Initial rewrite of revel/cmd to provide vendor support and enhanced CLI options

utils/error.go

@@ -0,0 +1,81 @@
+package utils
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+// The error is a wrapper for the
+type Error struct {
+	SourceType               string   // The type of source that failed to build.
+	Title, Path, Description string   // Description of the error, as presented to the user.
+	Line, Column             int      // Where the error was encountered.
+	SourceLines              []string // The entire source file, split into lines.
+	Stack                    string   // The raw stack trace string from debug.Stack().
+	MetaError                string   // Error that occurred producing the error page.
+	Link                     string   // A configurable link to wrap the error source in
+}
+
+// Creates a link based on the configuration setting "errors.link"
+func (e *Error) SetLink(errorLink string) {
+	errorLink = strings.Replace(errorLink, "{{Path}}", e.Path, -1)
+	errorLink = strings.Replace(errorLink, "{{Line}}", strconv.Itoa(e.Line), -1)
+
+	e.Link = "<a href=" + errorLink + ">" + e.Path + ":" + strconv.Itoa(e.Line) + "</a>"
+}
+
+// Error method constructs a plaintext version of the error, taking
+// account that fields are optionally set. Returns e.g. Compilation Error
+// (in views/header.html:51): expected right delim in end; got "}"
+func (e *Error) Error() string {
+	if e == nil {
+		panic("opps")
+	}
+	loc := ""
+	if e.Path != "" {
+		line := ""
+		if e.Line != 0 {
+			line = fmt.Sprintf(":%d", e.Line)
+		}
+		loc = fmt.Sprintf("(in %s%s)", e.Path, line)
+	}
+	header := loc
+	if e.Title != "" {
+		if loc != "" {
+			header = fmt.Sprintf("%s %s: ", e.Title, loc)
+		} else {
+			header = fmt.Sprintf("%s: ", e.Title)
+		}
+	}
+	return fmt.Sprintf("%s%s", header, e.Description)
+}
+// ContextSource method returns a snippet of the source around
+// where the error occurred.
+func (e *Error) ContextSource() []SourceLine {
+	if e.SourceLines == nil {
+		return nil
+	}
+	start := (e.Line - 1) - 5
+	if start < 0 {
+		start = 0
+	}
+	end := (e.Line - 1) + 5
+	if end > len(e.SourceLines) {
+		end = len(e.SourceLines)
+	}
+
+	lines := make([]SourceLine, end-start)
+	for i, src := range e.SourceLines[start:end] {
+		fileLine := start + i + 1
+		lines[i] = SourceLine{src, fileLine, fileLine == e.Line}
+	}
+	return lines
+}
+
+// SourceLine structure to hold the per-source-line details.
+type SourceLine struct {
+	Source  string
+	Line    int
+	IsError bool
+}