swift - Crash casting WKNSURLRequest as? other type -


i'm getting hard crash when try cast wknsurlrequest (and other classes, webkit framework).

e.g. in playground:

import uikit import webkit  final class sigh: nsobject { }  nsclassfromstring("nsobject") as? sigh.type  nsclassfromstring("wknsurlrequest") as? sigh.type

the cast nsobject works (i.e. returns nil), cast wknsurlrequest crashes exc_bad_access - have assumed return nil well.

anyone got ideas might causing this?

wknsurlrequest not inherit nsobject

@interface wknsurlrequest : wkobject <nscopying>

and wkobject root class:

ns_root_class @interface wkobject <wkobject>

unlike java, classes must inerhit object, obj-c not require classes inherit nsobject.

the swift<->obj-c bridge has explicit support nsobject , subclasses, i'm not sure can handle other root objects equally well. on export side (swift classes being exposed obj-c) it's not possible make own root class. swift class shall exposed obj-c must inherit nsobject, i'd bridge has not been designed arbitrary root classes in mind.

of course, none of explains crash, simple bug in swift compiler or swift runtime. don't reference classes statically name, happens @ runtime , swift runtime may assume whatever nsclassfromstring returns subclass of nsobject , when tries interact class, fail @ runtime because assumption plain wrong. in case still bug imho explain why there crash.


Comments

Post a Comment

Popular posts from this blog

javascript - Clear button on addentry page doesn't work -

this addentry blog page have made scratch , there underlying problems code particularly clear button supposed clear text entered when button clicked on doesn't work have saved html file problem. also 1 other problem submit button works doesn't pass of text index file have written php , reason whenever click on submit button redirects me index page without posting entry have made. <!doctype html> <html> <head> <script> function message() { alert("clear form?"); } </script> <style> body {background-color: beige;} h1 {color: black;} p {color: black;} textarea { width: 50%; height: 150px; padding: 12px 20px; box-sizing: border-box; border: 2px solid #ccc; border-radius: 4px; background-color: white; font-size: 16px; resize: none; } div { padding-left: 20px; } </style> </head> <meta charset="utf-8"> <link rel="stylesheet" href=".
Read more

c# - Selenium Authentication Popup preventing driver close or quit -

i have selenium automated task setup login website retrieve information. it's basic in automation. logging in , clicking 2 links. running issue proving problem. the site in question uses authentication required popup not javascript popup rather regular windows auth popup. have read isn't handled out of box selenium. i using " http://username:password@url.com " site every , site has issues on end prompt me again username/password randomly. have enter username/password twice in row when navigating there hand. since task loops continuously few hours picking needed info figured use webdriverwait verify element present on page. if authentication popup appears, element isn't present. no need care run, start over. the problem having when authentication popup displayed , hit timeout limit want close driver/browser window can start task on again. however, driver.close() , driver.quit() not doing anything. browser remains open , unloaded page still there login p
Read more

tensorflow when input_data MNIST_data , zlib.error: Error -3 while decompressing: invalid block type -

i'm geting started tensorflow,followed tutorials,but cannot download mnist data. import tensorflow tf tensorflow.examples.tutorials.mnist import input_data mnist=input_data.read_data_sets("mnist_data/",one_hot=true) print("download done!") error information: extracting mnist_data/train-images-idx3-ubyte.gz traceback (most recent call last): file "/home/sj/program/tesorflow_try.py", line 6, in <module> mnist=input_data.read_data_sets("mnist_data/",one_hot=true) file "/usr/local/lib/python2.7/dist-packages/tensorflow/contrib/learn/python/learn/datasets/mnist.py", line 213, in read_data_sets train_images = extract_images(f) file "/usr/local/lib/python2.7/dist-packages/tensorflow/contrib/learn/python/learn/datasets/mnist.py", line 60, in extract_images buf = bytestream.read(rows * cols * num_images) file "/usr/lib/python2.7/gzip.py", line 268, in read self._read(readsize) file
Read more