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  • help me refactor iteration over a generic collection

    - by Biswanath
    Hi, I am working with a generic data structure, say MyGeneric<Type>. There is a case where I have to iterate over all the values it holds The code I am trying to do. for ( all the keys in myGeneric ) { // do lot of stuff here } Now the generic can hold base type as double and string and it can hold some user-defined type also. There is a particular situation where I have to some specific work depending upon the type of the generic. so the final code block looks something like this for( all the keys in myGeneric ) { if key is type foo then //do foo foo else if key is of type bar //do bar bar } Now, as complexity sensitive as I am I do not like to have an if condition in the for loop. So the next solution I did was if myGeneric is of type foo call fooIterator(myGeneric) if myGenric is of type bar call barItetrator(myGeneric) function FooIterator() { // ..... // foo work //...... } function BarItetrator() { // ..... // bar work //...... } Then again when somebody sees my code then I am quite sure that they will shout where is the "refactoring". What is the ideal thing to do in this situation ? Thanks.

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  • I want to prevent ASP.NET GridView from reacting to the enter button

    - by StephaneT
    I have an ASP.NET page with a gridview control on it with a CommandButton column with delete and select commands active. Pressing the enter key causes the first command button in the gridview to fire, which deletes a row. I don't want this to happen. Can I change the gridview control in a way that it does not react anymore to pressing the enter key? There is a textbox and button on the screen as well. They don't need to be responsive to hitting enter, but you must be able to fill in the textbox. Currently we popup a confirmation dialog to prevent accidental deletes, but we need something better than this. This is the markup for the gridview, as you can see it's inside an asp.net updatepanel (i forgot to mention that, sorry): (I left out most columns and the formatting) <asp:UpdatePanel ID="upContent" runat="server" UpdateMode="Conditional"> <Triggers> <asp:AsyncPostBackTrigger ControlID="btnFilter" /> <asp:AsyncPostBackTrigger ControlID="btnEdit" EventName="Click" /> </Triggers> <ContentTemplate> <div id="CodeGrid" class="Grid"> <asp:GridView ID="dgCode" runat="server"> <Columns> <asp:CommandField SelectImageUrl="~/Images/Select.GIF" ShowSelectButton="True" ButtonType="Image" CancelText="" EditText="" InsertText="" NewText="" UpdateText="" DeleteImageUrl="~/Images/Delete.GIF" ShowDeleteButton="True" /> <asp:BoundField DataField="Id" HeaderText="ID" Visible="False" /> </Columns> </asp:GridView> </div> </ContentTemplate> </asp:UpdatePanel>

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  • When do Symfony's user attributes get written to session?

    - by Rob Wilkerson
    I have a Symfony app that populates the "widgets" of a portal application and I'm noticing something (that seems) odd. The portal app has iframes that make calls to the Symfony app. On each of those calls, a random user key is passed on the query string. The Symfony app stores that key its session using myUser->setAttribute(). If the incoming value is different from what it has in session, it overwrites the session value. In pseudo-code (and applying a synchronous nature for clarity even though it may not exist): # Widget request arrives with ?foo=bar if the user attribute 'foo' does not equal 'bar' overwrite the user attribute 'foo' with 'bar' end What I'm noticing is that, on a portal page with multiple widgets (read: multiple requests coming in more or less simultaneously) where the value needs to be overwritten, each request is trying to overwrite. Is this a timing problem? When I look at the log prints, I'd expect the first request that arrives to overwrite and subsequent requests to see that the user attribute they received matches what was just put into cache by the initial request. In this scenario, it could be that subsequent requests begin (and are checked) even before the first one--the one that should overwrite the cached value--has completely finished. Are session values not really available to subsequent requests until one request has completed entirely or could there be something else that I'm missing? Thanks.

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  • Java : Inner class of an interface (from google guice)

    - by bsreekanth
    Hello, I was going through the source of google guice, and found an unfamiliar piece of code. It would be great learning if someone can clarify it. I have very basic understanding of inner classes, as they keep the implementation details close to the public interface. Otherwise the inner class may pollute the namespace. Now, I see the below lines at public static final Scope SINGLETON = new Scope() { public <T> Provider<T> scope(final Key<T> key, final Provider<T> creator) { return new Provider<T>() { ......... } It assign an inner class instance to the static variable, but Scope is an interface defined as (at) public interface Scope Is it possible to instantiate the interface?? or is it a succinct syntax for an anonymous implementation of an interface?? If anyone can explain what the author is intended by multiple nested classes above (Scope and Provider), and why it make sense to implement this way, it would help me to understand. thanks.

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  • Bandwidth Monitoring in asp.net

    - by asifch
    HI, We are developing a multi-tenant application in Asp.Net with separate DB for each tenant, in which one of the requirement is to monitor the bandwidth usage for each tenant, i have tried to search but not found much help on the topic,we want to monitor exactly how much bandwidth is being used for each tenant while each tenant can have its own top level domain or a sub domain or a combination of both. so what are the available options, the ones which i can think of can be 1. IIS Log Monitoring means a separate application which will calculate the bandwidth for each tenant. 2. Log Each Request and Response for a tenant from within the application and then calculate the total bandwidth usage based on that. 3. Use some third part components if available So what do you think will be the best approach, also if there is any other way to do this.

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  • Is there a class like a Dictionary without a Value template? Is HashSet<T> the correct answer?

    - by myotherme
    I have 3 tables: Foos, Bars and FooBarConfirmations I want to have a in-memory list of FooBarConfirmations by their hash: FooID BarID Hash 1 1 1_1 2 1 2_1 1 2 1_2 2 2 2_2 What would be the best Class to use to store this type of structure in-memory, so that I can quickly check to see if a combination exists like so: list.Contains("1_2"); I can do this with Dictionary<string,anything>, but it "feels" wrong. HashSet looks like the right tool for the job, but does it use some form of hashing algorithm in the background to do the lookups efficiently?

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  • Unable to delete inherited entity class in EF4

    - by Coding Gorilla
    I have two entities in an EF4 model (using Model First), let's call them EntityA and EntityB. EntityA is marked as abstract, and EntityB inherits from EntityA. They are similar to the following: public class EntityA { public Guid Id; public string Name; public string Uri; } public class EntityB : EntityA { public string AnotherProperty; } The generated database tables look as I would expect them, with EntityA as on table, and then another table like: EntityA_EntityB Id (PK, FK, uniqueidentifier) AnotherProperty (varchar) There is a foreign key constraint on EntityA_EntityB that references EntityA's Id property, no cascades are configured (although I did try changing these myself). The problem is that when I attempt to do something like: Context.DeleteObject(EntityA_EntityB); EF attempts to delete the EntityA_EntityB table record before deleting the EntityA table record, which of course violates the foreign key constraint on EntityA_EntityB table. Using EFProfiler I see the following commands being sent to the database: delete [dbo].[EntityA_EntityB] where (([Id] = '5c02899f-09ea-2ed9-d44b-01aef80f6b64' /* @0 */) followed by delete [dbo].[EntityA] where ([Id] = '5c02899f-09ea-2ed9-d44b-01aef80f6b64' /* @0 */) I'm completely stumped as to how to get around this problem. I would think the EF should know that it needs to delete the base class first, before deleting the inherited class. I know I could do some triggers or other database type solutions, but I'd rather avoid doing that if I can. All my classes are POCO built using some customized T4 templates. I don't want to paste in a lot of extraneous code, but if you need more information I'll provide what I can.

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  • HELP! need to make a VoIP program for WiMAX in NS-2 work..

    - by janiemack
    I've been trying to get this working for the past 2 days and i'm completely stuck. I'm trying to make a simple VoIP program work in the NIST module for WiMAX http ://community.4gdeveloper.com/attachments/download/14/090720150504_ns2-Release-2.6.tar.gz version 2.6 , using NS-2.31 (remove space btw 'p' and ':' ) http ://downloads.sourceforge.net/nsnam/ns-allinone-2.31.tar.gz?modtime=1173548159&big_mirror=0 (remove space btw 'p' and ':' ) The installation process goes fine. When i run this program, I'm getting an error saying " OFDMAPhy : error did not find match for permutation and bw combination" Some help would be really appreciated. thanks!

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  • what are your biggest complaints about TFS as source-control?

    - by jcollum
    I've used TFS for about 18 months now and I'm really not excited about it. It seems like the worst of the current versions of SCMs on the market. I think this thread will help people decide if TFS is for them vs. other source control systems. While TFS does a lot more than that, I think that source control is so critical to software development that any system (or combination thereof) that you pick needs to consider source control first. So, feel free to sound off. Maybe it'll make us feel better and be informative at the same time.

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  • Connection string problems on shared hosting with sql server 2005 express

    - by dagogo
    hi i have problem connecting to my db on a shared hosting, my host provider says they deployed sql 2005 express on their database and i prepared my connection string as follows to take advantage of sql express. \ the data source nae i used originally was ./SQLExpress but my host provider asked that i change it to local host, although with the former it didnt connect, but still with the change as indicated above the error still comes up on access to my default page. the error is as follows; Server Error in '/' Application. Invalid value for key 'attachdbfilename'. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.ArgumentException: Invalid value for key 'attachdbfilename'. Source Error: Line 120: Public Function GetID(ByVal sLgaName As String) As Integer Line 121: Dim q As String = "Select PLID " & "From LGA " & "Where LGAName = " & "'" & sLgaName & "'" Line 122: Dim cn As New SqlConnection(Me.ConnectionString) Line 123: Dim cmd As New SqlCommand(q, cn) Line 124: ive read up a lot on the web and googled ma fingers numb on this, i have a deadline to deliver this project and having successfully built the app it frustrating for this to happen. pls help me.

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  • From .NET TO SQL

    - by Berlioz
    How do you pass a value from your DAL to your sproc so that the ISNULL function will do it's job. Particularly the DATE value coming from my .NET assembly. In T-SQL an INSERT STMNT and in the VALUES clause, the line of interest goes like this; ISNULL(@myparm_forcolumn9, @myparm_forcolumn9). What value do I pass from .NET to make this line in my sproc work universally, so I don't have to write a millions INSERT SPROCS for every combination of columns??? I just want to write one stored procedure(sproc) that will handle all INSERTS in my universe.

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  • Stacking standard output of `su`

    - by Kristopher Ives
    I've got some code that I wrote that uses a combination of bash and PHP command line scripting. The script is ran as root and then uses su to become various uses. I start a session like this: $result = `su SomeUser ./dothis.php` Here ./dothis.php is a script that may generate some output being stored in $result, but the problem is that there is usually output that doesn't get caught and makes it hard for me to read my script output. How can I make sure that the output is being captured within this su stacking?

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  • if exists, update, else insert new record

    - by I__
    i am inserting values into a table if the record exists already replace it, and if it does not exist then add a new one. so far i have this code: INSERT INTO table_name VALUES (value1, value2, value3,...) where pk="some_id"; but i need something like this if not pk="some_id" exists then INSERT INTO table_name VALUES (value1, value2, value3,...) where pk="some_id"; else update table_name where pk="some_id" what would be the correct SQL syntax for this? please note that i am using sql access and that i guess it can be a combination of vba and sql

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  • saveall not saving associated data

    - by junior29101
    I'm having a problem trying to save (update) some associated data. I've read about a million google returns, but nothing seems to be the solution. I'm at my wit's end and hope some kind soul here can help. I'm using 1.3.0-RC4, my database is in InnoDB. Course has many course_tees CourseTee belongs to course My controller function is pretty simple (I've made it as simple as possible): if(!empty($this-data)) $this-Course-saveAll($this-data); I've tried a lot of different variations of that $this-data['Course'], save($this-data), etc without luck. It saves the Course info, but not the CourseTee stuff. I don't get an error message. Since I don't know how many tees any given course will have, I generate the form inputs dynamically in a loop. $form-input('CourseTee.'.$i.'.teeName', array('error' = false, 'label' = false, 'value'=$data['course_tees'][$i]['teeName'])) The course inputs are simpler: $form-input('Course.hcp'.$j, array('error' = false, 'label' = false, 'class' = 'form_small_w', 'value'=$data['Course']['hcp'.$j])) And this is how my data is formatted: Array ( [Course] = Array ( [id] = 1028476 ... ) [CourseTee] = Array ( [0] = Array ( [key] = 636 [courseid] = 1028476 ... ) [1] = Array ( [key] = 637 [courseid] = 1028476 ... ) ... ) )

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  • Dollar sign and/or Dash breaking Razor's parser

    - by justSteve
    the end-result i'm trying to render: <input type="radio" name="options" id="options_1" />$1 - A Not Very Expensive Chocolate <input type="radio" name="options" id="options_2" />$10 - A Kinda Expensive Chocolate <input type="radio" name="options" id="options_3" />$100 - A Really Expensive Chocolate From this code: @foreach (var o in Model.Options){ <input type="radio" name="options" id=@("options_" + @o.ID) />[email protected] - @o.Label } If i drop both the '$' and the '-' from what should be plain old text - stuff works. Adding either resulted in compiler warnings and runtime errors. I've tried the explicit syntax as described here but haven't found the right combination yet.

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  • Has anyone ever successfully make index merge work for MySQL?

    - by user198729
    Setup: mysql> create table t(a integer unsigned,b integer unsigned); mysql> insert into t(a,b) values (1,2),(1,3),(2,4); mysql> create index i_t_a on t(a); mysql> create index i_t_b on t(b); mysql> explain select * from t where a=1 or b=4; +----+-------------+-------+------+---------------+------+---------+------+------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+------+---------------+------+---------+------+------+-------------+ | 1 | SIMPLE | t | ALL | i_t_a,i_t_b | NULL | NULL | NULL | 3 | Using where | +----+-------------+-------+------+---------------+------+---------+------+------+-------------+ Is there something I'm missing? Update mysql> explain select * from t where a=1 or b=4; +----+-------------+-------+------+---------------+------+---------+------+------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+------+---------------+------+---------+------+------+-------------+ | 1 | SIMPLE | t | ALL | i_t_a,i_t_b | NULL | NULL | NULL | 1863 | Using where | +----+-------------+-------+------+---------------+------+---------+------+------+-------------+ Version: mysql> select version(); +----------------------+ | version() | +----------------------+ | 5.1.36-community-log | +----------------------+ Has anyone ever successfully make index merge work for MySQL? I'll be glad to see successful stories here:)

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  • Is it possible to have a mysql table accept a null value for a primary_key column referencing a diff

    - by Dr.Dredel
    I have a table that has a column which holds the id of a row in another table. However, when table A is being populated, table B may or may not have a row ready for table A. My question is, is it possible to have mysql prevent an invalid value from being entered but be ok with a NULL? or does a foreign key necessitate a valid related value? So... what I'm looking for (in pseudo code) is this: Table "person" id | name Table "people" id | group_name | person_id (foreign key id from table person) insert into person (1, 'joe'); insert into people (1, 'foo', 1)//kosher insert into people (1, 'foo', NULL)//also kosher insert into people(1, 'foo', 7)// should fail since there is no id 7 in the person table. The reason I need this is that I'm having a chicken and egg issue where it makes perfect sense for the rows in the people table to be created before hand (in this example, I'm creating the groups and would like them to pre-exist the people who join them). And I realize that THIS example is silly and I would just put the group id in the person table rather than vice-versa, but in my real-world problem that is not workable. Just curious if I need to allow any and all values in order to make this work, or if there's some way to allow for null.

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  • Trouble swapping values as keys in generic java BST class

    - by user1729869
    I was given a generic binary search tree class with the following declaration: public class BST<K extends Comparable<K>, V> I was asked to write a method that reverses the BST such that the values become the keys and keys become values. When I call the following method (defined in the class given) reverseDict.put(originalDict.get(key), key); I get the following two error messages from Netbeans: Exception in thread "main" java.lang.RuntimeException: Uncompilable source code - Erroneous sym type: BST.put And also: no suitable method found for put(V,K) method BST.put(BST<K,V>.Node,K,V) is not applicable (actual and formal argument lists differ in length) method BST.put(K,V) is not applicable (actual argument V cannot be converted to K by method invocation conversion) where V,K are type-variables: V extends Object declared in method <K,V>reverseBST(BST<K,V>) K extends Comparable<K> declared in method <K,V>reverseBST(BST<K,V>) From what the error messages are telling me, since my values do not extend Comparable I am unable to use them as keys. If I am right, how can I get around that without changing the class given (maybe a cast)?

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  • how to find missing rows in oracle

    - by user203212
    Hi, I have a table called 2 tables create table ORDERS ( ORDER_NO NUMBER(38,0) not null, ORDER_DATE DATE not null, SHIP_DATE DATE null, SHIPPING_METHOD VARCHAR2(12) null, TAX_STATUS CHAR(1) null, SUBTOTAL NUMBER null, TAX_AMT NUMBER null, SHIPPING_CHARGE NUMBER null, TOTAL_AMT NUMBER null, CUSTOMER_NO NUMBER(38,0) null, EMPLOYEE_NO NUMBER(38,0) null, BRANCH_NO NUMBER(38,0) null, constraint ORDERS_ORDERNO_PK primary key (ORDER_NO) ); and create table PAYMENTS ( PAYMENT_NO NUMBER(38,0) NOT NULL, CUSTOMER_NO NUMBER(38,0) null, ORDER_NO NUMBER(38,0) null, AMT_PAID NUMBER NULL, PAY_METHOD VARCHAR(10) NULL, DATE_PAID DATE NULL, LATE_DAYS NUMBER NULL, LATE_FEES NUMBER NULL, constraint PAYMENTS_PAYMENTNO_PK primary key (PAYMENT_NO) ); I am trying to find how many late orders each customer have. the column late_days in PAYMENTS table has how many days the customer is late for making payments for any particular order. so I am making this query SELECT C.CUSTOMER_NO, C.lname, C.fname, sysdate, COUNT(P.ORDER_NO) as number_LATE_ORDERS FROM CUSTOMER C, orders o, PAYMENTS P WHERE C.CUSTOMER_NO = o.CUSTOMER_NO AND P.order_no = o.order_no AND P.LATE_DAYS>0 group by C.CUSTOMER_NO, C.lname, C.fname That means, I am counting the orders those have any late payments and late_days0. But this is giving me only the customers who have any orders with late_days0, but the customers who does not have any late orders are not showing up. so if one customer has 5 orders with late payments then it is showing 5 for that customer, but if a customer have 0 late orders,that customer is not selected in this query. Is there any way to select all the customers , and if he has any late orders, it will show the number and also if he does not have any late orders, it will show 0.

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  • method for creating PHP templates (ie html with variables)?

    - by Haroldo
    I'm designing my html emails, these are to be a block of html containing variables that i can store in a $template variable. My problem comes with the storing in the variable part. putting all my html into php makes it a pain in the bum to work with. for example, the below code is fine for a simple email but once i start getting nested tables etc its going to get really confusing... $template.= 'Welcome ' . $username . '<br /><br /><br />'; $template.= 'Thank-you for creating an account <br /><br />'; $template.= 'Please confirm your account by click the link below! <br /><br />'; $template.= '<a href="' . $sitepath . '?email=' . $email . '&conf_key=' . $key . '" style="color: #03110A;"><font size="5" font-family="Verdana, Geneva, sans-serif" color="#03110A">' . $key . '</font></a>'; $template.='</body></html>'; is there a way i can still store the html in a $var but not have to write it like this?

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  • Slow query. Wrong database structure?

    - by Tin
    I have a database with table that contains tasks. Tasks have a lifecycle. The status of the task's lifecycle can change. These state transitions are stored in a separate table tasktransitions. Now I wrote a query to find all open/reopened tasks and recently changed tasks but I already see with a rather small number of tasks (<1000) that execution time has becoming very long (0.5s). Tasks +-------------+---------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-------------+---------+------+-----+---------+----------------+ | taskid | int(11) | NO | PRI | NULL | auto_increment | | description | text | NO | | NULL | | +-------------+---------+------+-----+---------+----------------+ Tasktransitions +------------------+-----------+------+-----+-------------------+----------------+ | Field | Type | Null | Key | Default | Extra | +------------------+-----------+------+-----+-------------------+----------------+ | tasktransitionid | int(11) | NO | PRI | NULL | auto_increment | | taskid | int(11) | NO | MUL | NULL | | | status | int(11) | NO | MUL | NULL | | | description | text | NO | | NULL | | | userid | int(11) | NO | | NULL | | | transitiondate | timestamp | NO | | CURRENT_TIMESTAMP | | +------------------+-----------+------+-----+-------------------+----------------+ Query SELECT tasks.taskid,tasks.description,tasklaststatus.status FROM tasks LEFT OUTER JOIN ( SELECT tasktransitions.taskid,tasktransitions.transitiondate,tasktransitions.status FROM tasktransitions INNER JOIN ( SELECT taskid,MAX(transitiondate) AS lasttransitiondate FROM tasktransitions GROUP BY taskid ) AS tasklasttransition ON tasklasttransition.lasttransitiondate=tasktransitions.transitiondate AND tasklasttransition.taskid=tasktransitions.taskid ) AS tasklaststatus ON tasklaststatus.taskid=tasks.taskid WHERE tasklaststatus.status IS NULL OR tasklaststatus.status=0 or tasklaststatus.transitiondate>'2013-09-01'; I'm wondering if the database structure is best choice performance wise. Could adding indexes help? I already tried to add some but I don't see great improvements. +-----------------+------------+----------------+--------------+------------------+-----------+-------------+----------+--------+------+------------+---------+---------------+ | Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment | +-----------------+------------+----------------+--------------+------------------+-----------+-------------+----------+--------+------+------------+---------+---------------+ | tasktransitions | 0 | PRIMARY | 1 | tasktransitionid | A | 896 | NULL | NULL | | BTREE | | | | tasktransitions | 1 | taskid_date_ix | 1 | taskid | A | 896 | NULL | NULL | | BTREE | | | | tasktransitions | 1 | taskid_date_ix | 2 | transitiondate | A | 896 | NULL | NULL | | BTREE | | | | tasktransitions | 1 | status_ix | 1 | status | A | 3 | NULL | NULL | | BTREE | | | +-----------------+------------+----------------+--------------+------------------+-----------+-------------+----------+--------+------+------------+---------+---------------+ Any other suggestions?

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  • Is this multi line if statement too complex?

    - by AndHeCodedIt
    I am validating input on a form and attempting to prompt the user of improper input(s) based on the combination of controls used. For example, I have 2 combo boxes and 3 text boxes. The 2 combo boxes must always have a value other than the first (default) value, but one of three, or two of three, or all text boxes can be filled to make the form valid. In one such scenario I have a 6 line if statement to try to make the test easily readable: if ((!String.Equals(ComboBoxA.SelectedValue.ToString(), DEFAULT_COMBO_A_CHOICE.ToString()) && !String.IsNullOrEmpty(TextBoxA.Text) && !String.Equals(ComboBoxB.SelectedValue.ToString(), DEFAULT_COMBO_B_CHOICE.ToString())) || (!String.IsNullOrEmpty(TextBoxB.Text) || !String.IsNullOrEmpty(TextBoxC.Text))) { //Do Some Validation } I have 2 questions: Should this type of if statement be avoided at all cost? Would it be better to enclose this test in another method? (This would be a good choice as this validation will happen in more than one scenario) Thanks for your input(s)!

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  • Is there anything like Zope Page Templates for Ruby on Rails?

    - by dan
    I have a Ruby on Rails app that I built myself, but which needs a redesign by a professional designer. I know most designers just give you Photoshop mockups and slices, but I would like to hire someone to implement the design as well, which means rewriting the css style sheets and the erb and haml templates. The problem is that I want someone else to implement the redesign without exposing my business logic code to the redesign implementer. Also, I wish there was a way to allow a designer to implement a redesign on a Ruby on Rails site without having to know anything about Ruby on Rails. Are either of these scenarios possible using any combination of software tools? I guess I'm looking for something like Zope Page Templates, but for Ruby on Rails. http://quintagroup.com/cms/zpthttp://quintagroup.com/cms/zpt

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  • database table design

    - by e.b.white
    I design the tables as below for the system which looks like a package delivering system For example, after user received the package, postman should record in system, and the state(history table) is "delivered",and operator is this postman, the current state(state table) is of course "delivered" history table: +---------------+--------------------------+ | Field | Desc | +---------------+--------------------------+ | id | PRIMARY KEY | +---------------+--------------------------+ | package_id | package_tacking_id | +---------------+--------------------------+ | state | package_state | +---------------+--------------------------+ | operators | operators | +---------------+--------------------------+ | create_time| create_time | +---------------+--------------------------+ state table: +---------------+--------------------------+ | Field | Desc | +---------------+--------------------------+ | id | PRIMARY KEY | +---------------+--------------------------+ | package_id | package_tacking_id | +---------------+--------------------------+ | state | latest_package_state | +---------------+--------------------------+ Above is just the basic information to record, some other information( like invoice, destination,...) should be recored as well. But there are different service types like s1 and s2, for s1 it is not needed to record invoice but s1 need, and maybe s1 need some other information to record (like the tel of end user). After all, at delivering way stations there are additional information to record, and for different service type the information type is different. My question is: 1. For different service type, shall I need to declare different tables(option A) or just one big table which can record all information for all types(option B)? 2. If option A, since the basic information above is MUST, how can prevent from declaring there duplicate fields in different tables?

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  • .NET port with Java's Map, Set, HashMap

    - by Nikos Baxevanis
    I am porting Java code in .NET and I am stuck in the following lines that (behave unexpectedly in .NET). Java: Map<Set<State>, Set<State>> sets = new HashMap<Set<State>, Set<State>>(); Set<State> p = new HashSet<State>(); if (!sets.containsKey(p)) { ... } The equivalent .NET code could possibly be: IDictionary<HashSet<State>, HashSet<State>> sets = new Dictionary<HashSet<State>, HashSet<State>>(); HashSet<State> p = new HashSet<State>(); if (!sets.containsKey(p)) { /* (Add to a list). Always get here in .NET (??) */ } However the code comparison fails, the program think that "sets" never contain Key "p" and eventually results in OutOfMemoryException. Perhaps I am missing something, object equality and identity might be different between Java and .NET. I tried implementing IComparable and IEquatable in class State but the results were the same. Edit: What the code does is: If the sets does not contain key "p" (which is a HashSet) it is going to add "p" at the end of a LinkedList. The State class (Java) is a simple class defined as: public class State implements Comparable<State> { boolean accept; Set<Transition> transitions; int number; int id; static int next_id; public State() { resetTransitions(); id = next_id++; } // ... public int compareTo(State s) { return s.id - id; } public boolean equals(Object obj) { return super.equals(obj); } public int hashCode() { return super.hashCode(); }

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