format_url

This page explains how to use the format_url function in APL.

The format_url function constructs a properly formatted URL from a dynamic object containing URL components (scheme, host, path, port, etc.). Use this function when you need to build URLs programmatically from parsed components or when reconstructing URLs from log data.

Usage

Syntax

APL

format_url(url_parts)

Parameters

Name	Type	Required	Description
url_parts	dynamic	Yes	A dynamic object containing URL components: scheme, host, path, port, fragment, user, password, query.

Returns

Returns a properly formatted URL string constructed from the provided components.

Use case examples

Reconstruct full URLs from parsed components to analyze complete request patterns.

Query

APLRun in Playground

['sample-http-logs']
| extend full_url = format_url(dynamic({'scheme': 'https', 'host': 'api.example.com', 'path': uri}))
| project _time, method, status, full_url
| limit 10

Output

_time	method	status	full_url
2024-11-06T10:00:00Z	GET	200	`https://api.example.com/api/users`
2024-11-06T10:01:00Z	POST	201	`https://api.example.com/api/orders`
2024-11-06T10:02:00Z	GET	200	`https://api.example.com/api/products`

This query reconstructs full URLs from URI paths by adding the scheme and host, useful for generating clickable links in reports.

Build URLs from trace attributes to identify the full endpoints being called.

Query

APLRun in Playground

['otel-demo-traces']
| extend service_url = format_url(dynamic({'scheme': 'http', 'host': 'localhost', 'port': 8080, 'path': strcat('/', ['service.name'])}))
| project _time, ['service.name'], service_url, trace_id
| limit 10

Output

_time	service.name	service_url	trace_id
2024-11-06T10:00:00Z	frontend	`http://localhost:8080/frontend`	abc123
2024-11-06T10:01:00Z	checkout	`http://localhost:8080/checkout`	def456
2024-11-06T10:02:00Z	cart	`http://localhost:8080/cart`	ghi789

This query constructs service URLs from trace data, helping visualize the actual endpoints in a distributed system.

Construct URLs with authentication parameters to audit access attempts.

Query

APLRun in Playground

['sample-http-logs']
| extend access_url = format_url(dynamic({'scheme': 'https', 'host': 'secure.example.com', 'path': uri, 'user': id}))
| project _time, access_url, status, ['geo.country']
| limit 10

Output

_time	access_url	status	geo.country
2024-11-06T10:00:00Z	https://user123@secure.example.com/admin	403	United States
2024-11-06T10:01:00Z	https://user456@secure.example.com/api/secret	401	Unknown

This query constructs complete URLs including user information for failed authentication attempts, helping security teams understand the full context of access attempts.

parse_url: Parses a URL string into its components. Use this to reverse the formatting operation and extract URL parts.
parse_urlquery: Parses URL query parameters. Use this when you need to work with query string parameters specifically.
url_encode: Encodes a string for safe use in URLs. Use this to encode individual URL components before formatting.
strcat: Concatenates strings. Use this for simple URL construction without the structure of format_url.

format_url

Usage

Syntax

Parameters

Returns

Use case examples

List of related functions

Other query languages