Difference between revisions of "Module:Protect/doc"

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blackwiki>Petr Matas
(→‎Example: protect removes location information by itself)
blackwiki>Petr Matas
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Invoking the main function without arguments will output: <strong class="error">Error: missing argument</strong>
 
Invoking the main function without arguments will output: <strong class="error">Error: missing argument</strong>
 
<includeonly>{{#ifeq:{{SUBPAGENAME}}|sandbox | |
 
<includeonly>{{#ifeq:{{SUBPAGENAME}}|sandbox | |
[[Category:Lua metamodules]]
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[[Category:Error-handling modules]]
 
}}</includeonly>
 
}}</includeonly>

Revision as of 10:21, 20 August 2018

This metamodule simplifies error handling in other modules. It transforms a function, which may throw an error, into a function, which returns a specified error message in that case.

Usage

local protect = require('Module:Protect')
local protectedFunc = protect(func, errFormat, options)

Arguments

  • func
    Function to be transformed.
  • errFormat (default: 'Error: %s')
    Custom error message.
    Use '%s' to include the message from a caught error.
  • options – optional table with the following fields:
    • raw (default: false)
      If true, then errFormat will be used as is, otherwise it will be wrapped inside a tag <strong class="error">.
    • removeLocation (default: true)
      If true, removes location information from caught error messages.

Return value

The resulting protectedFunc is a function, which calls the original function func, passing all arguments to it, and returns all its return values. If func throws an error, the specified error message is returned instead.

Example

local protect = require('Module:Protect')

local p = {}

function p.main(frame)
    if not frame.args[1] then
        error('missing argument')
    end
    return frame.args[1]
end

p.main = protect(p.main)

return p

Invoking the main function without arguments will output: Error: missing argument