documentation for Split SearchRequestProcessor

Signed-off-by: Daniel Widdis <[email protected]>

_ingest-pipelines/processors/split.md

@@ -30,7 +30,7 @@ Parameter  | Required/Optional  | Description
 :--- | :--- | :--- 
 `field` | Required | The field containing the string to be split. 
 `separator` | Required | The delimiter used to split the string. This can be a regular expression pattern. 
-`preserve_field` | Optional | If set to `true`, preserves empty trailing fields (for example, `''`) in the resulting array. If set to `false`, empty trailing fields are removed from the resulting array. Default is `false`. 
+`preserve_trailing` | Optional | If set to `true`, preserves empty trailing fields (for example, `''`) in the resulting array. If set to `false`, empty trailing fields are removed from the resulting array. Default is `false`. 
 `target_field` | Optional | The field where the array of substrings is stored. If not specified, then the field is updated in-place. 
 `ignore_missing` | Optional	| Specifies whether the processor should ignore documents that do not contain the specified field. If set to `true`, then the processor ignores missing values in the field and leaves the `target_field` unchanged. Default is `false`.  
 `description` | Optional | A brief description of the processor. 

_search-plugins/search-pipelines/split-processor.md

@@ -0,0 +1,232 @@
+---
+layout: default
+title: Split
+nav_order: 33
+has_children: false
+parent: Search processors
+grand_parent: Search pipelines
+---
+
+# Split processor
+
+The `split` processor is used to split a string field into an array of substrings based on a specified delimiter.
+
+## Request fields
+
+The following table lists all available request fields.
+
+Field | Data type | Description
+:--- | :--- | :---
+`field` | String | The field containing the string to be split. Required.
+`separator` | String | The delimiter used to split the string. This can be a regular expression pattern. Required.
+`preserve_trailing` | Boolean | If set to `true`, preserves empty trailing fields (for example, `''`) in the resulting array. If set to `false`, empty trailing fields are removed from the resulting array. Default is `false`. 
+`target_field` | String | The field where the array of substrings is stored. If not specified, then the field is updated in-place. 
+`tag` | String | The processor's identifier. 
+`description` | String | A description of the processor. 
+`ignore_failure` | Boolean | If `true`, OpenSearch [ignores any failure]({{site.url}}{{site.baseurl}}/search-plugins/search-pipelines/creating-search-pipeline/#ignoring-processor-failures) of this processor and continues to run the remaining processors in the search pipeline. Optional. Default is `false`.
+
+## Example 
+
+The following example demonstrates using a search pipeline with a `split` processor.
+
+### Setup
+
+Create an index named `my_index` and index a document with the field `message`:
+
+```json
+POST /my_index/_doc/1
+{
+  "message": "ingest, search, visualize, and analyze data",
+  "visibility":"public"
+}
+```
+{% include copy-curl.html %}
+
+### Creating a search pipeline 
+
+The following request creates a search pipeline with a `split` response processor that splits the field `message` in `split_message`:
+
+```json
+PUT /_search/pipeline/my_pipeline
+{
+  "response_processors": [
+    {
+      "split": {
+        "field": "message",
+        "separator": ", ",
+        "target_field": "split_message"
+      }
+    }
+  ]
+}
+```
+{% include copy-curl.html %}
+
+### Using a search pipeline
+
+Search for documents in `my_index` without a search pipeline:
+
+```json
+GET /my_index/_search
+```
+{% include copy-curl.html %}
+
+The response contains the field `message`:
+
+<details open markdown="block">
+  <summary>
+    Response
+  </summary>
+  {: .text-delta}
+```json
+{
+  "took": 3,
+  "timed_out": false,
+  "_shards": {
+    "total": 1,
+    "successful": 1,
+    "skipped": 0,
+    "failed": 0
+  },
+  "hits": {
+    "total": {
+      "value": 1,
+      "relation": "eq"
+    },
+    "max_score": 1,
+    "hits": [
+      {
+        "_index": "my_index",
+        "_id": "1",
+        "_score": 1,
+        "_source": {
+          "message": "ingest, search, visualize, and analyze data",
+          "visibility": "public"
+        }
+      }
+    ]
+  }
+}
+```
+</details>
+
+To search with a pipeline, specify the pipeline name in the `search_pipeline` query parameter:
+
+```json
+GET /my_index/_search?search_pipeline=my_pipeline
+```
+{% include copy-curl.html %}
+
+The `message` field has been split in `split_message`:
+
+<details open markdown="block">
+  <summary>
+    Response
+  </summary>
+  {: .text-delta}
+```json
+{
+  "took": 6,
+  "timed_out": false,
+  "_shards": {
+    "total": 1,
+    "successful": 1,
+    "skipped": 0,
+    "failed": 0
+  },
+  "hits": {
+    "total": {
+      "value": 1,
+      "relation": "eq"
+    },
+    "max_score": 1,
+    "hits": [
+      {
+        "_index": "my_index",
+        "_id": "1",
+        "_score": 1,
+        "_source": {
+          "visibility": "public",
+          "message": "ingest, search, visualize, and analyze data",
+          "split_message": [
+            "ingest",
+            "search",
+            "visualize",
+            "and analyze data"
+          ]
+        }
+      }
+    ]
+  }
+}
+```
+</details>
+
+You can also use the `fields` option to search for specific fields in a document:
+
+```json
+POST /my_index/_search?pretty&search_pipeline=my_pipeline
+{
+    "fields":["visibility", "message"]
+}
+``` 
+{% include copy-curl.html %}
+
+In the response, the field `message` has been split to `sorted_message`:
+
+<details open markdown="block">
+  <summary>
+    Response
+  </summary>
+  {: .text-delta}
+```json
+{
+  "took": 7,
+  "timed_out": false,
+  "_shards": {
+    "total": 1,
+    "successful": 1,
+    "skipped": 0,
+    "failed": 0
+  },
+  "hits": {
+    "total": {
+      "value": 1,
+      "relation": "eq"
+    },
+    "max_score": 1,
+    "hits": [
+      {
+        "_index": "my_index",
+        "_id": "1",
+        "_score": 1,
+        "_source": {
+          "visibility": "public",
+          "message": "ingest, search, visualize, and analyze data",
+          "split_message": [
+            "ingest",
+            "search",
+            "visualize",
+            "and analyze data"
+          ]
+        },
+        "fields": {
+          "visibility": [
+            "public"
+          ],
+          "message": [
+            "ingest, search, visualize, and analyze data"
+          ],
+          "split_message": [
+            "ingest",
+            "search",
+            "visualize",
+            "and analyze data"
+          ]
+        }
+      }
+    ]
+  }
+}
+```
+</details>