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

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

Arguments

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  • 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

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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

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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