Swift class from string that uses generics
I am trying to instantiate a class from string, but it is not working because of generics.
I have this class declaration:
class PollSummaryView<T: PollSummary>: UIView {}
And then many subclasses:
class TextPollSummaryView: PollSummaryView<TextPollSummary> {}
class ChartingPollSummaryView: PollSummaryView<ChartPollSummary> {}
Then, I am trying to instantiate doing this:
let contentClassName = "(summary.poll.type.rawValue)PollSummaryView"
let contentClass = classFromString(contentClassName) as? PollSummaryView.Type
But it is getting nil. Also tried this with same results:
let contentClassName = "(summary.poll.type.rawValue)PollSummaryView"
let contentClass = classFromString(contentClassName) as? PollSummaryView<PollSummary>.Type
Just in case, this the classFromString snippet:
func classFromString(_ className: String) -> AnyClass? {
let namespace = Bundle.main.infoDictionary!["CFBundleExecutable"] as! String;
let cls: AnyClass? = NSClassFromString("(namespace).(className)");
return cls;
}
In Java Android I am doing this:
public static @Nullable
<T extends PollSummaryView> T createView(PollSummary summary, Context context) {
try {
String simpleClassName = StringUtils.capitalize(summary.getPoll().getType().name()).concat("PollSummaryView");
String className = String.format("%s.%s", getPackage(), simpleClassName);
Class<? extends PollSummaryView> clazz = Class.forName(className).asSubclass(PollSummaryView.class);
return (T) clazz.getConstructor(summary.getClass(), Context.class).newInstance(summary, context);
} catch (Exception e) {
return null;
}
}
And it works, but warning about an unchecked cast.
Is there any Swift expert over there?
Many thanks!
swift generics reflection
asked Nov 20 at 17:32
Matias Cohen
11
add a comment |
I am trying to instantiate a class from string, but it is not working because of generics.
I have this class declaration:
class PollSummaryView<T: PollSummary>: UIView {}
And then many subclasses:
class TextPollSummaryView: PollSummaryView<TextPollSummary> {}
class ChartingPollSummaryView: PollSummaryView<ChartPollSummary> {}
Then, I am trying to instantiate doing this:
let contentClassName = "(summary.poll.type.rawValue)PollSummaryView"
let contentClass = classFromString(contentClassName) as? PollSummaryView.Type
But it is getting nil. Also tried this with same results:
let contentClassName = "(summary.poll.type.rawValue)PollSummaryView"
let contentClass = classFromString(contentClassName) as? PollSummaryView<PollSummary>.Type
Just in case, this the classFromString snippet:
func classFromString(_ className: String) -> AnyClass? {
let namespace = Bundle.main.infoDictionary!["CFBundleExecutable"] as! String;
let cls: AnyClass? = NSClassFromString("(namespace).(className)");
return cls;
}
In Java Android I am doing this:
public static @Nullable
<T extends PollSummaryView> T createView(PollSummary summary, Context context) {
try {
String simpleClassName = StringUtils.capitalize(summary.getPoll().getType().name()).concat("PollSummaryView");
String className = String.format("%s.%s", getPackage(), simpleClassName);
Class<? extends PollSummaryView> clazz = Class.forName(className).asSubclass(PollSummaryView.class);
return (T) clazz.getConstructor(summary.getClass(), Context.class).newInstance(summary, context);
} catch (Exception e) {
return null;
}
}
And it works, but warning about an unchecked cast.
Is there any Swift expert over there?
Many thanks!
swift generics reflection
asked Nov 20 at 17:32
Matias Cohen
11
add a comment |
I am trying to instantiate a class from string, but it is not working because of generics.
I have this class declaration:
class PollSummaryView<T: PollSummary>: UIView {}
And then many subclasses:
class TextPollSummaryView: PollSummaryView<TextPollSummary> {}
class ChartingPollSummaryView: PollSummaryView<ChartPollSummary> {}
Then, I am trying to instantiate doing this:
let contentClassName = "(summary.poll.type.rawValue)PollSummaryView"
let contentClass = classFromString(contentClassName) as? PollSummaryView.Type
But it is getting nil. Also tried this with same results:
let contentClassName = "(summary.poll.type.rawValue)PollSummaryView"
let contentClass = classFromString(contentClassName) as? PollSummaryView<PollSummary>.Type
Just in case, this the classFromString snippet:
func classFromString(_ className: String) -> AnyClass? {
let namespace = Bundle.main.infoDictionary!["CFBundleExecutable"] as! String;
let cls: AnyClass? = NSClassFromString("(namespace).(className)");
return cls;
}
In Java Android I am doing this:
public static @Nullable
<T extends PollSummaryView> T createView(PollSummary summary, Context context) {
try {
String simpleClassName = StringUtils.capitalize(summary.getPoll().getType().name()).concat("PollSummaryView");
String className = String.format("%s.%s", getPackage(), simpleClassName);
Class<? extends PollSummaryView> clazz = Class.forName(className).asSubclass(PollSummaryView.class);
return (T) clazz.getConstructor(summary.getClass(), Context.class).newInstance(summary, context);
} catch (Exception e) {
return null;
}
}
And it works, but warning about an unchecked cast.
Is there any Swift expert over there?
Many thanks!
swift generics reflection
asked Nov 20 at 17:32
Matias Cohen
11
I am trying to instantiate a class from string, but it is not working because of generics.
I have this class declaration:
class PollSummaryView<T: PollSummary>: UIView {}
And then many subclasses:
class TextPollSummaryView: PollSummaryView<TextPollSummary> {}
class ChartingPollSummaryView: PollSummaryView<ChartPollSummary> {}
Then, I am trying to instantiate doing this:
let contentClassName = "(summary.poll.type.rawValue)PollSummaryView"
let contentClass = classFromString(contentClassName) as? PollSummaryView.Type
But it is getting nil. Also tried this with same results:
let contentClassName = "(summary.poll.type.rawValue)PollSummaryView"
let contentClass = classFromString(contentClassName) as? PollSummaryView<PollSummary>.Type
Just in case, this the classFromString snippet:
func classFromString(_ className: String) -> AnyClass? {
let namespace = Bundle.main.infoDictionary!["CFBundleExecutable"] as! String;
let cls: AnyClass? = NSClassFromString("(namespace).(className)");
return cls;
}
In Java Android I am doing this:
public static @Nullable
<T extends PollSummaryView> T createView(PollSummary summary, Context context) {
try {
String simpleClassName = StringUtils.capitalize(summary.getPoll().getType().name()).concat("PollSummaryView");
String className = String.format("%s.%s", getPackage(), simpleClassName);
Class<? extends PollSummaryView> clazz = Class.forName(className).asSubclass(PollSummaryView.class);
return (T) clazz.getConstructor(summary.getClass(), Context.class).newInstance(summary, context);
} catch (Exception e) {
return null;
}
}
And it works, but warning about an unchecked cast.
Is there any Swift expert over there?
Many thanks!
swift generics reflection
swift generics reflection
asked Nov 20 at 17:32
Matias Cohen
11
asked Nov 20 at 17:32
Matias Cohen
11
asked Nov 20 at 17:32
Matias Cohen
11
asked Nov 20 at 17:32
Matias Cohen
11
asked Nov 20 at 17:32
Matias Cohen
11
11
add a comment |
add a comment |
active
oldest
votes
Your Answer
StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53398461%2fswift-class-from-string-that-uses-generics%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
active
oldest
votes
active
oldest
votes
active
oldest
votes
active
oldest
votes
Thanks for contributing an answer to Stack Overflow!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Some of your past answers have not been well-received, and you're in danger of being blocked from answering.
Please pay close attention to the following guidance:
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53398461%2fswift-class-from-string-that-uses-generics%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
