Documentation

Overview

    Package js is a drop-in replacement for syscall/js that provides identical behavior in a WebAssembly environment, and useful non-functional behavior outside of WebAssembly.

    To use it, simply import this package instead of "syscall/js" and use it in exactly the same way. Your code will compile targeting either wasm or non-wasm environments. In wasm, the functionality is exactly the same, the calls and types are delegated directly to "syscall/js". The compiler will optimize away virtually (if not literally) all of the overhead associated with this aliasing. When run outside of wasm, appropriate functionality indicates that the environment is not availble: All js.Value instances are undefined. Global(), Value.Get() always return undefined. Value.Call(), FuncOf() and other such functions will panic. Value.Truthy() will always return false. For example, Global().Truthy() can be used to determine if the js environment is functional.

    Rationale: Since syscall/js is only available when the GOOS is "js", this means programs which run server-side cannot access that package and will fail to compile. Since Vugu components are inherently closely integrated with browsers and may often need to do things like declare variables of type js.Value, this is a problem for components which are rendered not only in wasm client-side but also server-side. Build tags can be used to provide multiple implementations of a components but this can become tedious.

    Usually what you want is that the majority of your code which is not js-specific can be written once and execute in the browser or on the server, and the relatively small amount of functionality that is uses "js" will compile properly in both environments but just not be executed on the server. Or allow for if statements to easily disable functionality not available server-side. That's what this package provides.

    Index

    Constants

    This section is empty.

    Variables

    This section is empty.

    Functions

    func CopyBytesToGo

    func CopyBytesToGo(dst []byte, src Value) int

      CopyBytesToGo placeholder for syscall/js

      func CopyBytesToJS

      func CopyBytesToJS(dst Value, src []byte) int

        CopyBytesToJS placeholder for syscall/js

        Types

        type Error

        type Error struct {
        	Value
        }

          Error placeholder for syscall/js

          func (Error) Error

          func (e Error) Error() string

            Error placeholder for syscall/js

            type Func

            type Func struct {
            	Value
            }

              Func placeholder for syscall/js

              func FuncOf

              func FuncOf(fn func(Value, []Value) interface{}) Func

                FuncOf placeholder for syscall/js

                func (Func) Release

                func (c Func) Release()

                  Release placeholder for syscall/js

                  type Type

                  type Type int

                    Type placeholder for syscall/js

                    const (
                    	TypeUndefined Type = iota
                    	TypeNull
                    	TypeBoolean
                    	TypeNumber
                    	TypeString
                    	TypeSymbol
                    	TypeObject
                    	TypeFunction
                    )

                      Placeholder for syscall/js

                      func (Type) String

                      func (t Type) String() string

                        String placeholder for syscall/js

                        type Value

                        type Value struct {
                        	// contains filtered or unexported fields
                        }

                          Value placeholder for syscall/js

                          func Global

                          func Global() Value

                            Global placeholder for syscall/js

                            func Null

                            func Null() Value

                              Null placeholder for syscall/js

                              func Undefined

                              func Undefined() Value

                                Undefined placeholder for syscall/js

                                func ValueOf

                                func ValueOf(x interface{}) Value

                                  ValueOf placeholder for syscall/js

                                  func (Value) Bool

                                  func (v Value) Bool() bool

                                  func (Value) Call

                                  func (v Value) Call(m string, args ...interface{}) Value

                                  func (Value) Float

                                  func (v Value) Float() float64

                                  func (Value) Get

                                  func (v Value) Get(p string) Value

                                  func (Value) Index

                                  func (v Value) Index(i int) Value

                                  func (Value) InstanceOf

                                  func (v Value) InstanceOf(t Value) bool

                                  func (Value) Int

                                  func (v Value) Int() int

                                  func (Value) Invoke

                                  func (v Value) Invoke(args ...interface{}) Value

                                  func (Value) IsNull

                                  func (v Value) IsNull() bool

                                  func (Value) IsUndefined

                                  func (v Value) IsUndefined() bool

                                  func (Value) JSValue

                                  func (v Value) JSValue() Value

                                    JSValue placeholder for syscall/js

                                    func (Value) Length

                                    func (v Value) Length() int

                                    func (Value) New

                                    func (v Value) New(args ...interface{}) Value

                                    func (Value) Set

                                    func (v Value) Set(p string, x interface{})

                                    func (Value) SetIndex

                                    func (v Value) SetIndex(i int, x interface{})

                                    func (Value) String

                                    func (v Value) String() string

                                    func (Value) Truthy

                                    func (v Value) Truthy() bool

                                    func (Value) Type

                                    func (v Value) Type() Type

                                      Type placeholder for syscall/js

                                      type ValueError

                                      type ValueError struct {
                                      	Method string
                                      	Type   Type
                                      }

                                        ValueError placeholder for syscall/js

                                        func (*ValueError) Error

                                        func (e *ValueError) Error() string

                                          Error placeholder for syscall/js

                                          type Wrapper

                                          type Wrapper interface {
                                          	JSValue() Value
                                          }

                                            Wrapper placeholder for syscall/js