gg_fnvars

Function Variables

Expression engine for variables to solve at runtime.

This is useful when you need a dynamic value in template engines or text expressions.

Example: "This is a RND number with 3 digits: <var>rnd|number|3</var>"

func TestSolveAll(t *testing.T) {
	statements := []string{
		"this is a random string: (<var>rnd:alphanumeric:6</var>)",
		"this is a random number: (<var>rnd:numeric:6</var>)",
		"this is a random string LOWERCASE: (<var>rnd|alphanumeric|6|lower</var>)",
		"this is a random string UPPERCASE: (<var>rnd|alphanumeric|6|upper</var>)",
		"this is a random GUID UPPERCASE: (<var>rnd|guid|upper</var>)",
		"this is a random Num Between: (<var>rnd|between|0-10</var>)",
		"this is a random ID: (<var>rnd|id</var>)",
		"this is a DateTime: (<var>date|yyyy-MM-dd HH:mm|upper</var>)",
		"this is a DateTime ISO86001: (<var>date|iso|upper</var>)",
		"this is a DateTime Unix: (<var>date|unix</var>)",
		"this is a DateTime Ruby: (<var>date|ruby</var>)",
	}
	engine := gg.FnVars.NewEngine()
	for i, statement := range statements {
		text, err := engine.SolveText(statement)
		if nil != err {
			t.Error(err)
			t.FailNow()
		}
		fmt.Println(i, statement, text)
	}

}

Expressions Syntax

Function Variables are cosed in <var> tags.

Example: <var>rnd</var>

Each Function Variable can have some "options". Options are "optional" data that allow a Function Variable to handle parametrization.

For example, if we need a 3 digits number we can write a Function Variable like this: <var>rnd|numeric|3</var>.

Here is Function Variable explanation:

• rnd: Function Variable name
• numeric: Option telling the engine to extract a number
• 3: Option telling the engine that the number should have 3 digits