lsem_equations: Building LimeSurvey Expression Manager equations

In limonaid: Working with 'LimeSurvey' Surveys and Responses

Building LimeSurvey Expression Manager equations

Description

These are a set of really basic functions that facilitate building LimeSurvey Expression Manager (LSEM) equations.

Usage

ls_eq_build(lhs, operator, rhs)

ls_eq_is(varCode, value, naok = TRUE)

ls_eq_isChecked(varCode, naok = TRUE)

ls_eq_isUnchecked(varCode, naok = TRUE)

ls_eq_if(cond, ifExpr, elseExpr)

ls_eq_ifRegex(regex, varCode, ifExpr, elseExpr, naok = TRUE)

ls_eq_brace(expr)

ls_eq_quote(expr)

Arguments

lhs	The left-hand side expression.
operator	The operator.
rhs	The right-hand side expression.
varCode	A LimeSurvey variable code.
value	A value.
naok	Whether to append ".NAOK" to the variable code.
cond	A condition, for example created by ls_eq_build() or ls_eq_is().
ifExpr, elseExpr, expr	An expression.
regex	A regular expression.

Details

ls_eq_build() just pastes together its three arguments in the same order using a space as separator. So it's mostly used for clarity when building LSEM equations.

ls_eq_is() uses ls_eq_build() to specify a logical expression that is true when varCode equals value.

ls_eq_if() builds an if/then/else expression; if cond evaluates to TRUE, the LSEM uses ifExpr; otherwise, it uses elseExpr.

ls_eq_ifRegex checks a question against a regular expression.

ls_eq_isChecked() and ls_eq_isUnchecked() return an expression evaluating whether a checkbox is checked (or not).

ls_eq_brace() simply embraces expr, an expression (i.e. it prepends ⁠{⁠ and appends ⁠}⁠).

ls_eq_quote() simply embraces expr, an expression (i.e. it prepends ⁠'⁠ and appends ⁠'⁠).

Value

A character vector.

Examples

ls_eq_build("questionCode", "==", "Y");

limonaid documentation built on June 10, 2025, 9:10 a.m.