http?

Written as http?(argnum flags):options in a transform expression.

Minimum arguments	1
Maximum arguments	1
Default arguments	1
Argument modes	SINGLE_PRIMITIVE

Documentation

Extract a specific query parameter from a URL.

Features:

• Extracts the value of a named query parameter
• Returns None if the parameter doesn’t exist
• Handles both encoded and unencoded parameter names/values
• Preserves the original encoding of the parameter value

Behavior:

• Only extracts the first occurrence if multiple parameters with same name exist
• Returns the raw parameter value without additional decoding/encoding
• Case-sensitive parameter name matching

Flags

Flag	Letter
noncaptive_input	I

Examples

Basic parameter extraction

Input args: ["https://example.com/search?q=hello&lang=en"]
Transforms: "http?:q"
Output: "hello"

Non-existent parameter

Input args: ["https://example.com/search?q=hello"]
Transforms: "http?:page"
Output: null

Encoded parameter name

Input args: ["https://example.com?%24filter=name%3Djohn"]
Transforms: "http?:$filter"
Output: "name=john"

Multiple parameters

Input args: ["https://example.com?color=red&color=blue"]
Transforms: "http?:color"
Output: "blue"

Empty parameter value

Input args: ["https://example.com?empty=&full=value"]
Transforms: "http?:empty"
Output: ""