Squashed 'v2/' content from commit 72ef153

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

internal/binding/binding.go

@@ -0,0 +1,70 @@
+package binding
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/wailsapp/wails/v2/internal/logger"
+)
+
+type Bindings struct {
+	db     *DB
+	logger logger.CustomLogger
+}
+
+// NewBindings returns a new Bindings object
+func NewBindings(logger *logger.Logger) *Bindings {
+	return &Bindings{
+		db:     newDB(),
+		logger: logger.CustomLogger("Bindings"),
+	}
+}
+
+// Add the given struct methods to the Bindings
+func (b *Bindings) Add(structPtr interface{}) error {
+
+	methods, err := getMethods(structPtr)
+	if err != nil {
+		return fmt.Errorf("cannout bind value to app: %s", err.Error())
+	}
+
+	for _, method := range methods {
+		splitName := strings.Split(method.Name, ".")
+		packageName := splitName[0]
+		structName := splitName[1]
+		methodName := splitName[2]
+
+		// Is this WailsInit?
+		if method.IsWailsInit() {
+			err := b.db.AddWailsInit(method)
+			if err != nil {
+				return err
+			}
+			b.logger.Trace("Registered WailsInit method: %s", method.Name)
+			continue
+		}
+
+		// Is this WailsShutdown?
+		if method.IsWailsShutdown() {
+			err := b.db.AddWailsShutdown(method)
+			if err != nil {
+				return err
+			}
+			b.logger.Trace("Registered WailsShutdown method: %s", method.Name)
+			continue
+		}
+
+		// Add it as a regular method
+		b.db.AddMethod(packageName, structName, methodName, method)
+
+	}
+	return nil
+}
+
+func (b *Bindings) DB() *DB {
+	return b.db
+}
+
+func (b *Bindings) ToJSON() (string, error) {
+	return b.db.ToJSON()
+}

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
+}

internal/binding/db.go

@@ -0,0 +1,150 @@
+package binding
+
+import (
+	"encoding/json"
+	"sync"
+	"unsafe"
+)
+
+// DB is our database of method bindings
+type DB struct {
+	//  map[packagename] -> map[structname] -> map[methodname]*method
+	store map[string]map[string]map[string]*BoundMethod
+
+	// This uses fully qualified method names as a shortcut for store traversal.
+	// It used for performance gains at runtime
+	methodMap map[string]*BoundMethod
+
+	// These are slices of methods registered using WailsInit and WailsShutdown
+	wailsInitMethods     []*BoundMethod
+	wailsShutdownMethods []*BoundMethod
+
+	// Lock to ensure sync access to the data
+	lock sync.RWMutex
+}
+
+func newDB() *DB {
+	return &DB{
+		store:     make(map[string]map[string]map[string]*BoundMethod),
+		methodMap: make(map[string]*BoundMethod),
+	}
+}
+
+// GetMethodFromStore returns the method for the given package/struct/method names
+// nil is returned if any one of those does not exist
+func (d *DB) GetMethodFromStore(packageName string, structName string, methodName string) *BoundMethod {
+
+	// Lock the db whilst processing and unlock on return
+	d.lock.RLock()
+	defer d.lock.RUnlock()
+
+	structMap, exists := d.store[packageName]
+	if !exists {
+		return nil
+	}
+	methodMap, exists := structMap[structName]
+	if !exists {
+		return nil
+	}
+	return methodMap[methodName]
+}
+
+// GetMethod returns the method for the given qualified method name
+// qualifiedMethodName is "packagename.structname.methodname"
+func (d *DB) GetMethod(qualifiedMethodName string) *BoundMethod {
+
+	// Lock the db whilst processing and unlock on return
+	d.lock.RLock()
+	defer d.lock.RUnlock()
+
+	return d.methodMap[qualifiedMethodName]
+}
+
+// AddMethod adds the given method definition to the db using the given qualified path: packageName.structName.methodName
+func (d *DB) AddMethod(packageName string, structName string, methodName string, methodDefinition *BoundMethod) {
+
+	// TODO: Validate inputs?
+
+	// Lock the db whilst processing and unlock on return
+	d.lock.Lock()
+	defer d.lock.Unlock()
+
+	// Get the map associated with the package name
+	structMap, exists := d.store[packageName]
+	if !exists {
+		// Create a new map for this packagename
+		d.store[packageName] = make(map[string]map[string]*BoundMethod)
+		structMap = d.store[packageName]
+	}
+
+	// Get the map associated with the struct name
+	methodMap, exists := structMap[structName]
+	if !exists {
+		// Create a new map for this packagename
+		structMap[structName] = make(map[string]*BoundMethod)
+		methodMap = structMap[structName]
+	}
+
+	// Store the method definition
+	methodMap[methodName] = methodDefinition
+
+	// Store in the methodMap
+	key := packageName + "." + structName + "." + methodName
+	d.methodMap[key] = methodDefinition
+
+}
+
+// AddWailsInit checks the given method is a WailsInit method and if it
+// is, adds it to the list of WailsInit methods
+func (d *DB) AddWailsInit(method *BoundMethod) error {
+	err := method.VerifyWailsInit()
+	if err != nil {
+		return err
+	}
+
+	// Lock the db whilst processing and unlock on return
+	d.lock.Lock()
+	defer d.lock.Unlock()
+
+	d.wailsInitMethods = append(d.wailsInitMethods, method)
+	return nil
+}
+
+// AddWailsShutdown checks the given method is a WailsInit method and if it
+// is, adds it to the list of WailsShutdown methods
+func (d *DB) AddWailsShutdown(method *BoundMethod) error {
+	err := method.VerifyWailsShutdown()
+	if err != nil {
+		return err
+	}
+
+	// Lock the db whilst processing and unlock on return
+	d.lock.Lock()
+	defer d.lock.Unlock()
+
+	d.wailsShutdownMethods = append(d.wailsShutdownMethods, method)
+	return nil
+}
+
+// ToJSON converts the method map to JSON
+func (d *DB) ToJSON() (string, error) {
+
+	// Lock the db whilst processing and unlock on return
+	d.lock.RLock()
+	defer d.lock.RUnlock()
+
+	bytes, err := json.Marshal(&d.store)
+
+	// Return zero copy string as this string will be read only
+	return *(*string)(unsafe.Pointer(&bytes)), err
+}
+
+// WailsInitMethods returns the list of registered WailsInit methods
+func (d *DB) WailsInitMethods() []*BoundMethod {
+	return d.wailsInitMethods
+}
+
+// WailsShutdownMethods returns the list of registered WailsInit methods
+func (d *DB) WailsShutdownMethods() []*BoundMethod {
+	return d.wailsShutdownMethods
+}

internal/binding/parameter.go

@@ -0,0 +1,28 @@
+package binding
+
+import "reflect"
+
+// Parameter defines a Go method parameter
+type Parameter struct {
+	Name        string `json:"name,omitempty"`
+	TypeName    string `json:"type"`
+	reflectType reflect.Type
+}
+
+func newParameter(Name string, Type reflect.Type) *Parameter {
+	return &Parameter{
+		Name:        Name,
+		TypeName:    Type.String(),
+		reflectType: Type,
+	}
+}
+
+// IsType returns true if the given
+func (p *Parameter) IsType(typename string) bool {
+	return p.TypeName == typename
+}
+
+// IsError returns true if the parameter type is an error
+func (p *Parameter) IsError() bool {
+	return p.IsType("error")
+}

internal/binding/reflect.go

@@ -0,0 +1,120 @@
+package binding
+
+import (
+	"fmt"
+	"reflect"
+)
+
+// isStructPtr returns true if the value given is a
+// pointer to a struct
+func isStructPtr(value interface{}) bool {
+	return reflect.ValueOf(value).Kind() == reflect.Ptr &&
+		reflect.ValueOf(value).Elem().Kind() == reflect.Struct
+}
+
+// isStructPtr returns true if the value given is a struct
+func isStruct(value interface{}) bool {
+	return reflect.ValueOf(value).Kind() == reflect.Struct
+}
+
+func getMethods(value interface{}) ([]*BoundMethod, error) {
+
+	// Create result placeholder
+	var result []*BoundMethod
+
+	// Check type
+	if !isStructPtr(value) {
+
+		if isStruct(value) {
+			name := reflect.ValueOf(value).Type().Name()
+			return nil, fmt.Errorf("%s is a struct, not a pointer to a struct", name)
+		}
+
+		return nil, fmt.Errorf("not a pointer to a struct")
+	}
+
+	// Process Struct
+	structType := reflect.TypeOf(value)
+	structValue := reflect.ValueOf(value)
+	baseName := structType.String()[1:]
+
+	// Process Methods
+	for i := 0; i < structType.NumMethod(); i++ {
+		methodDef := structType.Method(i)
+		methodName := methodDef.Name
+		fullMethodName := baseName + "." + methodName
+		method := structValue.MethodByName(methodName)
+
+		// Create new method
+		boundMethod := &BoundMethod{
+			Name:     fullMethodName,
+			Inputs:   nil,
+			Outputs:  nil,
+			Comments: "",
+			Method:   method,
+		}
+
+		// Iterate inputs
+		methodType := method.Type()
+		inputParamCount := methodType.NumIn()
+		var inputs []*Parameter
+		for inputIndex := 0; inputIndex < inputParamCount; inputIndex++ {
+			input := methodType.In(inputIndex)
+			thisParam := newParameter("", input)
+			inputs = append(inputs, thisParam)
+		}
+
+		boundMethod.Inputs = inputs
+
+		// Iterate outputs
+		outputParamCount := methodType.NumOut()
+		var outputs []*Parameter
+		for outputIndex := 0; outputIndex < outputParamCount; outputIndex++ {
+			output := methodType.Out(outputIndex)
+			thisParam := newParameter("", output)
+			outputs = append(outputs, thisParam)
+		}
+		boundMethod.Outputs = outputs
+
+		// Save method in result
+		result = append(result, boundMethod)
+
+	}
+	return result, nil
+}
+
+// convertArgToValue
+func convertArgToValue(input interface{}, target *Parameter) (result reflect.Value, err error) {
+
+	// Catch type conversion panics thrown by convert
+	defer func() {
+		if r := recover(); r != nil {
+			// Modify error
+			err = fmt.Errorf("%s", r.(string)[23:])
+		}
+	}()
+
+	// Do the conversion
+
+	// Handle nil values
+	if input == nil {
+		switch target.reflectType.Kind() {
+		case reflect.Chan,
+			reflect.Func,
+			reflect.Interface,
+			reflect.Map,
+			reflect.Ptr,
+			reflect.Slice:
+			result = reflect.ValueOf(input).Convert(target.reflectType)
+		default:
+			return reflect.Zero(target.reflectType), fmt.Errorf("Unable to use null value")
+		}
+	} else {
+		result = reflect.ValueOf(input).Convert(target.reflectType)
+	}
+
+	// We don't like doing this but it's the only way to
+	// handle recover() correctly
+	return
+
+}