i what to know more about SwiftUI, so i decided to make my own functionBuilder.
I made something like this:
public static func buildBlock<Content>(_ contents: Content...) -> Content {
return CombinedContent(with: contents)
}
And it works as expected
But i can't understand what should i do with buidIf function.
Does it should takes optional content and if it's nil return empty View or something?
I would also like to know how does it works under all this abstractions.
Thanks
Related
Problem
I have written some example functions located in a *_test.go file to help clarify context for standalone public functions without issue. The problem on displaying comes when writing example functions for functions tied to a type.
Example
Here's a basic example of what I'm encountering.
Say we have a function in main.go like below:
type Client struct {
user string
ip string
}
func (c *Client) SendNotification(message string) error {
return nil
}
I want to create an example function for such in main_test.go, like below
func ExampleSendNotification() {
//Showoff code here
}
VSCode throws an error for that specific example, saying "ExampleSendNotification refers to unknown identifier: SendNotification". Also, it just does not appear as an example when running the godoc.
I've also tried this format:
func (c *Client) ExampleSendNotification() {
//Showoff code here
}
But then it just removes it as a test in VSCode, and doesn't appear
I found the answer just as I was finishing writing this. Thought I would still post for anybody else.
The trick is writing Example[Type]_[Method], so practically in my example, that would look like:
func ExampleClient_SendNotification() {
//Showoff code here
}
I am currently working on a go project where I define an interface to use in another file. My workflow works but I'm confused at either why there doesn't seem to be any "auto-complete" for protocols or why I cannot find it, I am using VSCode.
First of all, I am not fluent in go at all so if I misuse the term "object" for example that's because I don't know any better.
Let's say the interface looks like that:
type TestInterface interface {
Function1()
}
and my function to pass an object of that interface to looks like that
func Start(obj TestInterface) {
...
Now, in order to define a type that I can construct an object of, I do
type TestInterfaceType int
and because I have to conform to the interface defined, I need to apply these functions to my "new" type
func (e TestInterfaceType) Function1() {
fmt.Println("Test")
}
I am then able to construct an object
var testInterfaceTypeObject TestInterface
testInterfaceTypeObject = TestInterfaceType(1)
and passing that object to my Start() function above which expects a type of that interface works fine since the object of my "new type" has the functions defined that are defined on the interface.
Everything until here works as I have expected, or at least it works for me.
Now if I add another function to the TestInterface but I do not apply that new function to my TestInterfaceType, I see an error coming up that is InvalidIfaceAssign:
InvalidIfaceAssign occurs when a value of type T is used as an
interface, but T does not implement a method of the expected
interface.
I understand why this is happening, I also have to do the func (e TestInterfaceType) ... for my new function but here is my question:
Is there a way to automatically generate empty mock functions for the missing functions? In Java for example, the IDE offers me to add the missing functions (without functionality of course, but at least they are there, ready for me to write logic into them)?
In other words, once I add Function2() to TestInterface, can I make it automatically do
func (e TestInterfaceType) Function2() {
}
wherever I use that interface?
I need to check for fullscreen support with my Go WASM Canvas project, before switching to fullscreen mode. I have the following code so far:
var fullscreenFunc js.Value
var fullscreenNotSupported bool
set with the following logic:
fullscreenFunc = app.Get("requestFullscreen")
if fullscreenFunc.IsUndefined() {
fullscreenFunc = app.Get("mozRequestFullScreen")
if fullscreenFunc.IsUndefined() {
fullscreenFunc = app.Get("webkitRequestFullscreen")
if fullscreenFunc.IsUndefined() {
fullscreenFunc = app.Get("msRequestFullscreen")
if fullscreenFunc.IsUndefined() {
fullscreenNotSupported = true
println("Fullscreen not supported")
}
}
}
}
I was expecting to be able to call the correct function with js.Invoke, but I see no way to tell the Invoke upon which object the call should be made. My 'app' value is being interpreted just as a param.
func Fullscreen(app js.Value) {
if fullscreenNotSupported {
return
}
fullscreenFunc.Invoke(app)
}
resulting in:
panic: JavaScript error: 'mozRequestFullScreen' called on an object that does not implement interface Element.
So am I correct in my thinking that the only way I can call the correct method, is not to store the Function, but to store a string of the function name, and then 'invoke' / 'call' it using the following approach?
app.Call(fullscreenFunctionNameString)
It feels like I misunderstood the purpose of Invoke. Is it only for js.Global() type calls?
[edit] Using 'Call', at least it seems possible to derive the function name without having to repeat the above browser specifics:
fullscreenFunctionName = fullscreenFunc.Get("name").String()
app.Call(fullscreenFunctionNameString)
It doesn't answer the question, but is probably of help to someone trying to do the same.
The arguments to invoke get turned into arguments for the javascript function it wraps. Since those fullscreen functions don't need any arguments, I think you might just need to change:
fullscreenFunc.Invoke(app)
To:
fullscreenFunc.Invoke()
...assuming app is the same JS element in both places. If not your Call solution is probably your best bet.
I see a lot of codes like this in the golang src:
func Open(path string) (*Plugin, error) {
return open(path)
}
func open() {
// etc
}
A private function been called from a public. Why not just:
func Open(path string) (*Plugin, error) {
// code of open here
}
ref: https://golang.org/src/plugin/plugin.go?s=1065:1104#L21
I do understand that sometimes it makes sense, especially if there are more functions using open. But that's not the case.
Is this some kind of Golang way of organizing things?
In this case, it appears to be because the actual implementation is OS dependent.
The plugin implementation plugin_dlopen.go is used only for OSX and Linux, and the alternative plugin_stubs.go is for everything else(which just contains dummy functions as there is no implementation for other systems yet.)
This allows you to keep OS dependent code in one file using build tags, while keeping general code, the public API and documentation for the public API in a single place.
I've been experimenting with Swift on my way home from WWDC. One of the most compelling new features of Swift, in my opinion, was namespacing. I haven't managed to get it to work as I expected it should though. Please see the attached screenshot and let me know if you have an idea of what I'm doing wrong.
EDIT: I have of course tried to remove the import statement.
Turns out that this is a known bug: https://devforums.apple.com/message/976286#976286
I am sorry, if I search for "namespace" or "namespacing" in the Swift-eBook there are no results. Maybe you can give me a link to an additional resource?
I would solve your problem simply with a struct and static functions.
ClassA
struct ClassA {
static func localize() {
println("Localized String")
}
}
ClassB
You can drop the import and execute the ClassA-function as follows:
ClassA.localize()
The second way
In your case you can also just make an extension of String like so:
extension String {
func localize() -> String {
return self+"-localized"
}
}
println("Test".localize()) // prints "Test-localized"