// FilterFunc Filter out Values that match specified list of match filter criteria
//
// - Operates on MapValue (map[string]interface{}), StringsValue ([]string), or string
// - takes N Filter Criteria
// - supports Matching: "filter*" // matches "filter_x", "filterstuff"
//
// -- Filter a map of values by key to remove certain keys
// filter(match("topic_"),key_to_filter, key2_to_filter) => {"goodkey": 22}, true
//
// -- Filter out VALUES (not keys) from a list of []string{} for a specific value
// filter(split("apples,oranges",","),"ora*") => ["apples"], true
//
// -- Filter out values for single strings
// filter("apples","app*") => []string{}, true
//
func FilterFunc(ctx expr.EvalContext, val value.Value, filterVals ...value.Value) (value.Value, bool) {
filters := FiltersFromArgs(filterVals)
//u.Debugf("Filter(): %T:%v filters:%v", val, val, filters)
switch val := val.(type) {
case value.MapValue:
mv := make(map[string]interface{})
for rowKey, v := range val.Val() {
filteredOut := false
for _, filter := range filters {
if strings.Contains(filter, "*") {
match, _ := glob.Match(filter, rowKey)
if match {
filteredOut = true
break
}
} else {
if strings.HasPrefix(rowKey, filter) && v != nil {
filteredOut = true
break
}
}
}
if !filteredOut {
mv[rowKey] = v.Value()
}
}
return value.NewMapValue(mv), true
case value.StringValue:
anyMatches := false
for _, filter := range filters {
if strings.Contains(filter, "*") {
match, _ := glob.Match(filter, val.Val())
if match {
anyMatches = true
break
}
} else {
if strings.HasPrefix(val.Val(), filter) {
anyMatches = true
break
}
}
}
if anyMatches {
return value.NilValueVal, true
}
return val, true
case value.StringsValue:
lv := make([]string, 0, val.Len())
for _, sv := range val.Val() {
filteredOut := false
for _, filter := range filters {
if strings.Contains(filter, "*") {
match, _ := glob.Match(filter, sv)
if match {
filteredOut = true
break
}
} else {
if strings.HasPrefix(sv, filter) && sv != "" {
filteredOut = true
break
}
}
}
if !filteredOut {
lv = append(lv, sv)
}
}
return value.NewStringsValue(lv), true
default:
u.Warnf("unsuported key type: %T %v", val, val)
}
//u.Warnf("could not find key: %T %v", item, item)
return nil, false
}
