attributes – Page 19

get the value of DisplayName attribute

January 17, 2023 by Tarik

Try these utility methods of mine: using System.ComponentModel; using System.Globalization; using System.Linq; public static T GetAttribute<T>(this MemberInfo member, bool isRequired) where T : Attribute { var attribute = member.GetCustomAttributes(typeof(T), false).SingleOrDefault(); if (attribute == null && isRequired) { throw new ArgumentException( string.Format( CultureInfo.InvariantCulture, “The {0} attribute must be defined on member {1}”, typeof(T).Name, member.Name)); } return … Read more

hasattr() vs try-except block to deal with non-existent attributes

January 15, 2023 by Tarik

Any benches that illustrate difference in performance? timeit it’s your friend $ python -mtimeit -s ‘class C(object): a = 4 c = C()’ ‘hasattr(c, “nonexistent”)’ 1000000 loops, best of 3: 1.87 usec per loop $ python -mtimeit -s ‘class C(object): a = 4 c = C()’ ‘hasattr(c, “a”)’ 1000000 loops, best of 3: 0.446 usec … Read more

Can’t set attributes on instance of “object” class

January 15, 2023 by Tarik

To support arbitrary attribute assignment, an object needs a __dict__: a dict associated with the object, where arbitrary attributes can be stored. Otherwise, there’s nowhere to put new attributes. An instance of object does not carry around a __dict__ — if it did, before the horrible circular dependence problem (since dict, like most everything else, … Read more

Type hinting for properties in PHP 7?

January 14, 2023 by Tarik

PHP 7.4 will support typed properties like so: class Person { public string $name; public DateTimeImmutable $dateOfBirth; } PHP 7.3 and earlier do not support this, but there are some alternatives. You can make a private property which is accessible only through getters and setters which have type declarations: class Person { private $name; public … Read more

Getting the User Agent with JavaScript

January 13, 2023 by Tarik

Pure Javascript document.getElementById(‘UserAgent’).value = navigator.userAgent; <input type=”text” id=”UserAgent”> jQuery $(‘#UserAgent’).val(navigator.userAgent); <script src=”https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js”></script> <input type=”text” id=”UserAgent”>

AttributeError: can’t set attribute in python

January 5, 2023 by Tarik

For those searching this error, another thing that can trigger AtributeError: can’t set attribute is if you try to set a decorated @property that has no setter method. Not the problem in the OP’s question, but I’m putting it here to help any searching for the error message directly. (if you don’t like it, go … Read more

JavaScript: Listen for attribute change?

January 4, 2023 by Tarik

You need MutationObserver, Here in snippet I have used setTimeout to simulate modifying attribute var element = document.querySelector(‘#test’); setTimeout(function() { element.setAttribute(‘data-text’, ‘whatever’); }, 5000) var observer = new MutationObserver(function(mutations) { mutations.forEach(function(mutation) { if (mutation.type === “attributes”) { console.log(“attributes changed”) } }); }); observer.observe(element, { attributes: true //configure it to listen to attribute changes }); <div … Read more

How to loop over a Class attributes in Java?

December 31, 2022 by Tarik

There is no linguistic support to do what you’re asking for. You can reflectively access the members of a type at run-time using reflection (e.g. with Class.getDeclaredFields() to get an array of Field), but depending on what you’re trying to do, this may not be the best solution. See also Java Tutorials: Reflection API / … Read more

CSS values using HTML5 data attribute [duplicate]

December 31, 2022 by Tarik

There is, indeed, prevision for such feature, look http://www.w3.org/TR/css3-values/#attr-notation This fiddle should work like what you need, but will not for now. Unfortunately, it’s still a draft, and isn’t fully implemented on major browsers. It does work for content on pseudo-elements, though.