Is there a way to do something akin to import <BLAH> as in actionscript? I've got some classes that I don't want to type the full class name out for every time I use them. That's why I'm trying to find an import as, or var C = ImportedClassThatIDontWantToTypeEveryTime. I've tried a few different ways, such as:
package com.mysite.blah {
// doesn't work
import com.mysite.ImportedClassThatIDontWantToTypeEveryTime as C;
// also doesn't work
import com.mysite.ImportedClassThatIDontWantToTypeEveryTime;
var C:Class = ImportedClassThatIDontWantToTypeEveryTime;
// ????
public class SomeOtherClass {
public function blah():void {
C.doSomething();
}
}
}
I know there is a way to do this - I've done it before years ago. However, I can't remember how to do it. Help?
What IDE are you using? I ask this because I haven't had to type out a class-path in full in years. The auto-complete features of both FlashDevelop and FlashBuilder will allow you to type the first couple of letters of the class you want in place, select it from a list, and it will automatically add the appropriate import statement to the top of your class.
Related
I have been asked to do testing in swift and I have no idea about swift
So, I was just reviewing the code and trying to make sense out of it.
I was in a file say xyzTests.swift where we wrote all the test case.
By going through the test cases written in the code, the first thing was something like this
func xyz() {
var failureMessage: String? = nil;
startSess(validity: 3)
}
In Javascript,one can only do something like this if
There is a function declared anywhere in the same file
if we are importing it from somewhere
So I searched in my file to find function declaration from startSess but wasn't able to find it. Then I clicked on jump to definition and found it some other file named utils.swift
internal func startSess(validity: Int = 1) {
}
I checked the file if there was at-least a reference of an import for at-least util but can't find any.
These are all the import statements in my code
import Foundation
#testable import session
Can someone explain me how we can use startSess?
I take it that the startSess is a function that is outside of any class then as it's being called in that way?
what #testable import session does is importing your entire workspace to be reachable from your test class. If you look in the right tab of the test file you can see that the target membership is only selected for tests (as it should be). And therefor it can't reach the rest of your code without the #testable import
See, There are various different methods to call a function from another file Some of them are as given below
(and Pardon me if I left any methods in this answer, I am open to edits :) )
As #Vollan said , importing the whole workspace , so you can access any function from any file anywhere in the project
Calling or Loading the file (in your case util.swift) and using the function in another file(xyz.swift)
ex: In xyz.swift,
func xyz() {
let a = util() //Loading the swiftfile
a.startSess(validity: 3) //using the function of swiftfile
}
making that function global which you want to use.
extension UIViewController { //In most cases UIViewController is used in all files so extending it helps
func startSess(validity: Int = 1) {
}
}
You can directly make that function global even if you are not using any extensions or any classes by using Foundation(As in any file Foundation is must imported in the Header of any SwiftFile)
Ex: - Make any SwiftFile say named abc.swift and in that file
import Foundation
func startSess(validity: Int = 1) {
//Your Code
}
Now, you can call this function by startSess(param) in any file in your whole project.
Should I get the following error:
class.dart:11:11: Error: The getter '_privateID' isn't defined for the class 'Y'.
- 'Y' is from 'class.dart'.
Try correcting the name to the name of an existing getter, or defining a getter or field named '_privateID'.
From the following code?
mixin.dart:
class Mixin {
static int _nextID = 0;
int publicID = _nextID++; // I only need one of these lines
int _privateID = _nextID++; // but this variable is inaccessible
}
class.dart:
import 'mixin.dart';
class X with Mixin {
void run() {
print(publicID); // no error here
}
}
class Y with Mixin {
void run() {
print(_privateID); // Error: _privateID not defined
}
}
void main() {
Y().run();
}
Or is this a bug? If it's not a bug, I'd like to understand why this behavior is reasonable.
When I instead define the mixin in the same file as the above classes, I get no error.
(Dart SDK 2.4.1.)
It is not a bug.
The private field is inherited, but you cannot access it because its name is private to a different library.
Dart's notion of "privacy" is library private names.
The name _privateID in the mixin.dart library introduces a library private name. This name is special in that it can only be written inside the same library.
If someone writes _privateID in a different library, it is a different name, one unique to that library instead.
It is as if private names includes the library URI of the library it is written in, so what you really declare is a name _privateID#mixin.dart.
When you try to read that field in class.dart, you write ._privateID, but because it is in a different library, what you really write is ._privateID#class.dart, a completely different name, and the classs does not have any declarations with that name.
So, if one class needs to access a private member of another class (or mixin, or anything), then the two needs to be declared in the same library, because otherwise they cannot even write the name of that variable.
That is why the code works if you write the mixin in the same library.
If you want to move the mixin to a separate file, but not necessarily a separate library, you can use a part file.
I had one custom parser rule in which I had defined all my keywords such as _self, _for, _loop etc. Because of this, if I type _s and click Ctrl+ space bar, it shows _self.But what I required is even though I type self or SE, it should auto assign as _self.Is it possible? If so, could anyone please suggest a solution for this. Thanks in advance
There are multiple things to be payed attention to
There needs to be a proposal and only one proposal. Otherwise the user has to select the prosal to be applied and no auto insert takes places
Proposals are created based on the error recovery and so you might not get the proposal you are looking for at all
so lets assume you have a grammar like
Model:
greetings+=Greeting*;
Greeting:
'_self' name=ID '!';
and a model file like
SE
Then the error recovery will work fine an a proposal of "_self" will be added to the list of proposals
Proposals are Filtered based on the current prefix in the model. that would be the place you could start customizing.
e.g. this very naive impl
import org.eclipse.xtext.ui.editor.contentassist.FQNPrefixMatcher;
public class MyPrefixMatcher extends FQNPrefixMatcher {
#Override
public boolean isCandidateMatchingPrefix(String name, String prefix) {
return super.isCandidateMatchingPrefix(name, prefix) || super.isCandidateMatchingPrefix(name, "_" + prefix);
}
}
and dont forget to bind
import org.eclipse.xtend.lib.annotations.FinalFieldsConstructor
import org.eclipse.xtext.ui.editor.contentassist.PrefixMatcher
import org.xtext.example.mydsl4.ui.contentassist.MyPrefixMatcher
#FinalFieldsConstructor
class MyDslUiModule extends AbstractMyDslUiModule {
override Class<? extends PrefixMatcher> bindPrefixMatcher() {
return MyPrefixMatcher;
}
}
There is another feature that does not use proposals at all but the text that is actually typed and if it recognizes something then can replace it with something else. this feature is called "Auto Edit". The extension point in xtext for this is IAutoEditStrategy / AbstractEditStrategyProvider
Is it possible to set HTML5 attribute autocomplete="off" on TextField in Vaadin 7?
I've searched but found no way to set attributes on text fields or just hint browser to disable native autocompletion on input fields in some other way in vaadin.
I think the only way if you use javascript:
TextField tf = new TextField();
tf.addStyleName("xyz");
JavaScript.getCurrent().execute(
"document.getElementsByClassName('xyz')[0].setAttribute('autocomplete', 'off')");
Extend the TextField...
package com.example;
import com.vaadin.ui.TextField;
public class MyTextField extends TextField {
// do other customization here as needed
}
...and - what's the key point here - its client-side Connector
package com.example.client;
import com.vaadin.client.ui.VTextField;
import com.vaadin.client.ui.textfield.TextFieldConnector;
import com.vaadin.shared.ui.Connect;
#Connect(com.example.MyTextField.class)
public class MyTextFieldConnector extends TextFieldConnector {
#Override
public VTextField getWidget() {
VTextField vTextField = super.getWidget();
vTextField.getElement().setAttribute("autocomplete","off");
return vTextField;
}
}
Don't forget to recompile the widget set.
If you use the Viritin add-on, you can now use the HtmlElementPropertySetter class to wrap your TextField component and use that to set the "autocomplete" element property to "off". You could also use the MTextField component that comes with Viritin and just create it as follows:
MTextField username = new MTextField("Username")
.withAutocompleteOff();
This is an extension to #Wojciech Marciniak's answer. His approach worked for me, but I want to note a couple or three modifications I had to do in order for it to work as of 2017/11/28.
1) autocomplete="off" don't seem to work anymore nowadays; at least not on Chrome. Instead, you can use autocomplete="new-password", which works on Chrome 62.0.3202.94 windows 64 bits. I also noticed some inconsistent behaviour with this attribute, as NOT always works - sometimes a list with choices for passwords will show up on the component (specially until you refresh a couple of times, etc.).
2a) Instead of extending the component, you may want to overwrite it by creating the com.vaadin.client.ui.(component)field package in your project, then put the modified (component)FieldConnector.java file in it (in my case I was modifying PasswordField) in case you want all your instances of this component to not remember passwords. The final class source should look like this:
package com.vaadin.client.ui.passwordfield;
import com.vaadin.client.ui.VPasswordField;
import com.vaadin.client.ui.textfield.TextFieldConnector;
import com.vaadin.shared.ui.Connect;
import com.vaadin.ui.PasswordField;
#Connect(PasswordField.class)
public class PasswordFieldConnector extends TextFieldConnector {
#Override
public VPasswordField getWidget() {
VPasswordField vTextField = (VPasswordField) super.getWidget();
vTextField.getElement().setAttribute("autocomplete","new-password");
return vTextField;
}
}
So this way you don't need any other class extending TextField (or PasswordField).
2b) If you want to allow some fields to remember passwords and other that don't, you can extend the component and use your preferred component accordingly. You can keep your connector class as in 2a) but remember to name it something like CustomPasswordFieldConnector, and it should also #Connect with that CustomPasswordField.class, put that class wherever it fits in your project and remember to add the proper import for it in the connector in case it's needed. This class is just a dummy one - you can leave its contents empty in case you don't need any extra functionality (but remember it should extend the proper (component)Field; PasswordField in the example).
The documentation only mentions nested types, but it's not clear if they can be used as namespaces. I haven't found any explicit mentioning of namespaces.
I would describe Swift's namespacing as aspirational; it's been given a lot of advertising that doesn't correspond to any meaningful reality on the ground.
For example, the WWDC videos state that if a framework you're importing has a class MyClass and your code has a class MyClass, those names do not conflict because "name mangling" gives them different internal names. In reality, however, they do conflict, in the sense that your own code's MyClass wins, and you can't specify "No no, I mean the MyClass in the framework" — saying TheFramework.MyClass doesn't work (the compiler knows what you mean, but it says it can't find such a class in the framework).
My experience is that Swift therefore is not namespaced in the slightest. In turning one of my apps from Objective-C to Swift, I created an embedded framework because it was so easy and cool to do. Importing the framework, however, imports all the Swift stuff in the framework - so presto, once again there is just one namespace and it's global. And there are no Swift headers so you can't hide any names.
EDIT: In seed 3, this feature is now starting to come online, in the following sense: if your main code contains MyClass and your framework MyFramework contains MyClass, the former overshadows the latter by default, but you can reach the one in the framework by using the syntax MyFramework.MyClass. Thus we do in fact have the rudiments of a distinct namespace!
EDIT 2: In seed 4, we now have access controls! Plus, in one of my apps I have an embedded framework and sure enough, everything was hidden by default and I had to expose all the bits of the public API explicitly. This is a big improvement.
Answered by SevenTenEleven in the Apple dev forum:
Namespaces are not per-file; they're per-target (based on the
"Product Module Name" build setting). So you'd end up with something
like this:
import FrameworkA
import FrameworkB
FrameworkA.foo()
All Swift declarations are considered to be part of
some module, so even when you say "NSLog" (yes, it still exists)
you're getting what Swift thinks of as "Foundation.NSLog".
Also Chris Lattner tweeted about namespacing.
Namespacing is implicit in Swift, all classes (etc) are implicitly
scoped by the module (Xcode target) they are in. no class prefixes
needed
Seems to be very different what I have been thinking.
While doing some experimentation with this I ended up creating these "namespaced" classes in their own files by extending the root "package". Not sure if this is against best practices or if it has any implications I'm mot aware of(?)
AppDelegate.swift
var n1 = PackageOne.Class(name: "Package 1 class")
var n2 = PackageTwo.Class(name: "Package 2 class")
println("Name 1: \(n1.name)")
println("Name 2: \(n2.name)")
PackageOne.swift
import Foundation
struct PackageOne {
}
PackageTwo.swift
import Foundation
struct PackageTwo {
}
PackageOneClass.swift
extension PackageOne {
class Class {
var name: String
init(name:String) {
self.name = name
}
}
}
PackageTwoClass.swift
extension PackageTwo {
class Class {
var name: String
init(name:String) {
self.name = name
}
}
}
Edit:
Just found out that creating "subpackages" in above code wont work if using separate files. Maybe someone can hint on why that would be the case?
Adding following files to the above:
PackageOneSubPackage.swift
import Foundation
extension PackageOne {
struct SubPackage {
}
}
PackageOneSubPackageClass.swift
extension PackageOne.SubPackage {
class Class {
var name: String
init(name:String) {
self.name = name
}
}
}
Its throwing a compiler error:
'SubPackage' is not a member type of 'PackageOne'
If I move the code from PackageOneSubPackageClass.swift to PackageOneSubPackage.swift it works. Anyone?
Edit 2:
Fiddling around with this still and found out (in Xcode 6.1 beta 2) that by defining the packages in one file they can be extended in separate files:
public struct Package {
public struct SubPackage {
public struct SubPackageOne {
}
public struct SubPackageTwo {
}
}
}
Here are my files in a gist:
https://gist.github.com/mikajauhonen/d4b3e517122ad6a132b8
I believe this is achieved using:
struct Foo
{
class Bar
{
}
}
Then it can be accessed using:
var dds = Foo.Bar();
Namespaces are useful when you need to define class with the same name as class in existing framework.
Suppose your app has MyApp name, and you need to declare your custom UICollectionViewController.
You don't need to prefix and subclass like this:
class MAUICollectionViewController: UICollectionViewController {}
Do it like this:
class UICollectionViewController {} //no error "invalid redeclaration o..."
Why?. Because what you've declared is declared in current module, which is your current target. And UICollectionViewController from UIKit is declared in UIKit module.
How to use it within current module?
var customController = UICollectionViewController() //your custom class
var uikitController = UIKit.UICollectionViewController() //class from UIKit
How to distinguish them from another module?
var customController = MyApp.UICollectionViewController() //your custom class
var uikitController = UIKit.UICollectionViewController() //class from UIKit
Swift uses modules much like in python (see here and here) and as #Kevin Sylvestre suggested you can also use the nested types as namespaces.
And to extend the answer from #Daniel A. White, in WWDC they were talking about the modules in swift.
Also here is explained:
Inferred types make code cleaner and less prone to mistakes, while
modules eliminate headers and provide namespaces.
You can use extension to use the mentioned structs approach for namespacing without having to indent all of your code towards the right. I've been toying with this a bit and I'm not sure I'd go as far as creating Controllers and Views namespaces like in the example below, but it does illustrate how far it can go:
Profiles.swift:
// Define the namespaces
struct Profiles {
struct Views {}
struct ViewControllers {}
}
Profiles/ViewControllers/Edit.swift
// Define your new class within its namespace
extension Profiles.ViewControllers {
class Edit: UIViewController {}
}
// Extend your new class to avoid the extra whitespace on the left
extension Profiles.ViewControllers.Edit {
override func viewDidLoad() {
// Do some stuff
}
}
Profiles/Views/Edit.swift
extension Profiles.Views {
class Edit: UIView {}
}
extension Profiles.Views.Edit {
override func drawRect(rect: CGRect) {
// Do some stuff
}
}
I haven't used this in an app since I haven't needed this level of separation yet but I think it's an interesting idea. This removes the need for even class suffixes such as the ubiquitous *ViewController suffix which is annoyingly long.
However, it doesn't shorten anything when it's referenced such as in method parameters like this:
class MyClass {
func doSomethingWith(viewController: Profiles.ViewControllers.Edit) {
// secret sauce
}
}
Even though it is possible to implement namespaces using Framework and Libraries but the best solution is to use local packages using Swift Package Manager. Besides having access modifiers, this approach has some other benefits. As in Swift Package Manager, the files are managed based on the directory system, not their target member ship, you won't have to struggle with merge conflicts that arise frequently in teamworks. Furthermore, there is no need to set file memberships.
To check how to use local Swift packages refer to the following link:
Organizing Your Code with Local Packages
In case anyone was curious, as of June 10th 2014, this is a known bug in Swift:
From SevenTenEleven
"Known bug, sorry! rdar://problem/17127940 Qualifying Swift types by their module name doesn't work."