default-value

问题 I currently doing some model transformations using EMF-UML-Implementation. In my model transformation I create an uml class with some attributes. The attributes are type of enumerations I also created. Some of the attribute should get a default value. The default value should be enumeration literals. The question now is, how do I get the enumeration literals to the defaultValue -property of the Property . I already have found that I have to use ValueSpecification . But the UML superstructure

问题 I have a select field that have have present options and I have a php script check a mysql database and add a select tag to the one currently being used. I need to find a way to know if the user have changed the select field or not before submitting it. var Access = document.forms[UIDF]["Access"].value; var DAccess = document.forms[UIDF]["Access"].defaultIndex; <--- This is my problem. I just need to know how to get the selected option value as this keep changing with every user <select name=

问题 Consider example: def decorator(func): def wrapper(*args, **kwargs): print(args, kwargs) func(*args, **kwargs) return wrapper @decorator def foo(x, y, z=0): pass foo(5, 5) Output: (5, 5) {} Why not (5, 5) {'z': 0} ? How to pass all default values of the function foo to *args or **kwargs using only decorator (for functions) or metaclass (for class methods, e.g. __init__ )? 回答1: The wrapper is just a normal function. It does not have "access" to the internals of the wrapped function. You would

问题 I have this right now to use a cookie value if exists otherwise use a default value: $default_carat_min = "0.25"; if($_COOKIE["diamond-search_caratMin"]) { $default_carat_min = $_COOKIE["diamond-search_caratMin"]; } I am going to have to do this with a lot of variables, and its going to get really cluttered/ugly. So I am trying to come up with a cleaner way of writing this. I tried: $default_carat_min = $_COOKIE["diamond-search_caratMin"] | "0.25"; Which did not work. I can do this: $default

问题 I'm having an entity like that: public class Part : Entity { public int Id { get; set; } public string Name { get; set; } public IEnumerable<VersionSection> VersionSections { get { return Sections.Where(s => s is VersionSection).Cast<VersionSection>(); } } public virtual ICollection<Section> Sections { get; set; } public Part() { this.Sections = new List<Section>(); } } I would like to set the default value for the Sections collection very time when I create a new instance of Part following

问题 Thank you for answering my question at Ignore null results in MySQL JOIN queries I've created my own radio station website in localhost, at http://myradiostation.localhost This is the code: <?php $connection = mysql_connect("localhost", "root", "PASSWORD") or die("Error connecting to database"); mysql_select_db("radio1", $connection); $result = mysql_query("SELECT * FROM presenters;", $connection) or die("error querying database"); $i = 0; while($result_ar = mysql_fetch_assoc($result)){ ?>

问题 Below are 4 related posts I could find on Stack Overflow: Validation Error: Value is not valid Validation error value is not valid Jsf : Validation error value is not valid for SelectOneMenu JSF with Enum 'Validation Error: Value is not valid' In these posts, the posters didn't know why they had this error message. In my case, I do know why I have this error, and I would like to change the default "Validation Error: Value is not valid" message to let's say "This is my message" . How could I

问题 As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance. Closed 7 years ago . Why was C++ designed like this?... (This question is different, but intimately related to Not possible: this pointer as a default

问题 We are performing a database migration to SQL Server, and to support a legacy app we have defined views on the SQL Server table which present data as the legacy app expects. However, we're now having trouble with INSTEAD OF INSERT triggers defined on those views, when the fields may have default values. I'll try to give an example. A table in the database has 3 fields, a, b, and c. c is brand new, the legacy app doesn't know about it, so we also have a view with 2 fields, a and b. When the

问题 What's the idiom in Ruby when you want to have a default argument to a function, but one that is dependent on another parameter / another variable? For example, in Python, an example is: def insort_right(a, x, lo=0, hi=None): if hi is None: hi = len(a) while lo < hi: mid = (lo+hi)//2 if x < a[mid]: hi = mid else: lo = mid+1 a.insert(lo, x) Here, if hi is not supplied, it should be len(a) . You can't do len(a) in the default argument list, so you assign it a sentinel value, None, and check for