readonly

Why Tuple's items are ReadOnly?

由 不想你离开。 提交于 2019-11-27 04:34:56
I was thinking to use Tuple class to store 2 integer information (StartAddress, EndAddress) I need in my program. But I discover that Tuple items are ReadOnly, so if I need to set a value for an item, I need to re-instantiate a Tuple. What is the reason behind this design decision? Tuples originated in functional programming . In (purely) functional programming, everything is immutable by design - a certain variable only has a single definition at all times, as in mathematics. The .NET designers wisely followed the same principle when integrating the functional style into C#/.NET, despite it

Whole model as read-only

由 こ雲淡風輕ζ 提交于 2019-11-27 04:33:43
问题 Is there a way to make a model read-only in the django admin? but I mean the whole model. So, no adding, no deleting, no changing, just see the objects and the fields, everything as read-only? 回答1: ModelAdmin provides the hook get_readonly_fields() - the following is untested, my idea being to determine all fields the way ModelAdmin does it, without running into a recursion with the readonly fields themselves: from django.contrib.admin.util import flatten_fieldsets class ReadOnlyAdmin

When, if ever, should we use const?

由 主宰稳场 提交于 2019-11-27 04:29:26
问题 Const is baked into the client code. Readonly isn't. But const is faster. May be only slightly though. The question is, is there ever any scenario where you should prefer const over readonly ? Or to rephrase, are we not practically always better off using a readonly instead of a const (keeping in mind the above-said baking thing)? 回答1: I believe the only time "const" is appropriate is when there is a spec that you're coding against that is more durable than the program you're writing. For

Why does a read-only textbox not return any data in ASP.NET?

由 徘徊边缘 提交于 2019-11-27 03:08:47
问题 I've set a textbox to read-only. When the user clicks on it, a calendar is displayed and the user selects the date which inputs into the read-only textbox. But when I try to enter the data into the database, it shows null value. What is wrong? 回答1: There is a little bit of strangeness when it comes to the ASP.NET Readonly property and the readonly attribute of an HTML input element. Rather than setting the Readonly property of the web control try simply adding the HTML attribute to the

How to implement a read-only member variable in PHP?

由 橙三吉。 提交于 2019-11-27 02:49:50
问题 When trying to change it,throw an exception. 回答1: I suppose a solution, for class properties, would be to : not define a property with the name that interests you use the magic __get method to access that property, using the "fake" name define the __set method so it throws an exception when trying to set that property. See Overloading, for more informations on magic methods. For variables, I don't think it's possible to have a read-only variable for which PHP will throw an exception when you

How can you make a variable/Object read only in Javascript? [duplicate]

由 混江龙づ霸主 提交于 2019-11-27 01:30:47
问题 Possible Duplicate: Can Read-Only Properties be Implemented in Pure JavaScript? I have an Object that I only want to be defined when constructed. How can I prevent the Object reference from being changed? 回答1: Realistically... by not overwriting it. You could always control access by wrapping it in an object that only offers GetObj with no SetObj, but of course, the wrapper is equally liable to overwriting, as are its "private" member properties that would be "hidden" via the GetObj method.

ActiveRecord::ReadOnlyRecord when using ActiveAdmin and Friendly_id

由 北城余情 提交于 2019-11-27 01:22:06
问题 I started using ActiveAdmin recently in a project and almost everything works great but I'm having a problem when using it in combination with the friendly_id gem. I'm getting ActiveRecord::ReadOnlyRecord thrown for my forms [i believe] because of the friendly_id attribute whose ID is readonly: {"utf8"=>"✓", "_method"=>"put", "authenticity_token"=>"Rc5PmUYZt3BiLvfPQr8iCPPXlbfgjoe/n+NhCwXazNs=", "space"=>{"name"=>"The Kosmonaut", "address"=>"8 Sichovykh Striltsiv 24", "email"=>"info

WCF: Exposing readonly DataMember properties without set?

由 拈花ヽ惹草 提交于 2019-11-27 00:36:16
I have a server side class which I make available on the client side through a [DataContract]. This class has a readonly field which I'd like to make available through a property. However, I'm unable to do so because it doesn't seem that I'm allowed to add a [DataMember] property without having both get and set. So - is there a way to have a [DataMember] property without setter? [DataContract] class SomeClass { private readonly int _id; public SomeClass() { .. } [DataMember] public int Id { get { return _id; } } [DataMember] public string SomeString { get; set; } } Or will the solution be use

Github: readonly access to a private repo

由 假装没事ソ 提交于 2019-11-27 00:19:23
问题 I am developing some private projects on Github, and I would like to add nightly cronjobs to my deployments servers to pull the latest version from github. I am currently doing this by generating keypairs on every deployment server and adding the public key to the github project as 'Deployment key'. However, I recently found out that these deployment keys actually do have write access to the project. Hence, every of the server administrators could potentially start editing. Furthermore I can

Why can't radio buttons be “readonly”?

由 和自甴很熟 提交于 2019-11-26 23:33:35
I would like to show a radio button, have its value submitted, but depending on the circumstances, have it not editable. Disabled doesn't work, because it doesn't submit the value (or does it?), and it grays out the radio button. Read-only is really what I'm looking for, but for some mysterious reason it doesn't work. Is there some weird trick I need to pull to get read-only to work as expected? Should I just do it in JavaScript instead? Incidentally, does anyone know why read-only doesn't work in radio buttons, while it does work in other input tags? Is this one of those incomprehensible
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