add full fledged HTTP client

dashjoin-core/src/main/java/org/dashjoin/function/Credentials.java

@@ -0,0 +1,31 @@
+package org.dashjoin.function;
+
+import org.dashjoin.model.JsonSchema;
+
+/**
+ * allows storing credentials for OpenJson etc.
+ */
+public class Credentials extends AbstractConfigurableFunction<Void, Void> {
+
+  /**
+   * optional HTTP basic authentication user name
+   */
+  @JsonSchema(style = {"width", "400px"})
+  public String username;
+
+  /**
+   * optional HTTP basic authentication password
+   */
+  @JsonSchema(widget = "password", style = {"width", "400px"})
+  public String password;
+
+  @Override
+  public Void run(Void arg) throws Exception {
+    return null;
+  }
+
+  @Override
+  public Class<Void> getArgumentClass() {
+    return Void.class;
+  }
+}

dashjoin-core/src/main/resources/META-INF/services/org.dashjoin.function.Function

@@ -11,6 +11,7 @@ org.dashjoin.expression.ExpressionService$Traverse
 org.dashjoin.expression.ExpressionService$Incoming
 org.dashjoin.expression.ExpressionService$Call
 org.dashjoin.function.Email
+org.dashjoin.function.Credentials
 org.dashjoin.function.RestJson
 org.dashjoin.function.ConsoleLog
 org.dashjoin.function.CollectMetadata

dashjoin-docs/docs/developer-reference.md

@@ -449,6 +449,15 @@ Return value
 
 * expression result
 
+#### Credentials
+
+Allows saving credentials that can be references by other functions.
+
+Configuration:
+
+* username: credential username
+* password: credential password
+
 ### Mapping Functions
 
 Mapping functions are specialized functions that have no invocation parameters and outputs.
@@ -723,6 +732,7 @@ streamJson | $streamJson(url, jsonPointer) | Parses JSON at the url and splits i
 streamXml | $streamXml(url, jsonPointer) | Parses XML at the url, converts it to JSON, and splits it at the [json pointer](https://datatracker.ietf.org/doc/html/rfc6901) location
 streamCsv | $streamCsv(url, options) | Parses CSV at the url and splits it at the record boundaries. By default, CSV is parsed as RFC4180. Options can be provided, where the key is a "with" method like withDelimiter and the value is the argument. Please see the [documentation](https://commons.apache.org/proper/commons-csv/apidocs/org/apache/commons/csv/CSVFormat.html) for more details.
 streamDb | $streamDb(database, table) | Streams records from the database table specified
+curl | $curl(method, url, data?, headers?) | Full fledged HTTP client. Use {"Authorization": credential} to reference a credential set defined in functions
 openJson | $openJson(url) | Parses JSON at the url
 openCsv | $openCsv(url, options) | Parses CSV at the url and converts it to JSON. By default, CSV is parsed as RFC4180. Options can be provided, where the key is a "with" method like withDelimiter and the value is the argument. Please see the [documentation](https://commons.apache.org/proper/commons-csv/apidocs/org/apache/commons/csv/CSVFormat.html) for more details.
 openXml | $openXml(url, arrays) | Parses XML at the url and converts it to JSON. In this process, openXml guesses which XML tags need to be converted to arrays and which become simple fields. This process might produce inconsistent results when the XML tree contains lists with single entries. To avoid this, you can optionally pass a list of tag names that must be arrays.