HOST Function

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Finds the host value from a valid URL. Input values must be of URL or String type and can be literals or column references.In this implementation, a host value includes everything from the end of the protocol identifier (if present) to the end of the extension (e.g. .com).

For more information, see Structure of a URL.

Basic Usage

URL literal examples:

derive type:single value: HOST('http://www.example.com' ) as: 'myHost'

Output: Generates a column containing the value www.example.com.

Column reference example:

derive type:single value: HOST(myURLs) as: 'myHost'

Output: Generates the new myHost column containing the host values extracted from the myURLs column.

Syntax and Arguments

derive type:single value: HOST(column_url)

Argument	Required?	Data Type	Description
column_url	Y	string	Name of column or String or URL literal containing the host value to extract

For more information on syntax standards, see Language Documentation Syntax Notes.

column_url

Name of the column or URL or String literal whose values are used to extract the host value.

Missing input values generate missing results.
Multiple columns and wildcards are not supported.

Usage Notes:

Required?	Data Type	Example Value
Yes	String literal or column reference (URL)	`http://www.example.com`

Examples

Tip: For additional examples, see Common Tasks.

Example - Domain, Host, Subdomain, and Suffix functions

This examples illustrates how you can extract component parts of a URL using the following functions:

DOMAIN - extracts the domain value from a URL. See DOMAIN Function.
SUBDOMAIN - extracts the first group after the protocol identifier and before the domain value. See SUBDOMAIN Function.
HOST - returns the complete value of the host from an URL. See HOST Function.
SUFFIX - extracts the suffix of a URL. See SUFFIX Function.
URLPARAMS - extracts the query parameters and values from a URL. See URLPARAMS Function.
FILTEROBJECT - filters an Object value to show only the elements for a specified key. See FILTEROBJECT Function.

Source:

Your dataset includes the following values for URLs:

URL
www.example.com
example.com/support
http://www.example.com/products/
http://1.2.3.4
https://www.example.com/free-download
https://www.example.com/about-us/careers
www.app.example.com
www.some.app.example.com
some.app.example.com
some.example.com
example.com
http://www.example.com?q1=broken%20record
http://www.example.com?query=khakis&app=pants
http://www.example.com?q1=broken%20record&q2=broken%20tape&q3=broken%20wrist

Transform:

When the above data is imported into the application, the column is recognized as a URL. All values are registered as valid, even the IPv4 address.

To extract the domain and subdomain values:

derive type:single value: DOMAIN(URL) as: 'domain_URL'

derive type:single value: SUBDOMAIN(URL) as:'subdomain_URL'

derive type:single value: HOST(URL) as:host_URL'

derive type:single value: SUFFIX(URL) as:'suffix_URL'

You can use the Alteryx® pattern in the following transform to extract protocol identifiers, if present, into a new column:

extract col:URL on:`{start}%*://`

To clean this up, you might want to rename the column to protocol_URL.

To extract the path values, you can use the following regular expression:

NOTE: Regular expressions are considered a developer-level method for pattern matching. Please use them with caution. See Text Matching.

extract col: URL on: /[^*:\/\/]\/.*$/

The above transform grabs a little too much of the URL. If you rename the column to path_URL, you can use the following regular expression to clean it up:

extract col:path_URL on:/[!^\/].*$/

Drop the path_URL column and rename the path_URL1 column to the dropped one. Then:

derive type:single value: URLPARAMS(URL) as: 'urlParams'

If you wanted to just see the values for the q1 parameter, you could add the following:

derive type:single value: FILTEROBJECT(urlParams,'q1') as: 'urlParam_q1'

Results:

URL	host_URL	path_URL	protocol_URL	subdomain_URL	domain_URL	suffix_URL	urlParams	urlParam_q1
www.example.com	www.example.com			www	example	com
example.com/support	example.com	/support			example	com
http://www.example.com/products/	www.example.com	/products/	http://	www	example	com
http://1.2.3.4	1.2.3.4		http://
https://www.example.com/free-download	www.example.com	/free-download	https://	www	example	com
https://www.example.com/about-us/careers	www.example.com	/about-us/careers	https://	www	example	com
www.app.example.com	www.app.example.com			www.app	example	com
www.some.app.example.com	www.some.app.example.com			www.some.app	example	com
some.app.example.com	some.app.example.com			some.app	example	com
some.example.com	some.example.com			some	example	com
example.com	example.com				example	com
http://www.example.com?q1=broken%20record	www.example.com		http://	www	example	com	{"q1":"broken record"}	{"q1":"broken record"}
http://www.example.com?query=khakis&app=pants	www.example.com		http://	www	example	com	{"query":"khakis","app":"pants"}
http://www.example.com?q1=broken%20record&q2=broken%20tape&q3=broken%20wrist	www.example.com		http://	www	example	com	{"q1":"broken record", "q2":"broken tape", "q3":"broken wrist"}	{"q1":"broken record"}

See Also for HOST Function:

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