diff options
Diffstat (limited to 'vendor/github.com/tomnomnom/linkheader/main.go')
-rw-r--r-- | vendor/github.com/tomnomnom/linkheader/main.go | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/vendor/github.com/tomnomnom/linkheader/main.go b/vendor/github.com/tomnomnom/linkheader/main.go new file mode 100644 index 0000000..6b81321 --- /dev/null +++ b/vendor/github.com/tomnomnom/linkheader/main.go @@ -0,0 +1,151 @@ +// Package linkheader provides functions for parsing HTTP Link headers +package linkheader + +import ( + "fmt" + "strings" +) + +// A Link is a single URL and related parameters +type Link struct { + URL string + Rel string + Params map[string]string +} + +// HasParam returns if a Link has a particular parameter or not +func (l Link) HasParam(key string) bool { + for p := range l.Params { + if p == key { + return true + } + } + return false +} + +// Param returns the value of a parameter if it exists +func (l Link) Param(key string) string { + for k, v := range l.Params { + if key == k { + return v + } + } + return "" +} + +// String returns the string representation of a link +func (l Link) String() string { + + p := make([]string, 0, len(l.Params)) + for k, v := range l.Params { + p = append(p, fmt.Sprintf("%s=\"%s\"", k, v)) + } + if l.Rel != "" { + p = append(p, fmt.Sprintf("%s=\"%s\"", "rel", l.Rel)) + } + return fmt.Sprintf("<%s>; %s", l.URL, strings.Join(p, "; ")) +} + +// Links is a slice of Link structs +type Links []Link + +// FilterByRel filters a group of Links by the provided Rel attribute +func (l Links) FilterByRel(r string) Links { + links := make(Links, 0) + for _, link := range l { + if link.Rel == r { + links = append(links, link) + } + } + return links +} + +// String returns the string representation of multiple Links +// for use in HTTP responses etc +func (l Links) String() string { + if l == nil { + return fmt.Sprint(nil) + } + + var strs []string + for _, link := range l { + strs = append(strs, link.String()) + } + return strings.Join(strs, ", ") +} + +// Parse parses a raw Link header in the form: +// <url>; rel="foo", <url>; rel="bar"; wat="dis" +// returning a slice of Link structs +func Parse(raw string) Links { + var links Links + + // One chunk: <url>; rel="foo" + for _, chunk := range strings.Split(raw, ",") { + + link := Link{URL: "", Rel: "", Params: make(map[string]string)} + + // Figure out what each piece of the chunk is + for _, piece := range strings.Split(chunk, ";") { + + piece = strings.Trim(piece, " ") + if piece == "" { + continue + } + + // URL + if piece[0] == '<' && piece[len(piece)-1] == '>' { + link.URL = strings.Trim(piece, "<>") + continue + } + + // Params + key, val := parseParam(piece) + if key == "" { + continue + } + + // Special case for rel + if strings.ToLower(key) == "rel" { + link.Rel = val + } else { + link.Params[key] = val + } + } + + if link.URL != "" { + links = append(links, link) + } + } + + return links +} + +// ParseMultiple is like Parse, but accepts a slice of headers +// rather than just one header string +func ParseMultiple(headers []string) Links { + links := make(Links, 0) + for _, header := range headers { + links = append(links, Parse(header)...) + } + return links +} + +// parseParam takes a raw param in the form key="val" and +// returns the key and value as seperate strings +func parseParam(raw string) (key, val string) { + + parts := strings.SplitN(raw, "=", 2) + if len(parts) == 1 { + return parts[0], "" + } + if len(parts) != 2 { + return "", "" + } + + key = parts[0] + val = strings.Trim(parts[1], "\"") + + return key, val + +} |