Next (#214)

* Renamed DOCUMENT to PAGE

* Added PageLoadParams

* Added PageLoadParams

* Renamed LoadPageParams -> PageLoadParams

* Added support for context.Done() (#201)

* Bug/#189 operators precedence (#202)

* Fixed math operators precedence

* Fixed logical operators precedence

* Fixed array operator

* Added support for parentheses to enforce a different operator evaluation order

* Feature/#200 drivers (#209)

* Added new interfaces

* Renamed dynamic to cdp driver

* Renamed drivers

* Added ELEMENT_EXISTS function (#210)

* Renamed back PAGE to DOCUMENT (#211)

* Added Getter and Setter interfaces

pkg/stdlib/html/screenshot.go

@@ -0,0 +1,163 @@
+package html
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/MontFerret/ferret/pkg/runtime/core"
+	"github.com/MontFerret/ferret/pkg/runtime/values"
+)
+
+// Screenshot takes a screenshot of the current page.
+// @param source (Document) - Document.
+// @param params (Object) - Optional, An object containing the following properties :
+// 		x (Float|Int) - Optional, X position of the viewport.
+// 		x (Float|Int) - Optional,Y position of the viewport.
+// 		width (Float|Int) - Optional, Width of the viewport.
+// 		height (Float|Int) - Optional, Height of the viewport.
+// 		format (String) - Optional, Either "jpeg" or "png".
+// 		quality (Int) - Optional, Quality, in [0, 100], only for jpeg format.
+// @returns data (Binary) - Returns a base64 encoded string in binary format.
+func Screenshot(ctx context.Context, args ...core.Value) (core.Value, error) {
+	err := core.ValidateArgs(args, 1, 2)
+
+	if err != nil {
+		return values.None, err
+	}
+
+	arg1 := args[0]
+
+	err = core.ValidateType(arg1, core.HTMLDocumentType, core.StringType)
+
+	if err != nil {
+		return values.None, err
+	}
+
+	val, err := ValidateDocument(ctx, arg1)
+
+	if err != nil {
+		return values.None, err
+	}
+
+	doc := val.(values.DHTMLDocument)
+
+	defer doc.Close()
+
+	screenshotParams := values.HTMLScreenshotParams{
+		X:       0,
+		Y:       0,
+		Width:   -1,
+		Height:  -1,
+		Format:  values.HTMLScreenshotFormatJPEG,
+		Quality: 100,
+	}
+
+	if len(args) == 2 {
+		arg2 := args[1]
+		err = core.ValidateType(arg2, core.ObjectType)
+
+		if err != nil {
+			return values.None, err
+		}
+
+		params, ok := arg2.(*values.Object)
+
+		if !ok {
+			return values.None, core.Error(core.ErrInvalidType, "expected object")
+		}
+
+		format, found := params.Get("format")
+
+		if found {
+			err = core.ValidateType(format, core.StringType)
+
+			if err != nil {
+				return values.None, err
+			}
+
+			if !values.IsHTMLScreenshotFormatValid(format.String()) {
+				return values.None, core.Error(
+					core.ErrInvalidArgument,
+					fmt.Sprintf("format is not valid, expected jpeg or png, but got %s", format.String()))
+			}
+
+			screenshotParams.Format = values.HTMLScreenshotFormat(format.String())
+		}
+
+		x, found := params.Get("x")
+
+		if found {
+			err = core.ValidateType(x, core.FloatType, core.IntType)
+
+			if err != nil {
+				return values.None, err
+			}
+
+			if x.Type() == core.IntType {
+				screenshotParams.X = values.Float(x.(values.Int))
+			}
+		}
+
+		y, found := params.Get("y")
+
+		if found {
+			err = core.ValidateType(y, core.FloatType, core.IntType)
+
+			if err != nil {
+				return values.None, err
+			}
+
+			if y.Type() == core.IntType {
+				screenshotParams.Y = values.Float(y.(values.Int))
+			}
+		}
+
+		width, found := params.Get("width")
+
+		if found {
+			err = core.ValidateType(width, core.FloatType, core.IntType)
+
+			if err != nil {
+				return values.None, err
+			}
+
+			if width.Type() == core.IntType {
+				screenshotParams.Width = values.Float(width.(values.Int))
+			}
+		}
+
+		height, found := params.Get("height")
+
+		if found {
+			err = core.ValidateType(height, core.FloatType, core.IntType)
+
+			if err != nil {
+				return values.None, err
+			}
+
+			if height.Type() == core.IntType {
+				screenshotParams.Height = values.Float(height.(values.Int))
+			}
+		}
+
+		quality, found := params.Get("quality")
+
+		if found {
+			err = core.ValidateType(quality, core.IntType)
+
+			if err != nil {
+				return values.None, err
+			}
+
+			screenshotParams.Quality = quality.(values.Int)
+		}
+	}
+
+	scr, err := doc.CaptureScreenshot(screenshotParams)
+
+	if err != nil {
+		return values.None, err
+	}
+
+	return scr, nil
+}