checkBox

def checkBox = {attrs ->
        attrs.id = attrs.id ? attrs.id : attrs.name
        def value = attrs.remove('value')
        def name = attrs.remove('name')
        def disabled = attrs.remove('disabled')
        if (disabled && Boolean.valueOf(disabled)) {
            attrs.disabled = 'disabled'
        }
        // Deal with the "checked" attribute. If it doesn't exist, we
        // default to a value of "true", otherwise we use Groovy Truth
        // to determine whether the HTML attribute should be displayed
        // or not.
        def checked = true
        if (attrs.containsKey('checked')) {
            checked = attrs.remove('checked')
        }
        if (checked instanceof String) checked = Boolean.valueOf(checked)
        if (value == null) value = false
        // the hidden field name should begin with an underscore unless it is
        // a dotted name, then the underscore should be inserted after the last
        // dot
        def lastDotInName = name.lastIndexOf('.')
        def hiddenFieldName = lastDotInName == -1 ? '_' + name : name[0..lastDotInName] + '_' + name[(lastDotInName+1)..-1]
        out << "<input type=\"hidden\" name=\"${hiddenFieldName}\" /><input type=\"checkbox\" name=\"${name}\" "
        if (value && checked) {
            out << 'checked="checked" '
        }
        def outputValue = !(value instanceof Boolean || value?.class == boolean.class)
        if (outputValue)
            out << "value=\"${value}\" "
        // process remaining attributes
        outputAttributes(attrs)
        // close the tag, with no body
        out << ' />'
    }