Search Results

Search found 53100 results on 2124 pages for 'web design'.

Page 561/2124 | < Previous Page | 557 558 559 560 561 562 563 564 565 566 567 568  | Next Page >

  • Sharing class member data between sub components

    - by Tim Gradwell
    I have an aggregate 'main' class which contains some data which I wish to share. The main class also has other class members. I want to share the data with these other class members. What is the correct / neatest way to do this? The specific example I have is as follows. The main class is a .net Form. I have some controls (actually controls within controls) on the main form which need access to the shared data. Main Form - DataX - DataY - Control1 -- Subcontrol1 - Control2 -- SubControl2 SubControls 1 and 2 both wish to access DataX and DataY. The trouble is, I feel like better practice (to reduce coupling), would be that either subcontrols should not know about Main Form, or Main Form should not know about subcontrols - probably the former. For subcontrols not to know about Main Form, would probably mean Main Form passing references to both Controls 1 and 2, which in turn would pass the references on to SubControls 1 and 2. Lots of lines of code which just forward the references. If I later added DataZ and DataW, and Controls 3 and 4 and SubControls 3 and 4, I'd have to add lots more reference forwarding code. It seems simpler to me to give SubControls 1 and 2 member references to Main Form. That way, any sub control could just ask for MainForm.DataX or MainForm.DataY and if I ever added new data, I could just access it directly from the sub controls with no hassle. But it still involves setting the 'MainForm' member references every time I add a new Control or Subcontrol. And it gives me a gut feeling of 'wrong'. As you might be able to tell I'm not happy with either of my solutions. Is there a better way? Thanks

    Read the article

  • How to set a value from another class

    - by Ram
    Its said that property should not be "Set" only and it should be "Get" as well. What should i do if I need to set value to a variable from some other class? The will keep changing so I cannot pass it through constructor. Shall I create a function for this as shown below? class A { public void SetValue() { b = new B(); b.SetTest(10); } } class B { int test; public void SetTest(int value) { test = value; } } What are the other alternatives?

    Read the article

  • One database or many?

    - by dsims
    I am developing a website that will manage data for multiple entities. No data is shared between entities, but they may be owned by the same customer. A customer may want to manage all their entities from a single "dashboard". So should I have one database for everything, or keep the data seperated into individual databases? Is there a best-practice? What are the positives/negatives for having a: database for the entire site (entity has a "customerID", data has "entityID") database for each customer (data has "entityID") database for each entity (relation of database to customer is outside of database) Multiple databases seems like it would have better performance (fewer rows and joins) but may eventually become a maintenance nightmare.

    Read the article

  • How to map one class against multiple tables with SQLAlchemy?

    - by tote
    Lets say that I have a database structure with three tables that look like this: items - item_id - item_handle attributes - attribute_id - attribute_name item_attributes - item_attribute_id - item_id - attribute_id - attribute_value I would like to be able to do this in SQLAlchemy: item = Item('item1') item.foo = 'bar' session.add(item) session.commit() item1 = session.query(Item).filter_by(handle='item1').one() print item1.foo # => 'bar' I'm new to SQLAlchemy and I found this in the documentation (http://www.sqlalchemy.org/docs/05/mappers.html#mapping-a-class-against-multiple-tables): j = join(items, item_attributes, items.c.item_id == item_attributes.c.item_id). \ join(attributes, item_attributes.c.attribute_id == attributes.c.attribute_id) mapper(Item, j, properties={ 'item_id': [items.c.item_id, item_attributes.c.item_id], 'attribute_id': [item_attributes.c.attribute_id, attributes.c.attribute_id], }) It only adds item_id and attribute_id to Item and its not possible to add attributes to Item object. Is what I'm trying to achieve possible with SQLAlchemy? Is there a better way to structure the database to get the same behaviour of "dynamic columns"?

    Read the article

  • DDD and avoiding CRUD

    - by g_b
    It seems that on most articles I read, CRUD is to be avoided in DDD as we are dealing with modeling business process and not data. However, I find it hard to see not to have CRUD operations on certain entities. For example, in a school grading system, before teachers can grade students, a SchoolYear has to be present or perhaps a GradingPeriod. I can't see how we can manage GradingPeriods without CRUD. Could someone enlighten me on this?

    Read the article

  • Constructors + Dependency Injection

    - by Sunny
    If I am writing up a class with more than 1 constructor parameter like: class A{ public A(Dependency1 d1, Dependency2 d2, ...){} } I usually create a "argument holder"-type of class like: class AArgs{ public Dependency1 d1 { get; private set; } public Dependency2 d2 { get; private set; } ... } and then: class A{ public A(AArgs args){} } Typically, using a DI-container I can configure the constructor for dependencies & resolve them & so there is minimum impact when the constructors need to change. Is this considered an anti-pattern and/or any arguments against doing this?

    Read the article

  • Interpreted languages: The higher-level the faster?

    - by immersion
    I have designed around 5 experimental languages and interpreters for them so far, for education, as a hobby and for fun. One thing I noticed: The assembly-like language featuring only subroutines and conditional jumps as structures was much slower than the high-level language featuring if, while and so on. I developed them both simultaneously and both were interpreted languages. I wrote the interpreters in C++ and I tried to optimize the code-execution part to be as fast as possible. My hypothesis: In almost all cases, performance of interpreted languages rises with their level (high/low). Am I basically right with this? (If not, why?)

    Read the article

  • java class that simulates a simple database table

    - by ericso
    I have a collection of heterogenous data that I pull from a database table mtable. Then, for every unique value uv in column A, I compute a function of (SELECT * FROM mtable WHERE A=uv). Then I do the same for column B, and column C. There are rather a lot of unique values, so I don't want to hit the db repeatedly - I would rather have a class that replicates some of the functionality (most importantly some version of SELECT WHERE). Additionally, I would like to abstract the column names away from the class definition, if that makes any sense - the constructor should take a list of names as a parameter, and also, I suppose, a list of types (right now this is just a String[], which seems hacky). I'm getting the initial data from a RowSet. I've more or less done this by using a hashmap that maps Strings to lists/arrays of Objects, but I keep getting bogged down in comparisons and types, and am thinking that my current implementation really isn't as clean and clear as it could be. I'm pretty new to java, also, and am not sure if I'm not going down a completely incorrect path. Does anyone have any suggestions?

    Read the article

  • Class with proprties that haven't been set

    - by koumides
    Hello there, I am creating a class in C# which eventually will be part of a library that other uses can use. A user of this class has to set some properties and then use a public method to retrieve the results. What shall I do when a user calls the method without setting all the properties? Throw exception and expect the user to catch it? Thanks

    Read the article

  • C++: Conceptual problem in designing an intepreter

    - by sub
    I'm programming an interpreter for an experimental programming language (educational, fun,...) So far, everything went well (Tokenizer & Parser), but I'm getting a huge problem with some of the data structures in the part that actually runs the tokenized and parsed code. My programming language basically has only two types, int and string, and they are represented as C++ strings (std class) and ints Here is a short version of the data structure that I use to pass values around: enum DataType { Null, Int, String } class Symbol { public: string identifier; DataType type; string stringValue; int intValue; } I can't use union because string doesn't allow me to. This structure above is beginning to give me a headache. I have to scatter code like this everywhere in order to make it work, it is beginning to grow unmaintainable: if( mySymbol.type == Int ) { mySymbol.intValue = 1234; } else { mySymbol.stringValue = "abcde"; } I use the Symbol data structure for variables, return values for functions and general representation of values in the programming language. Is there any better way to solve this? I hope so!

    Read the article

  • is Payment table needed when you have an invoice table like this?

    - by EBAGHAKI
    this is my invoice table: Invoice Table: invoice_id creation_date due_date payment_date status enum('not paid','paid','expired') user_id total_price I wonder if it's Useful to have a payment table in order to record user payments for invoices. payment table can be like this: payment_id payment_date invoice_id price_paid status enum('successful', 'not successful')

    Read the article

  • Handling missing data

    - by soppotare
    Say I have a simple helpdesk application which logs calls made by users. I would typically have such fields in a table relating to the call e.g. CallID, Description, CustomerID etc. I Would also have a table of customers including CustomerID, Username, Password, FullName etc. Now when a user is deleted from the customers table then the inner join between the calls table and the users table to find out historically which user logged a call would produce no results. How do people usually deal with this? Have seperate customer and useraccount tables Just disable the accounts so the data is still available Record the customers name in the calls table as a seperate field. or any other methods / suggestions?

    Read the article

  • Splitting values into groups evenly

    - by Paul Knopf
    Let me try to explain the situation the best I can. Lets say I have 3 values 1, 2, 3 I tell an algorithm to split this values into x columns. Lets say x = 2 for clarification. The algorithm determines that the group of values is best put into two columns the following way. 1st column 2nd column --------------------------- 1 3 2 Each column has an even number (totals, not literals) value. Now lets say I have the following values 7, 8, 3, 1, 4 I tell the algorithm that I want the values split into 3 columns. The algorithm now tells me that the following is the best fit. 1st column 2nd column 3rd column 8 7 3 1 4 Notice how the columns arent quiet even, but it is as close as it can get. A little over and a little under is considered ok, as long as the list is AS CLOSE TO EVEN AS IT CAN BE. Anybody got any suggestions? Know any good methods of doing this?

    Read the article

  • Where do you find images and graphics for your softwares ?

    - by ereOn
    Hi, As a programmer, I'm sure some of you already experienced the same problem: You create a good software (free, open-source, or for friend-only diffusion, whatever) relying on good code and good ideas but since you're a programmer and not an image designer, your program looks just bad. While it seems pretty easy to find motivated developpers to join for free an open-source project, it seems quite hard to find a single free graphic designer. What free and good resources do you usually use for your programs/websites ? Do you have any cool tip that you're willing to share ?

    Read the article

  • Singletons and constants

    - by devoured elysium
    I am making a program which makes use of a couple of constants. At first, each time I needed to use a constant, I'd define it as //C# private static readonly int MyConstant = xxx; //Java private static final int MyConstant = xxx; in the class where I'd need it. After some time, I started to realise that some constants would be needed in more than one class. At this time, I had 3 choises: To define them in the different classes that needed it. This leads to repetition. If by some reason later I need to change one of them, I'd have to check in all classes to replace them everywhere. To define a static class/singleton with all the constants as public. If I needed a constant X in ClassA, ClassB and ClassC, I could just define it in ClassA as public, and then have ClassB and ClassC refer to them. This solution doesn't seem that good to me as it introduces even more dependencies as the classes already have between them. I ended up implementing my code with the second option. Is that the best alternative? I feel I am probably missing some other better alternative. What worries me about using the singleton here is that it is nowhere clear to a user of the class that this class is using the singleton. Maybe I could create a ConstantsClass that held all the constants needed and then I'd pass it in the constructor to the classes that'd need it? Thanks

    Read the article

  • Which controls are being used?

    - by Jack
    Are there any tools available that allow you to 'look' at any given application and show you which WinForm controls are being used in that application? I happen to have an app which I like the GUI of, and I want to use a similar structure in my own app. Instead of developing these controls myself, it may be easier to buy them, if only I can spot which are being used... Any suggestions?

    Read the article

  • Good JDBC pattern

    - by Java Developer
    What is the good practice for database operation in Java application? Do you construct the DML syntax in the Java code and send the statements to DB engine for execution, or you just collect the parameters and then make a call to stored procedure with the parameters via java code? or neither because that's just not how to do it? can anyone give an example of a full database utility classes to do database operations in Java app? also what about the transaction manager? My assignment is to make database operation that is modular in Java. Thanks

    Read the article

< Previous Page | 557 558 559 560 561 562 563 564 565 566 567 568  | Next Page >