[Improve][core] Add CheckUDFContextUtil for verifying UDF configurations. Rename lookup_fields and output_fields to lookupFields and outputFields.

2 files changed, 10 insertions, 9 deletions

diff --git a/docs/develop-guide.md b/docs/develop-guide.md
index 75e8803..927d2d3 100644
--- a/docs/develop-guide.md
+++ b/docs/develop-guide.md
@@ -21,7 +21,7 @@ Groot Stream based all stream processing on data records common known as events.
 ```json
 {
   "__timestamp": "<Timestamp in UNIX epoch format (milliseconds)>",
-  "__input_id": "ID/Name of the source that delivered the event",
+  "__headers":  "Map<String, String> headers of the source that delivered the event",
   "__window_start_timestamp" : "<Timestamp in UNIX epoch format (milliseconds)>",
   "__window_end_timestamp" : "<Timestamp in UNIX epoch format (milliseconds)>",
   "key1": "<value1>",
@@ -35,7 +35,7 @@ Groot Stream add internal fields during pipeline processing. A few notes about i
 - Treat internal fields as read-only. Modifying them can result in unintended consequences to your data flows.
 - Internal fields only exist for the duration of the event processing pipeline. They are not documented under sources or sinks. 
 - If you do not configure a timestamp for extraction, the Pipeline process assigns the current time (in UNIX epoch format) to the __timestamp field.
-- If you have multiple sources, you can determine which source the event came form by looking at the `__input_id` field. For example, the Kafka source adds the topic name to the `__input_id` field.
+- If you have multiple sources, you can determine the origin of the event by examining the `__headers` field. For example, the Kafka source appends the topic name as the `__input_id` key in the `__headers`.
 
 ## How to write a high quality Git commit message
 
diff --git a/docs/processor/udf.md b/docs/processor/udf.md
index 0475192..e480275 100644
--- a/docs/processor/udf.md
+++ b/docs/processor/udf.md
@@ -96,18 +96,19 @@ Base64 encode function is commonly used to encode the binary data to base64 stri
 
 ```BASE64_ENCODE_TO_STRING(filter, output_fields[, parameters])```
 - filter: optional
-- lookup_fields: not required
+- lookup_fields: required
 - output_fields: required
 - parameters: required
-  - value_field: `<String>` required.
+    - input_type: `<String>` required. Enum: `string`, `byte_array`. The input type of the value field.
 
 Example:
 
 ```yaml
 - function: BASE64_ENCODE_TO_STRING
+  lookup_fields: [packet]
   output_fields: [packet]
   parameters:
-    value_field: packet
+    input_type: string
 ```
 
 ### Current Unix Timestamp
@@ -141,7 +142,7 @@ Domain function is used to extract the domain from the url.
 - parameters: required
   - option: `<String>` required. Enum: `TOP_LEVEL_DOMAIN`, `FIRST_SIGNIFICANT_SUBDOMAIN`.
 
-#### Option
+**Option**
 
 - `TOP_LEVEL_DOMAIN` is used to extract the top level domain from the url. For example, `www.abc.com` will be extracted to `com`.
 - `FIRST_SIGNIFICANT_SUBDOMAIN` is used to extract the first significant subdomain from the url. For example, `www.abc.com` will be extracted to `abc.com`.
@@ -283,7 +284,7 @@ From unix timestamp function is used to convert the unix timestamp to date time
 - parameters: optional
   - precision: `<String>` optional. Default is `seconds`. Enum: `milliseconds`, `seconds`.
 
-#### Precision
+**Precision**
 
 - `milliseconds` is used to convert the unix timestamp to milliseconds date time string. For example, `1619712000` will be converted to `2021-04-30 00:00:00.000`.
 - `seconds` is used to convert the unix timestamp to seconds date time string. For example, `1619712000` will be converted to `2021-04-30 00:00:00`.
@@ -336,7 +337,7 @@ GeoIP lookup function is used to lookup the geoip information by ip address. You
     - ISP: `<String>` optional.
     - ORGANIZATION: `<String>` optional.
 
-#### Option
+**Option**
 
 - `IP_TO_COUNTRY` is used to lookup the country or region information by ip address.
 - `IP_TO_PROVINCE` is used to lookup the province or state information by ip address.
@@ -348,7 +349,7 @@ GeoIP lookup function is used to lookup the geoip information by ip address. You
 - `IP_TO_JSON` is used to lookup the above information by ip address. The result is a json string.
 - `IP_TO_OBJECT` is used to lookup the above information by ip address. The result is a `LocationResponse` object.
 
-#### GeoLocation Field Mapping
+**GeoLocation Field Mapping**
 
 - `COUNTRY` is used to map the country information to the event field.
 - `PROVINCE` is used to map the province information to the event field.