Lua Code Basics

Below is a description of patterns and magic characters used in Lua.
Some of the information below was gathered from: http://www.lua.org/pil/20.2.html

Setting a variable equal to something: =
Variables are declared by using the word "local".
Example:

local myVariableName = "this can be a string, number, array";

Concatenation (joining characters and strings together: ..
Example:

local myString = "This is " .. "the best string ever.";

Equality test (is equal to): ==
Example test:

local Author = "Bill Jones";
local transactionAuthor = GetFieldValue("Transaction", "LoanAuthor");

if Author == transactionAuthor then
  interfaceMngr:ShowMessage("The Author is Bill Jones", "Transaction Information");
else
  interfaceMngr:ShowMessage("The Author is not Bill Jones", "Transaction Information");
end

Inequality test (is not equal to): ~=
In this example, we are setting a variable called author to act as a placeholder for LoanAuthor or PhotoArticleAuthor.

local transactionType = GetFieldValue("Transaction", "RequestType");
local author = "";

if transactionType ~= "Loan" then
  author = GetFieldValue("Transaction", "PhotoArticleAuthor");
else
  author = GetFieldValue("Transaction", "LoanAuthor");
end

Magic Characters (These characters have specific functions, but the characters can be escaped by using an escape character.
( ) . % + - * ? [ ^ $

Escape Characters
% for escaping magic characters
\ for everything else

Character classes:
. all characters
%a letters
%c control characters
%d digits
%l lower case letters
%p punctuation characters
%s space characters
%u upper case letters
%w alphanumeric characters
%x hexadecimal digits
%z the character with representation 0