--- /dev/null
+// Copyright (c) 2012-2016 The Revel Framework Authors, All rights reserved.
+// Revel Framework source code and usage is governed by a MIT style
+// license that can be found in the LICENSE file.
+
+package revel
+
+import (
+ "fmt"
+ "path/filepath"
+ "runtime/debug"
+ "strconv"
+ "strings"
+)
+
+// Error description, used as an argument to the error template.
+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
+}
+
+// SourceLine structure to hold the per-source-line details.
+type SourceLine struct {
+ Source string
+ Line int
+ IsError bool
+}
+
+// NewErrorFromPanic method finds the deepest stack from in user code and
+// provide a code listing of that, on the line that eventually triggered
+// the panic. Returns nil if no relevant stack frame can be found.
+func NewErrorFromPanic(err interface{}) *Error {
+
+ // Parse the filename and line from the originating line of app code.
+ // /Users/robfig/code/gocode/src/revel/examples/booking/app/controllers/hotels.go:191 (0x44735)
+ stack := string(debug.Stack())
+ frame, basePath := findRelevantStackFrame(stack)
+ if frame == -1 {
+ return nil
+ }
+
+ stack = stack[frame:]
+ stackElement := stack[:strings.Index(stack, "\n")]
+ colonIndex := strings.LastIndex(stackElement, ":")
+ filename := stackElement[:colonIndex]
+ var line int
+ fmt.Sscan(stackElement[colonIndex+1:], &line)
+
+ // Show an error page.
+ description := "Unspecified error"
+ if err != nil {
+ description = fmt.Sprint(err)
+ }
+ lines, readErr := ReadLines(filename)
+ if readErr != nil {
+ utilLog.Error("Unable to read file", "file", filename, "error", readErr)
+ }
+ return &Error{
+ Title: "Runtime Panic",
+ Path: filename[len(basePath):],
+ Line: line,
+ Description: description,
+ SourceLines: lines,
+ Stack: stack,
+ }
+}
+
+// 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 {
+ 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 Stack: %s", header, e.Description, e.Stack)
+}
+
+// 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
+}
+
+// SetLink method prepares a link and assign to Error.Link attribute
+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>"
+}
+
+// Return the character index of the first relevant stack frame, or -1 if none were found.
+// Additionally it returns the base path of the tree in which the identified code resides.
+func findRelevantStackFrame(stack string) (int, string) {
+ // Find first item in SourcePath that isn't in RevelPath.
+ // If first item is in RevelPath, keep track of position, trim and check again.
+ partialStack := stack
+ sourcePath := filepath.ToSlash(SourcePath)
+ revelPath := filepath.ToSlash(RevelPath)
+ sumFrame := 0
+ for {
+ frame := strings.Index(partialStack, sourcePath)
+ revelFrame := strings.Index(partialStack, revelPath)
+
+ if frame == -1 {
+ break
+ } else if frame != revelFrame {
+ return sumFrame + frame, SourcePath
+ } else {
+ // Need to at least trim off the first character so this frame isn't caught again.
+ partialStack = partialStack[frame+1:]
+ sumFrame += frame + 1
+ }
+ }
+ for _, module := range Modules {
+ if frame := strings.Index(stack, filepath.ToSlash(module.Path)); frame != -1 {
+ return frame, module.Path
+ }
+ }
+ return -1, ""
+}
Code Review / iec.git / blobdiff