# Module:Convert/doc



This module converts a value from one unit of measurement to another. For example:  
- <code></code> → 123 pounds (56 kg)

The module is called using a template—parameters passed to the template are used by this module to control how a conversion is performed. For example, units can be abbreviated (like <code>kg</code>), or displayed as names (like <code>kilogram</code>), and the output value can be rounded to a specified precision. For usage information, see .  

## Templates and modules
Templates that invoke this module are:  
- Template:Convert
- Template:Cvt

The following modules are required:  
- Module:Convert – *(this module)* code to convert units
- Module:Convert/data – unit definitions
- Module:Convert/text – text messages, and parameter names and values

The following modules are optional and are used only if required and if the module exists:  
- Module:Convert/extra – extra (temporary) unit definitions; used if a unit is not found in Module:Convert/data
- Module:ConvertNumeric – code to spell an input value in words (only English is supported; however, see :vi:Module:ConvertNumeric)

For Wikidata support the following modules are required:  
- Module:Convert/wikidata
- Module:Convert/wikidata/data

The following help pages are available:  
- – overview
- – describes error and warning messages; messages link to this page so it is required when the module is copied to another wiki
- – overview of units

A page containing a convert error is added to the following hidden category, providing the page is in a specified namespace (articles, by default):  
- 

Units are defined in the wikitext of the master list of units.  
- Module:Convert/documentation/conversion data – master list of unit definitions
- Module:Convert/makeunits – translates wikitext from the master list to Lua
- Module talk:Convert/makeunits – makeunits results; copy the text to Module:Convert/data

Module:Convert/data is transcluded into every page using the convert module, so experimenting with a new unit in that module would involve a significant overhead. The Module:Convert/extra module is an alternative which is only transcluded on pages with a unit that is not defined in the main data module.  

Module talk:Convert/show lists all unit links so they can be checked.  

## Sandbox
When making a change, copy the current modules to the sandbox pages, then edit the sandbox copies:  

Use the following template to test the results (example <code></code>):  
- Template:Convert/sandbox

Template:Convert/sandbox invokes Module:Convert/sandbox with parameter which causes convert to use the sandbox modules rather than the normal modules.  

The following should be used to test the results of editing the convert modules.  
- Template:Convert/testcases#Sandbox testcases – links to testcases
- Module:Convert/tester – module to run tests by comparing template output with fixed text

It is not necessary to save a testcases page before viewing test results. For example, Template:Convert/testcases/sandbox4 could be edited to change the tests. While still editing that page, paste (without quotes) into the page title box under "Preview page with this template", then click "Show preview".  

## Configuration
The template that invokes this module can define options to configure the module. For example:  
- <code></code>
:Sets the decimal mark to be a comma, and the thousands separator to be a dot.  

Other options, with default values, are:  
- <code>|maxsigfig=14</code> – maximum number of significant figures
- <code>|nscat=0</code> – namespaces (comma separated) in which an error or warning adds a category to the page
- <code>|warnings=0</code> – 0 (zero) disables warnings; 1 shows important warnings; 2 shows all warnings

An option in the template can specify that the sandbox versions of the modules be used. If specified, the text on the -hand side of the equals sign must be the name of the subpage for each sandbox module.  
- <code>|sandbox=sandbox</code> – omit for normal operation

All text used for input parameters and for output messages and categories can be customized. For example, at enwiki the option <code>|lk=on</code> can be used to link each displayed unit to its article. The "<code>lk</code>" and "<code>on</code>" can be replaced with any desired text. In addition, input and output numbers can be formatted and can use digits in the local language. See the translation guide for more information.  

## To do
Document the modules to access Wikidata!  

## Module version history
- Version 1 December 2013
- Version 2 January 2014
- Version 3 April 2014
- Version 4 July 2014
- Version 5 September 2014
- Version 6 November 2014
- Version 7 December 2014
- Version 8 February 2015
- Version 9 February 2015
- Version 10 May 2015
- Version 11 June 2015
- Version 12 August 2015
- Version 13 March 2016
- Version 14 June 2016
- Version 15 September 2016
- Version 16 January 2017
- Version 17 May 2017
- Version 18 July 2017
- Version 19 August 2017
- Version 20 December 2017
- Version 21 January 2018
- Version 22 February 2018
- Version 23 June 2018
- Version 24 May 2019
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