newRouteRegexp parses a route template and returns a routeRegexp, used to match a host, a path or a query string. It will extract named variables, assemble a regexp to be matched, create a "reverse" template to build URLs and compile regexps to validate variable values used in URL building. Previo
(tpl string, typ regexpType, options routeRegexpOptions)
| 39 | // names ([a-zA-Z_][a-zA-Z0-9_]*), but currently the only restriction is that |
| 40 | // name and pattern can't be empty, and names can't contain a colon. |
| 41 | func newRouteRegexp(tpl string, typ regexpType, options routeRegexpOptions) (*routeRegexp, error) { |
| 42 | // Check if it is well-formed. |
| 43 | idxs, errBraces := braceIndices(tpl) |
| 44 | if errBraces != nil { |
| 45 | return nil, errBraces |
| 46 | } |
| 47 | // Backup the original. |
| 48 | template := tpl |
| 49 | // Now let's parse it. |
| 50 | defaultPattern := "[^/]+" |
| 51 | if typ == regexpTypeQuery { |
| 52 | defaultPattern = ".*" |
| 53 | } else if typ == regexpTypeHost { |
| 54 | defaultPattern = "[^.]+" |
| 55 | } |
| 56 | // Only match strict slash if not matching |
| 57 | if typ != regexpTypePath { |
| 58 | options.strictSlash = false |
| 59 | } |
| 60 | // Set a flag for strictSlash. |
| 61 | endSlash := false |
| 62 | if options.strictSlash && strings.HasSuffix(tpl, "/") { |
| 63 | tpl = tpl[:len(tpl)-1] |
| 64 | endSlash = true |
| 65 | } |
| 66 | varsN := make([]string, len(idxs)/2) |
| 67 | varsR := make([]*regexp.Regexp, len(idxs)/2) |
| 68 | pattern := bytes.NewBufferString("") |
| 69 | pattern.WriteByte('^') |
| 70 | reverse := bytes.NewBufferString("") |
| 71 | var end int |
| 72 | var err error |
| 73 | for i := 0; i < len(idxs); i += 2 { |
| 74 | // Set all values we are interested in. |
| 75 | raw := tpl[end:idxs[i]] |
| 76 | end = idxs[i+1] |
| 77 | parts := strings.SplitN(tpl[idxs[i]+1:end-1], ":", 2) |
| 78 | name := parts[0] |
| 79 | patt := defaultPattern |
| 80 | if len(parts) == 2 { |
| 81 | patt = parts[1] |
| 82 | } |
| 83 | // Name or pattern can't be empty. |
| 84 | if name == "" || patt == "" { |
| 85 | return nil, fmt.Errorf("mux: missing name or pattern in %q", |
| 86 | tpl[idxs[i]:end]) |
| 87 | } |
| 88 | // Build the regexp pattern. |
| 89 | fmt.Fprintf(pattern, "%s(?P<%s>%s)", regexp.QuoteMeta(raw), varGroupName(i/2), patt) |
| 90 | |
| 91 | // Build the reverse template. |
| 92 | fmt.Fprintf(reverse, "%s%%s", raw) |
| 93 | |
| 94 | // Append variable name and compiled pattern. |
| 95 | varsN[i/2] = name |
| 96 | varsR[i/2], err = regexp.Compile(fmt.Sprintf("^%s$", patt)) |
| 97 | if err != nil { |
| 98 | return nil, err |