Squashed 'v2/' content from commit 72ef153

git-subtree-dir: v2
git-subtree-split: 72ef15359e36e42b18d9407f74c762f83eb9a099

internal/binding/boundMethod.go

@@ -0,0 +1,138 @@
+package binding
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+)
+
+// BoundMethod defines all the data related to a Go method that is
+// bound to the Wails application
+type BoundMethod struct {
+	Name     string        `json:"name"`
+	Inputs   []*Parameter  `json:"inputs,omitempty"`
+	Outputs  []*Parameter  `json:"outputs,omitempty"`
+	Comments string        `json:"comments,omitempty"`
+	Method   reflect.Value `json:"-"`
+}
+
+// IsWailsInit returns true if the method name is "WailsInit"
+func (b *BoundMethod) IsWailsInit() bool {
+	return strings.HasSuffix(b.Name, "WailsInit")
+}
+
+// IsWailsShutdown returns true if the method name is "WailsShutdown"
+func (b *BoundMethod) IsWailsShutdown() bool {
+	return strings.HasSuffix(b.Name, "WailsShutdown")
+}
+
+// VerifyWailsInit checks if the WailsInit signature is correct
+func (b *BoundMethod) VerifyWailsInit() error {
+	// Must only have 1 input
+	if b.InputCount() != 1 {
+		return fmt.Errorf("invalid method signature for %s: expected `WailsInit(*wails.Runtime) error`", b.Name)
+	}
+
+	// Check input type
+	if !b.Inputs[0].IsType("*goruntime.Runtime") {
+		return fmt.Errorf("invalid method signature for %s: expected `WailsInit(*wails.Runtime) error`", b.Name)
+	}
+
+	// Must only have 1 output
+	if b.OutputCount() != 1 {
+		return fmt.Errorf("invalid method signature for %s: expected `WailsInit(*wails.Runtime) error`", b.Name)
+	}
+
+	// Check output type
+	if !b.Outputs[0].IsError() {
+		return fmt.Errorf("invalid method signature for %s: expected `WailsInit(*wails.Runtime) error`", b.Name)
+	}
+
+	// Input must be of type Runtime
+	return nil
+}
+
+// VerifyWailsShutdown checks if the WailsShutdown signature is correct
+func (b *BoundMethod) VerifyWailsShutdown() error {
+	// Must have no inputs
+	if b.InputCount() != 0 {
+		return fmt.Errorf("invalid method signature for WailsShutdown: expected `WailsShutdown()`")
+	}
+
+	// Must have no outputs
+	if b.OutputCount() != 0 {
+		return fmt.Errorf("invalid method signature for WailsShutdown: expected `WailsShutdown()`")
+	}
+
+	// Input must be of type Runtime
+	return nil
+}
+
+// InputCount returns the number of inputs this bound method has
+func (b *BoundMethod) InputCount() int {
+	return len(b.Inputs)
+}
+
+// OutputCount returns the number of outputs this bound method has
+func (b *BoundMethod) OutputCount() int {
+	return len(b.Outputs)
+}
+
+// Call will attempt to call this bound method with the given args
+func (b *BoundMethod) Call(args []interface{}) (interface{}, error) {
+	// Check inputs
+	expectedInputLength := len(b.Inputs)
+	actualInputLength := len(args)
+	if expectedInputLength != actualInputLength {
+		return nil, fmt.Errorf("%s takes %d inputs. Received %d", b.Name, expectedInputLength, actualInputLength)
+	}
+
+	/** Convert inputs to reflect values **/
+
+	// Create slice for the input arguments to the method call
+	callArgs := make([]reflect.Value, expectedInputLength)
+
+	// Iterate over given arguments
+	for index, arg := range args {
+
+		// Attempt to convert the argument to the type expected by the method
+		value, err := convertArgToValue(arg, b.Inputs[index])
+
+		// If it fails, return a suitable error
+		if err != nil {
+			return nil, fmt.Errorf("%s (parameter %d): %s", b.Name, index+1, err.Error())
+		}
+
+		// Save the converted argument
+		callArgs[index] = value
+	}
+
+	// Do the call
+	callResults := b.Method.Call(callArgs)
+
+	//** Check results **//
+	var returnValue interface{}
+	var err error
+
+	switch b.OutputCount() {
+	case 1:
+		// Loop over results and determine if the result
+		// is an error or not
+		for _, result := range callResults {
+			interfac := result.Interface()
+			temp, ok := interfac.(error)
+			if ok {
+				err = temp
+			} else {
+				returnValue = interfac
+			}
+		}
+	case 2:
+		returnValue = callResults[0].Interface()
+		if temp, ok := callResults[1].Interface().(error); ok {
+			err = temp
+		}
+	}
+
+	return returnValue, err
+}