I added the Facebook sdk code to my project then I got this error because I already had a json library, so I deleted the Facebook json library from my computer and from the project but I still get this error. I search the whole project for "#interface SBJsonBase" and I only get one result. How can it say it's a duplicate when I only have one interface? Is it including the file twice? Does the search not always find everything?
May be this helps? Delete your derived data and do a clean project, then try to build again
I had a simular problem. It was a small search, but I could solve it without creating a new project etc...
The thing was I had a Class B that was importing Class A.
Then I had a class that imported Class B and also Class A.
When I did this, these problems occured.
Eg. A SOAP webservice Class imports all the Entities that are passed over the web.
Class goToSchoolWebservice.
import "person.h"
import "school.h"
...
Then I had a Singleton class used for caching that had the Logged in Person and also a ref to the webservice class.
import "person.h"
import "goToSchoolWebservice.h"
--> this is where is went wrong!!
So watch out for these circular references. ITs not so easy to detect them!
if your using #include instead of import then use this technique to minimize duplicates: at the begining of your interface (actually right before it) do check for a definition and if not defined then define it and proceed to define your interface. here is an example:
#ifndef __NetworkOptionsViewController__H // check if this has every been imported before
#define __NetworkOptionsViewController__H
#import "blahblah.h"
#interface NetworkOptionsViewController : UITableViewController
{
NSMutableArray* somevariable1;
int somevariable2;
}
#end
#endif
-- for me personally, i got this error though because the file path to my class was wrong. I checked file inspector and my class file was not defined in Classes folder even though the IDE said it was. I deleted them and copied them over again.
For those that still get this error, despite following header import conventions: I got this error from importing a header that had been deleted from the project. The missing header was instead found in an old backup of my project in dropbox (That I made before doing some destructive stuff in Git), and that file caused the circular import.
I solved a similar problem by moving all the imports to the prefix header file.
Related
I'm facing an issue where I'm trying to split the code up into different files (to make it neater). So far the import is working except for one file.
Currently, my flutter project is setup in this manner
However, one of my files is not importing correctly.
This is my chorusSearch.dart file:
I've tried importing a class from chorusPage.dart. But the import is not resolving.
What is wrong here? This is my chorusPage.dart file.
You cannot call a method or a function of a class that should be instantiated.
You are trying to access a method inside a private class (with the _ char before) of a class that should be initialized before.
If you want to create functions that don't require a view, a page and nothing visual you should make public and static classes and create something like an utility.dart class that contains them.
Then you can call Utility.yourfunction() from where you want
A little example
file utility.dart in lib/utils/
void your_method() {
//do something
}
then in place you can import the file utility.dart and you can also assign to it a name with "as" like this -> import 'package:appname/utils/utility.dart' as Utility;
then you can use Utility.your_method()
For example, I have two files called file1.swift and file2.swift.
file1.swift:
import UIKit
class A: B {
}
file2.swift:
import UIKit
class C: A{
}
I am reading that public class can not subclassed outside of module. Here I have subclass C. I am trying to understand what does module mean here. I imported to same module UIKit for both file. So the both files are of same module? So that I can subclassed. Or both files have different module even I import the same UIKit?
Can anybody explain what is module?
Source:
Classes with public access, or any more restrictive access level, can be subclassed only within the module where they’re defined.
Class members with public access, or any more restrictive access level, can be overridden by subclasses only within the module where they’re defined.
A module is a single unit of code distribution—a framework or application that is built and shipped as a single unit and that can be imported by another module with Swift’s import keyword.
Each build target (such as an app bundle or framework) in Xcode is treated as a separate module in Swift. If you group together aspects of your app’s code as a stand-alone framework—perhaps to encapsulate and reuse that code across multiple applications—then everything you define within that framework will be part of a separate module when it’s imported and used within an app, or when it’s used within another framework.
As the docs indicate, the module is an application or a framework (library). If you create a project with classes A and B, they are part of the same module. Any other class in the same project can inherit from those classes. If you however import that project to another project, classes from that another project won't be able to subclass A nor B. For that you would have to add open indicator before their declarations.
Basically, if you work on a single app then you are working in one single module and unless declared as private or fileprivate, the classes can subclass each other.
EDIT
Let us have following class in module (project) Module1:
class A {
}
Since this class is not open, it can be subclassed only within the same module. That means that following class:
class B: A {
}
Can be written only in the same project, in Module1.
If you add Module1 as a dependency to project Module2, and try to do this:
import Module1
class C: A {
}
It will not compile. That's because class A is not open (in other words it has access public or less) and it does not belong to the same module as C. A belongs to Module1, C belongs to Module2.
Note
import keyword imports a dependency module to your current module. If you write import UIKit in your project, you are telling the compiler that you want to use module UIKit in your module. import does not define current module. Current module is the current project.
Adding import UIKit at the beginning of the file does not change nor define to which module the file belongs. It just tells the compiler that in that file you want to use code from UIKit module.
Swift module(.swiftmodule)
History:
[#include -> #import] -> [Precompiled Headers .pch] -> [#import Module(ObjC);] -> import Module(Swift)
There are two type of Module - folder and file
.swiftmodule folder. Folder contains all .swiftmodule files for architectures and other meta information like:
.swiftmodule file. It is binary file format which contains Abstract Syntax Tree(AST) or Swift Intermediate Language(SIL) of framework's public API.
.swiftdoc - attached docs which can be revived by consumer
.swiftinterface - Module stability
[.swiftinterface or Swift Module Interfaces] is a next step of improving closed source compatibility
When you Jump to Definition of imported module actually you reviewing public interface of .modulemap
Binary(library, framework) can contains several modules, each module can contains a kind of submodule(from Objective-C world) thought.
import struct SomeModule.SomeStruct
These modules can have dependencies between each others.
Module is a set of source files which solves the same problem that is why they can be grouped under the same model name.
Module helps to group sources to reuse them
Module helps Xcode to minimize build time(open source)(If module was not changed it should not been recompiled)
Also Module is a kind of scope which can help compiler to figure out which exactly class to use. If two modules use the same name you get
Ambiguous use of 'foo()'
It can be solved by:
import ModuleName1
import ModuleName2
func someFunc() {
ModuleName1.SomeClass.foo()
ModuleName2.SomeClass.foo()
}
Note: This is a different question than importing generic swift files (which can be done using the Sources folder).
I have a playground with 2 pages and I would like to use a protocol defined in the first page in the second page. I'll use an example of JSON conversion.
JSON.xcplaygroundpage
import Foundation
protocol JSONConvertible {
func jsonValue() -> String
}
JSONArray.xcplaygroundpage
import Foundation
//Undeclared type JSONConvertible
extension Array : JSONConvertible {
}
I have tried the following imports:
import MyPlayground
import MyPlayground.JSON
import JSON
import JSON.Contents (in finder the file name is actually Contents.swift)
I have also tried adding JSON.xcplaygroundpage into the Source folder of JSONArray as well as the Resources folder.
Note: I realize that I could put the protocol definition in a separate JSON.swift and include that in my project Sources folder. That doesn't really answer my question.
This is working in Xcode 8.3.3.
For code common to multiple pages, put it in separate files under top-level Sources group. Be sure to have proper Swift access control keywords in the right places.
Note from http://help.apple.com/xcode/mac/8.2/#/devfa5bea3af:
...the auxiliary Swift source file must export it using the public keyword. This includes classes, methods, functions, variables, and protocols.
Common.swift:
public class DoIExist { public init(){ print("Woot!")} }
Then you can reference it in all of the other pages. Like this:
Page2:
//: [Previous](#previous)
let d = DoIExist()
//: [Next](#next)
You can see that it works because of the console output ("Woot!") and the view results gutter.
To achieve this, I followed the directions at the Apple Xcode documentation about Playgrounds. When Apple inevitably moves those docs and does not provide a forwarding link, read on for how I found it.
I searched for the clues found in the link in cocoapriest's answer: "ios recipes Playground Help Add Auxilliary Code to a Playground". This leads to a document Apple is currently calling "Xcode Help" in a chapter titled "Use playgrounds" in a section titled "Add auxiliary code to a playground".
Just got this to work with this instruction by Apple: https://developer.apple.com/library/ios/recipes/Playground_Help/Chapters/AddAuxilliaryCodetoaPlayground.html
Make sure to declare your classes are public. Also, I had to re-start the Xcode to take the effect.
If I have a structure:
/app/views/tags/tag1.scala.html
/app/views/mystuff/tags/tag2.scala.html
Then, inside tag2.scala.html
#import tags._ // this refers to /app/views/mystuff/tags
#import _root_.tags._ // I want it refers to /app/views/tags
Then I have an error: object tags is not a member of package
Q: what is the best practice to handle imports if the view-structure is deeper than one level ?
REMARK:
I've already read that _root_ can not be imported. But how can I refer to the root then?
UPDATE:
If I try this (not to use root):
#import views.tags._
#import views.mystuff.tags._
Then I have error: object tags is not a member of package views
For now I follow different structure:
tags/tag1.scaa.html
tags/mystuff/tag2.scala.html
and this of course works (maybe this is even better).
Another idea is to create separate play module. Or even different (rest) application.. depending on what 'stuff' is in each concrete case.
So this is alternative solution, I don't know how to refer to root in that case:
The package "views" need to be the last in structure path, so you must change your structure from:
/app/views/mystuff/tags/tag2.scala.html
to:
/app/mystuff/tags/views/tag2.scala.html
I have an ASP.NET 3.5 web application project in which I'm trying to implement a searchable gridview. I originally started the project as a web site and converted it to a web application. After conversion, my class ended up in the folder Old_App_Code and is called SearchGridView.vb.
Imports System
Imports System.Collections
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Text
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Drawing.Design
<Assembly: TagPrefix("MyApp.WebControls", "SearchGridView")>
Namespace MyApp.WebControls
#Region "TemplateColumn"
Public Class NumberColumn
Implements ITemplate
Public Sub InstantiateIn(ByVal container As System.Web.UI.Control) Implements System.Web.UI.ITemplate.InstantiateIn
End Sub
End Class
#End Region
<ToolboxData("<{0}:SearchGridView runat=server></{0}:SearchGridView>")> _
<ParseChildren(True, "SearchFilters")> _
Public Class SearchGridView
Inherits GridView
The class file continues, but this is the first part of it.
Unfortunately, I receive the error message
Warning 1 Namespace or type specified in the project-level Imports 'MyApp.WebControls' doesn't contain any public member or cannot be found. Make sure the namespace or the type is defined and contains at least one public member. Make sure the imported element name doesn't use any aliases. DielWebProj
In web.config, I included a namespace tag for MyApp.WebControls and I included an imports tag in the .aspx page as well.
Can anyone shed light as to why this error is being raised and how I would remedy it?
Thanks,
Sid
I have a broadly similar problem to you. I have a website project using a custom control, inheriting from GriView, in the app_code folder. I was recieving the very same error, but noted that it happened only after I would add a second class or module to app_code, and would disappear if I removed it.
So the workaround I have at the moment is to just leave my custom control as the sole occupant of app_code.
One option might be to make the control part of its own project and add it as a reference to the we site/app?
I'll update this if I can find a decent solution.
EDIT:
Well, in my case it was because the control I was using was written in C#, whereas the rest of the project, and classes I added to app_code, were in VB.
The app_code folder is compiled to a single assembly, so classes of different languages cannot share it, unless you create seperate sub-folders and do some config file jiggerypokery. More details here