WTF-482 Sanity-check position configuration data for modules

If a module is missing any of the positional data it now informs the
user and exits gracefully with an error.

cfg/common_settings.go

@@ -30,12 +30,12 @@ type Module struct {
 	Type string
 }
 
-type Position struct {
+// type Position struct {
-	Height int
+// 	Height int
-	Left   int
+// 	Left   int
-	Top    int
+// 	Top    int
-	Width  int
+// 	Width  int
-}
+// }
 
 type Sigils struct {
 	Checkbox struct {
@@ -64,7 +64,7 @@ type Common struct {
 
 func NewCommonSettingsFromModule(name, defaultTitle string, moduleConfig *config.Config, globalSettings *config.Config) *Common {
 	colorsConfig, _ := globalSettings.Get("wtf.colors")
-	positionPath := "position"
+	// positionPath := "position"
 	sigilsPath := "wtf.sigils"
 
 	common := Common{
@@ -86,12 +86,7 @@ func NewCommonSettingsFromModule(name, defaultTitle string, moduleConfig *config
 			Type: moduleConfig.UString("type", name),
 		},
 
-		Position: Position{
+		Position: NewPositionFromYAML(name, moduleConfig),
-			Height: moduleConfig.UInt(positionPath + ".height"),
-			Left:   moduleConfig.UInt(positionPath + ".left"),
-			Top:    moduleConfig.UInt(positionPath + ".top"),
-			Width:  moduleConfig.UInt(positionPath + ".width"),
-		},
 
 		Enabled:         moduleConfig.UBool("enabled", false),
 		RefreshInterval: moduleConfig.UInt("refreshInterval", 300),

cfg/config_files.go

@@ -132,6 +132,7 @@ func LoadConfigFile(filePath string) *config.Config {
 		fmt.Println("    2. Your \033[0;33mconfig.yml\033[0m file has a syntax error. Try running it through http://www.yamllint.com to check for errors.")
 		fmt.Println()
 		fmt.Printf("Error: \033[0;31m%s\033[0m\n\n", err.Error())
+
 		os.Exit(1)
 	}
 

cfg/position.go

@@ -0,0 +1,73 @@
+package cfg
+
+import (
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/olebedev/config"
+)
+
+const (
+	positionPath = "position"
+)
+
+// Position represents the onscreen location of a widget
+type Position struct {
+	Height int
+	Left   int
+	Top    int
+	Width  int
+}
+
+// NewPositionFromYAML creates and returns a new instance of Position
+func NewPositionFromYAML(name string, moduleConfig *config.Config) Position {
+	errs := make(map[string]error)
+
+	// Parse the positional data from the config data
+	top, err := moduleConfig.Int(positionPath + ".top")
+	errs["top"] = err
+
+	left, err := moduleConfig.Int(positionPath + ".left")
+	errs["left"] = err
+
+	width, err := moduleConfig.Int(positionPath + ".width")
+	errs["width"] = err
+
+	height, err := moduleConfig.Int(positionPath + ".height")
+	errs["height"] = err
+
+	validatePositions(name, errs)
+
+	pos := Position{
+		Top:    top,
+		Left:   left,
+		Width:  width,
+		Height: height,
+	}
+
+	return pos
+}
+
+/* -------------------- Unexported Functions -------------------- */
+
+// If any of the position values have an error then we inform the user and exit the app
+func validatePositions(name string, errs map[string]error) {
+	var errStr string
+
+	for pos, err := range errs {
+		if err != nil {
+			errStr += fmt.Sprintf("  - Invalid value for %s\n", pos)
+		}
+	}
+
+	if errStr != "" {
+		fmt.Println()
+		fmt.Printf("\033[0;31mErrors in %s configuration\033[0m\n", strings.Title(name))
+		fmt.Println(errStr)
+		fmt.Println("Please check your config.yml file.")
+		fmt.Println()
+
+		os.Exit(1)
+	}
+}