Add YAML configuration (#5)

README.md

@@ -25,10 +25,14 @@ type Info struct {
 
 ### Scraper
 
+Scraper may be instantiated in one of two ways:
+* from the code
+* from the YAML file
+
 In order to instantiate the scraper you need to provide scraper configuration which contains a slice of prefixes of packages that you want to reflect. Types that do not match any of the given prefixes will not be traversed. 
 ```go
 config := scraper.NewConfiguration(
-    "github.com/karhoo/svc-billing",
+    "github.com/krzysztofreczek/pkg",
 )
 s := scraper.NewScraper(config)
 ```
@@ -41,15 +45,37 @@ Each rule consists of:
 * Apply function - function that produces `model.Info` describing the component included in the scraped structure
 
 ```go
-r, _ := scraper.NewRule().
+r, err := scraper.NewRule().
     WithPkgRegexps("github.com/krzysztofreczek/pkg/foo/.*").
     WithNameRegexp("^(.*)Client$").
     WithApplyFunc(
         func() model.Info {
             return model.ComponentInfo("foo client", "client of a foo service", "TAG")
         }).
     Build()
-_ = s.RegisterRule(r)
+err = s.RegisterRule(r)
+```
+
+Alternatively, you can instantiate the scraper form YAML configuration file:
+```yaml
+// go-structurizr.yml
+configuration:
+  pkgs:
+    - "github.com/krzysztofreczek/pkg"
+
+rules:
+  - name_regexp: "^(.*)Client$"
+    pkg_regexps:
+      - "github.com/krzysztofreczek/pkg/foo/.*"
+    component:
+      description: "foo client"
+      technology: "client of a foo service"
+      tags:
+      - TAG
+```
+
+```go
+s, err := scraper.NewScraperFromConfigFile("./go-structurizr.yml")
 ```
 
 Eventually, having the scraper instantiated and configured you can use it to scrape any structure you want. Scraper returns a struct `model.Structure`.
@@ -59,6 +85,10 @@ structure := s.Scrap(app)
 
 ### View
 
+Similarly to the scraper, view may be instantiated in one of two ways:
+* from the code
+* from the YAML file
+
 In order to render scraped structure, you will need to instantiate and configure a view.
 View consists of:
 * title
@@ -73,6 +103,7 @@ v := view.NewView().Build()
 In case you need to customize it, use available builder methods:
 ```go
 v := view.NewView().
+    WithTitle("Title")
     WithComponentStyle(
         view.NewComponentStyle("TAG").
             WithBackgroundColor(color.White).
@@ -82,6 +113,23 @@ v := view.NewView().
     Build()
 ```
 
+Alternatively, you can instantiate the view form YAML configuration file:
+```yaml
+// go-structurizr.yml
+view:
+  title: "Title"
+  line_color: 000000ff
+  styles:
+    - id: TAG
+      background_color: ffffffff
+      font_color: 000000ff
+      border_color: 000000ff
+```
+
+```go
+v, err := view.NewViewFromConfigFile("./go-structurizr.yml")
+```
+
 As the view is initialized, you can now render the structure into planUML diagram.
 ```go
 outFile, _ := os.Create("c4.plantuml")

go.mod

@@ -2,4 +2,7 @@ module github.com/krzysztofreczek/go-structurizr
 
 go 1.15
 
-require github.com/pkg/errors v0.9.1
+require (
+	github.com/pkg/errors v0.9.1
+	gopkg.in/yaml.v2 v2.3.0
+)

go.sum

@@ -1,2 +1,5 @@
 github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.3.0 h1:clyUAQHOM3G0M3f5vQj7LuJrETvjVot3Z5el9nffUtU=
+gopkg.in/yaml.v2 v2.3.0/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

pkg/scraper/config.go

@@ -9,4 +9,3 @@ func NewConfiguration(packages ...string) Configuration {
 		packages: packages,
 	}
 }
-

pkg/scraper/scraper.go

@@ -1,14 +1,15 @@
 package scraper
 
 import (
-	"errors"
 	"fmt"
 	"hash/fnv"
 	"reflect"
 	"strings"
 	"unsafe"
 
 	"github.com/krzysztofreczek/go-structurizr/pkg/model"
+	"github.com/krzysztofreczek/go-structurizr/pkg/yaml"
+	"github.com/pkg/errors"
 )
 
 type Scraper struct {
@@ -25,6 +26,27 @@ func NewScraper(config Configuration) *Scraper {
 	}
 }
 
+func NewScraperFromConfigFile(fileName string) (*Scraper, error) {
+	configuration, err := yaml.LoadFromFile(fileName)
+	if err != nil {
+		return nil, errors.Wrapf(err,
+			"could not load configuration from file `%s`", fileName)
+	}
+
+	config := toScraperConfig(configuration)
+	rules, err := toScraperRules(configuration)
+	if err != nil {
+		return nil, errors.Wrapf(err,
+			"could not load scraper rules from from configuration file `%s`", fileName)
+	}
+
+	return &Scraper{
+		config:    config,
+		rules:     rules,
+		structure: model.NewStructure(),
+	}, nil
+}
+
 func (s *Scraper) RegisterRule(r Rule) error {
 	if r == nil {
 		return errors.New("rule must not be nil")
@@ -67,7 +89,6 @@ func (s *Scraper) scrap(
 		for i := 0; i < v.Len(); i++ {
 			s.scrap(v.Index(i), parentID, level)
 		}
-		return
 	}
 
 	v = normalize(v)

pkg/scraper/yaml.go

@@ -0,0 +1,40 @@
+package scraper
+
+import (
+	"github.com/krzysztofreczek/go-structurizr/pkg/model"
+	"github.com/krzysztofreczek/go-structurizr/pkg/yaml"
+)
+
+func toScraperConfig(c yaml.Config) Configuration {
+	return NewConfiguration(c.Configuration.Packages...)
+}
+
+func toScraperRules(c yaml.Config) ([]Rule, error) {
+	rules := make([]Rule, len(c.Rules))
+	for i, r := range c.Rules {
+		r := r
+		rule, err := NewRule().
+			WithNameRegexp(r.NameRegexp).
+			WithPkgRegexps(r.PackageRegexps...).
+			WithApplyFunc(
+				func() model.Info {
+					info := make([]string, len(r.Component.Tags)+2)
+					info[0] = r.Component.Description
+					info[1] = r.Component.Technology
+
+					idx := 2
+					for _, t := range r.Component.Tags {
+						info[idx] = t
+						idx++
+					}
+
+					return model.ComponentInfo(info...)
+				},
+			).Build()
+		if err != nil {
+			return nil, err
+		}
+		rules[i] = rule
+	}
+	return rules, nil
+}

pkg/view/snippets.go

@@ -82,9 +82,9 @@ func buildSkinParamRectangle(
 ) string {
 	s := snippetSkinParamRectangle
 	s = strings.Replace(s, paramRectangleName, name, -1)
-	s = strings.Replace(s, paramBackgroundColor, hex(backgroundColor), -1)
-	s = strings.Replace(s, paramFontColor, hex(fontColor), -1)
-	s = strings.Replace(s, paramBorderColor, hex(borderColor), -1)
+	s = strings.Replace(s, paramBackgroundColor, toHex(backgroundColor), -1)
+	s = strings.Replace(s, paramFontColor, toHex(fontColor), -1)
+	s = strings.Replace(s, paramBorderColor, toHex(borderColor), -1)
 	return s
 }
 
@@ -118,11 +118,11 @@ func buildComponentConnection(
 	s := snippetComponentConnection
 	s = strings.Replace(s, paramComponentIDFrom, fromID, -1)
 	s = strings.Replace(s, paramComponentIDTo, toID, -1)
-	s = strings.Replace(s, paramLineColor, hex(lineColor), -1)
+	s = strings.Replace(s, paramLineColor, toHex(lineColor), -1)
 	return s
 }
 
-func hex(c color.Color) string {
+func toHex(c color.Color) string {
 	rgba := color.RGBAModel.Convert(c).(color.RGBA)
 	return fmt.Sprintf("#%.2x%.2x%.2x", rgba.R, rgba.G, rgba.B)
 }

pkg/view/view.go

@@ -1,6 +1,11 @@
 package view
 
-import "image/color"
+import (
+	"image/color"
+
+	"github.com/krzysztofreczek/go-structurizr/pkg/yaml"
+	"github.com/pkg/errors"
+)
 
 type View struct {
 	title           string
@@ -34,6 +39,22 @@ func NewView() *Builder {
 	}
 }
 
+func NewViewFromConfigFile(fileName string) (View, error) {
+	configuration, err := yaml.LoadFromFile(fileName)
+	if err != nil {
+		return View{}, errors.Wrapf(err,
+			"could not load configuration from file `%s`", fileName)
+	}
+
+	v, err := toView(configuration)
+	if err != nil {
+		return View{}, errors.Wrapf(err,
+			"could not load view from file `%s`", fileName)
+	}
+
+	return v, nil
+}
+
 func (b *Builder) WithTitle(t string) *Builder {
 	b.title = t
 	return b

pkg/view/yaml.go

@@ -0,0 +1,62 @@
+package view
+
+import (
+	"encoding/hex"
+	"image/color"
+	"log"
+
+	"github.com/krzysztofreczek/go-structurizr/pkg/yaml"
+)
+
+func toView(c yaml.Config) (View, error) {
+	v := NewView().WithTitle(c.View.Title)
+
+	if c.View.LineColor != "" {
+		col, err := decodeHexColor(c.View.LineColor)
+		if err != nil {
+			return View{}, err
+		}
+		v.WithLineColor(col)
+	}
+
+	for _, s := range c.View.Styles {
+		style := NewComponentStyle(s.ID)
+
+		if s.BackgroundColor != "" {
+			col, err := decodeHexColor(s.BackgroundColor)
+			if err != nil {
+				return View{}, err
+			}
+			style.WithBackgroundColor(col)
+		}
+
+		if s.FontColor != "" {
+			col, err := decodeHexColor(s.FontColor)
+			if err != nil {
+				return View{}, err
+			}
+			style.WithFontColor(col)
+		}
+
+		if s.BorderColor != "" {
+			col, err := decodeHexColor(s.BorderColor)
+			if err != nil {
+				return View{}, err
+			}
+			style.WithBorderColor(col)
+		}
+
+		v.WithComponentStyle(style.Build())
+	}
+
+	return v.Build(), nil
+}
+
+func decodeHexColor(s string) (color.Color, error) {
+	b, err := hex.DecodeString(s)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	return color.RGBA{R: b[0], G: b[1], B: b[2], A: 255}, nil
+}