methods

问题 If I have a list of items, and for every one of them I'm calling an instance method, how can I save the value of the method and prevent it from being calculated every time it's called? Say I have two items: <% if method_true %> do something <% end %> <% if method_true %> do something else <% end %> If method_true == true, how can I just pass the value true through the two ifs instead of calculating it every time? 回答1: I'm sure there's a more sophisticated answer out there, but for my app I

问题 I use this line of code in an app with XCode 10 in order to dim the home indicator on iPhone X and associated edgeless apple devices. override func prefersHomeIndicatorAutoHidden() -> Bool { return true } Now the funny thing is, I have an exact copy of this app and on one copy the code works, whilst on the over the code does not compile: Method does not override any method from its superclass Indeed when I start typing "prefers..." , prefersHomeIndicatorAutoHidden appears as a read-only

问题 I'm allowing my users to have multiple profiles (user has many profiles) and one of them is the default. In my users table I have a default_profile_id. How do I create a "default_profile" like Devise's current_user which I can use everywhere? Where should I put this line? default_profile = Profile.find(current_user.default_profile_id) 回答1: Devise's current_user method looks like this: def current_#{mapping} @current_#{mapping} ||= warden.authenticate(:scope => :#{mapping}) end As you can see,

问题 I want to sort members by name in the source code. Is there any easy way to do it? I'm using NetBeans, but if there is another editor that can do that, just tell me the name of it. 回答1: In Netbeans 8.0.1: Tools -> Options -> Editor -> Formatting -> Category: Ordering Then: Source -> Organize Members 回答2: Eclipse can do it. 回答3: This is implemented in Netbeans 7.3: http://netbeans.org/bugzilla/show_bug.cgi?id=212528 回答4: As @PaulCroarkin said - use eclipse, Or you can use Jalopy as part of

问题 I want to sort members by name in the source code. Is there any easy way to do it? I'm using NetBeans, but if there is another editor that can do that, just tell me the name of it. 回答1: In Netbeans 8.0.1: Tools -> Options -> Editor -> Formatting -> Category: Ordering Then: Source -> Organize Members 回答2: Eclipse can do it. 回答3: This is implemented in Netbeans 7.3: http://netbeans.org/bugzilla/show_bug.cgi?id=212528 回答4: As @PaulCroarkin said - use eclipse, Or you can use Jalopy as part of

问题 What is the use of mongoose methods and statics and how are they different from normal functions? Can anyone explain the difference with example. 回答1: Database logic should be encapsulated within the data model. Mongoose provides 2 ways of doing this, methods and statics. Methods adds an instance method to documents whereas Statics adds static "class" methods to the Models itself. Given the example Animal Model below: var AnimalSchema = mongoose.Schema({ name: String, type: String, hasTail:

问题 What is the use of mongoose methods and statics and how are they different from normal functions? Can anyone explain the difference with example. 回答1: Database logic should be encapsulated within the data model. Mongoose provides 2 ways of doing this, methods and statics. Methods adds an instance method to documents whereas Statics adds static "class" methods to the Models itself. Given the example Animal Model below: var AnimalSchema = mongoose.Schema({ name: String, type: String, hasTail:

问题 In ListView, I can easily use def post(self, request) method to make a post request from a list view. But I want to make the post request from def get_queryset(self) which I am not yet able to do. When I try to do it it shows " method 405 not allowed! " even though post method is allowed through http_method_names . How can I access POST request inside get_queryset function? class ZonListView(SearchMixin, SingleTableMixin, ListView): template_name = 'cadmin/list.html' model = Zon table_class =

问题 I want to do the following: pattern = cl().a().b("test").c() where cl is a class and a, b, c are class methods. After that I need to call pattern.to_string and it should output a string that was formed. Each method returns a string. Now how can I achieve the above? Append the method output to a list? What about the chainable function? If I wrote the class the normal way, the above won't work. Thank. 回答1: Return the class instance at the end of each method and store the intermediate results in

问题 I have a class with an __init__ method where I define some variables, as well as a method AddSignalSpectrum : class SpectrumGraph: # Properties def __init__(self): self.PlotHeight= 300 self.PlotWidth = 800 self.xRangeMin = -10 self.xRangeMax = 10 self.yRangeMin = -0.1*(self.xRangeMax - self.xRangeMin) self.yRangeMax = 0.9*(self.xRangeMax -self.xRangeMin) def AddSignalSpectrum( self, name, Type, CenterPosition, Bandwidth=2, Height = self.yRangeMax*0.8, Color = "#0000FF", LineWidth = 2,