#104 Added NAVIGATE_FORWARD function (#108)

examples/navigate_forward.fql

@@ -0,0 +1,9 @@
+LET origin = "https://github.com/"
+LET target = "https://github.com/features"
+LET doc = DOCUMENT(origin, true)
+
+NAVIGATE(doc, target)
+NAVIGATE_BACK(doc)
+NAVIGATE_FORWARD(doc)
+
+RETURN doc.url == target

examples/navigate_forward_2.fql

@@ -0,0 +1,9 @@
+LET doc = DOCUMENT("https://github.com/", true)
+
+NAVIGATE(doc, "https://github.com/features")
+NAVIGATE(doc, "https://github.com/business")
+NAVIGATE(doc, "https://github.com/marketplace")
+NAVIGATE_BACK(doc, 3)
+NAVIGATE_FORWARD(doc, 2)
+
+RETURN doc.url == "https://github.com/business"

pkg/html/dynamic/document.go

@@ -643,6 +643,49 @@ func (doc *HTMLDocument) NavigateBack(skip values.Int, timeout values.Int) (valu
 	return values.True, nil
 }
 
+func (doc *HTMLDocument) NavigateForward(skip values.Int, timeout values.Int) (values.Boolean, error) {
+	ctx := context.Background()
+	history, err := doc.client.Page.GetNavigationHistory(ctx)
+
+	if err != nil {
+		return values.False, err
+	}
+
+	length := len(history.Entries)
+	lastIndex := length - 1
+
+	// nowhere to go forward
+	if history.CurrentIndex == lastIndex {
+		return values.False, nil
+	}
+
+	if skip < 1 {
+		skip = 1
+	}
+
+	to := int(skip) + history.CurrentIndex
+
+	if to > lastIndex {
+		// TODO: Return error?
+		return values.False, nil
+	}
+
+	next := history.Entries[to]
+	err = doc.client.Page.NavigateToHistoryEntry(ctx, page.NewNavigateToHistoryEntryArgs(next.ID))
+
+	if err != nil {
+		return values.False, err
+	}
+
+	err = doc.WaitForNavigation(timeout)
+
+	if err != nil {
+		return values.False, err
+	}
+
+	return values.True, nil
+}
+
 func (doc *HTMLDocument) CaptureScreenshot(params *ScreenshotArgs) (core.Value, error) {
 	ctx := context.Background()
 	metrics, err := doc.client.Page.GetLayoutMetrics(ctx)

pkg/stdlib/html/lib.go

@@ -13,23 +13,24 @@ var (
 
 func NewLib() map[string]core.Function {
 	return map[string]core.Function{
-		"DOCUMENT":        Document,
-		"DOCUMENT_PARSE":  DocumentParse,
-		"ELEMENT":         Element,
-		"ELEMENTS":        Elements,
-		"WAIT_ELEMENT":    WaitElement,
-		"WAIT_NAVIGATION": WaitNavigation,
-		"WAIT_CLASS":      WaitClass,
-		"WAIT_CLASS_ALL":  WaitClassAll,
-		"CLICK":           Click,
-		"CLICK_ALL":       ClickAll,
-		"NAVIGATE":        Navigate,
-		"NAVIGATE_BACK":   NavigateBack,
-		"INPUT":           Input,
-		"INNER_HTML":      InnerHTML,
-		"INNER_HTML_ALL":  InnerHTMLAll,
-		"INNER_TEXT":      InnerText,
-		"INNER_TEXT_ALL":  InnerTextAll,
-		"SCREENSHOT":      Screenshot,
+		"DOCUMENT":         Document,
+		"DOCUMENT_PARSE":   DocumentParse,
+		"ELEMENT":          Element,
+		"ELEMENTS":         Elements,
+		"WAIT_ELEMENT":     WaitElement,
+		"WAIT_NAVIGATION":  WaitNavigation,
+		"WAIT_CLASS":       WaitClass,
+		"WAIT_CLASS_ALL":   WaitClassAll,
+		"CLICK":            Click,
+		"CLICK_ALL":        ClickAll,
+		"NAVIGATE":         Navigate,
+		"NAVIGATE_BACK":    NavigateBack,
+		"NAVIGATE_FORWARD": NavigateForward,
+		"INPUT":            Input,
+		"INNER_HTML":       InnerHTML,
+		"INNER_HTML_ALL":   InnerHTMLAll,
+		"INNER_TEXT":       InnerText,
+		"INNER_TEXT_ALL":   InnerTextAll,
+		"SCREENSHOT":       Screenshot,
 	}
 }

pkg/stdlib/html/navigate_forward.go

@@ -0,0 +1,62 @@
+package html
+
+import (
+	"context"
+	"github.com/MontFerret/ferret/pkg/html/dynamic"
+	"github.com/MontFerret/ferret/pkg/runtime/core"
+	"github.com/MontFerret/ferret/pkg/runtime/values"
+)
+
+/*
+ * Navigates a document forward within its navigation history.
+ * The operation blocks the execution until the page gets loaded.
+ * If the history is empty, the function returns FALSE.
+ * @param doc (Document) - Target document.
+ * @param entry (Int, optional) - Optional value indicating how many pages to skip. Default 1.
+ * @param timeout (Int, optional) - Optional timeout. Default is 5000.
+ * @returns (Boolean) - Returns TRUE if history exists and the operation succeeded, otherwise FALSE.
+ */
+func NavigateForward(_ context.Context, args ...core.Value) (core.Value, error) {
+	err := core.ValidateArgs(args, 1, 3)
+
+	if err != nil {
+		return values.False, err
+	}
+
+	err = core.ValidateType(args[0], core.HTMLDocumentType)
+
+	if err != nil {
+		return values.None, err
+	}
+
+	doc, ok := args[0].(*dynamic.HTMLDocument)
+
+	if !ok {
+		return values.False, core.Errors(core.ErrInvalidType, ErrNotDynamic)
+	}
+
+	skip := values.NewInt(1)
+	timeout := values.NewInt(defaultTimeout)
+
+	if len(args) > 1 {
+		err = core.ValidateType(args[1], core.IntType)
+
+		if err != nil {
+			return values.None, err
+		}
+
+		skip = args[1].(values.Int)
+	}
+
+	if len(args) > 2 {
+		err = core.ValidateType(args[2], core.IntType)
+
+		if err != nil {
+			return values.None, err
+		}
+
+		timeout = args[2].(values.Int)
+	}
+
+	return doc.NavigateForward(skip, timeout)
+}