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  • new Stateful session bean instance without calling lookup

    - by kislo_metal
    Scenario: I have @Singleton UserFactory (@Stateless could be) , its method createSession() generating @Stateful UserSession bean by manual lookup. If I am injecting by DI @EJB - i will get same instance during calling fromFactory() method(as it should be) What I want - is to get new instance of UserSession without preforming lookup. Q1: how could I call new instance of @Stateful session bean? Code: @Singleton @Startup @LocalBean public class UserFactory { @EJB private UserSession session; public UserFactory() { } @Schedule(second = "*/1", minute = "*", hour = "*") public void creatingInstances(){ try { InitialContext ctx = new InitialContext(); UserSession session2 = (UserSession) ctx.lookup("java:global/inferno/lic/UserSession"); System.out.println("in singleton UUID " +session2.getSessionUUID()); } catch (NamingException e) { e.printStackTrace(); } } @Schedule(second = "*/1", minute = "*", hour = "*") public void fromFactory(){ System.out.println("in singleton UUID " +session.getSessionUUID()); } public UserSession creatSession(){ UserSession session2 = null; try { InitialContext ctx = new InitialContext(); session2 = (UserSession) ctx.lookup("java:global/inferno/lic/UserSession"); System.out.println("in singleton UUID " +session2.getSessionUUID()); } catch (NamingException e) { e.printStackTrace(); } return session2; } } As I understand, calling of session.getClass().newInstance(); is not a best idea Q2 : is it true? I am using glassfish v3, ejb 3.1.

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  • Howto create dynamic named folders with Maven2 Archetype?

    - by chrsk
    Hey, i try to build a structure like this +---src +---main +---webapp +---WEB-INF +---cfg ¦ +---log4j ¦ +---resources ¦ +---extensions ¦ +---${artifactIdKey}-business ¦ +---${artifactIdKey}-layout +---lib I added a required property to my archetype-metadata.xml to have an short-name for the project, which is used among other things for generating unique folders. <requiredProperties> <requiredProperty key="artifactIdKey" /> </requiredProperties> The property artifactIdKey i use in a fileSet: <fileSet> <directory>[..]/resources/extensions/${artifactIdKey}-business</directory> </fileSet> <fileSet> <directory>[..]/resources/extensions/${artifactIdKey}-layout</directory> </fileSet> The command to generate the archetype: mvn archetype:generate -B \ -DgroupId=com.stackoverflow \ -DartifactId=stackoverflow-question -DarchetypeGroupId=com.stackoverflow \ -DarchetypeArtifactId=stackoverflow-archetype -DarchetypeVersion=1.0 \ -DartifactIdKey=soq I assume to get the following folder structure, but i get the ${artifactIdKey} property as folder. Without beeing replaces. ..\ +---soq-business +---soq-layout ..\ +---${artifactIdKey}-business +---${artifactIdKey}-layout How can i achieve this? And how can i place files below soq-business? Without knowing the folder name at this time?

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  • From where to send mails in a MVC framework, so that there is no duplication of code?

    - by Sabya
    It's a MVC question. Here is the situation: I am writing an application where I have "groups". You can invite other persons to your groups by typing their email and clicking "invite". There are two ways this functionality can be called: a) web interface and b) API After the mail sending is over I want to report to the user which mails were sent successfully (i.e., if the SMTP send succeeded. Currently, I am not interested in reporting mail bounces). So, I am thinking how should I design so that there is no code duplication. That is, API and web-interface should share the bulk of the code. To do this, I can create the method "invite" inside the model "group". So, the API and and the Web-interface can just call: group-invite($emailList); This method can send the emails. But the, problem is, then I have to access the mail templates, create the views for the mails, and then send the mails. Which should actually be in the "View" part or at least in the "Controller" part. What is the most elegant design in this situation? Note: I am really thinking to write this in the Model. My only doubt is: previously I thought sending mails also as "presentation". Since it is may be considered as a different form of generating output.

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  • Unit test project doesn't recognize the classes it was generated from

    - by DougLeary
    I have a fairly simple file-system website consisting of one aspx page and several classes in separate .cs files. Everything is on my own HD. The web app itself builds and runs fine. Out of curiosity I decided to try out Visual Studio's nifty, easy-to-use unit test feature. So I opened each class file and clicked Create Unit Tests. VS generated a test project containing a set of test classes and some other files. Easy! But when I try to build or run the test project it throws a series of build errors, one for every class: The type or namespace name 'class-name' could not be found (are you missing a using directive or an assembly reference?). Somebody asked if my test project has a reference to the original project. Well no, because the original project is a file-system website. It has no bin folder and no DLL, so there's nothing to reference as far as I can tell. I would think that since VS generated these unit tests it would generate whatever references it needs, but apparently not. Is generating unit tests for file-system web apps an undocumented no-no, or is there a magic trick to getting it to work?

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  • Sorting by custom field and fetching whole tree from DB

    - by Niaxon
    Hello everyone, I am trying to do file browser in a tree form and have a problem to sort it somehow. I use PHP and MySQL for that. I've created mixed (nested set + adjacency) table 'element' with the following fields: element_id, left_key, right_key, level, parent_id, element_name, element_type (enum: 'folder','file'), element_size. Let's not discuss right now that it is better to move information about element (name, type, size) into other table. Function to scan specified directory and fill table work correctly. Noteworthy, i am adding elements to tree in specific order: folders first and then files. After that i can easily fetch and display whole table on the page using simple query: SELECT * FROM element WHERE 1=1 ORDER BY left_key With the result of that query and another function i can generate correct html code (<ul><li>... and so on). to display tree. Now back to the question (finally, huh?). I am struggling to add sorting functionality. For example i want to order my result by size. Here i need to keep in my mind whole hierarchy of tree and rule: folders first, files later. I believe i can do that by generating in PHP recursive query: SELECT * FROM element WHERE parent_id = {$parentId} ORDER BY element_type (so folders would be first), size (or name for example) asc/desc After that for each result which has type = 'folder' i will send another query to get it's content. Also it's possible to fetch whole tree by left_key and after that sort it in PHP as array but i guess that would be worse :) I wonder if there is better and more efficient way to do such a thing?

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  • Controller changes format on variables when publishing

    - by Christoffer
    I am a newbie to ROR but catching on quickly. I have been working on this problem for a couple of hours now and it seems like a bug. I does not make any sense. I have a database with the following migration: class CreateWebsites < ActiveRecord::Migration def self.up create_table :websites do |t| t.string :name t.integer :estimated_value t.string :webhost t.string :purpose t.string :description t.string :tagline t.string :url t.integer :adsense t.integer :tradedoubler t.integer :affiliator t.integer :adsense_cpm t.boolean :released t.string :empire_type t.string :oldid t.string :old_outlink_policy t.string :old_inlink_policy t.string :old_priority t.string :old_profitability t.integer :priority_id t.integer :project_id t.integer :outlink_policy_id t.integer :inlink_policy_id t.timestamps end end def self.down drop_table :websites end end I have verified that what is created in the database also is integers, strings etc according to this migration. I have not touched the controller after generating it through scaffold, i.e. it is the standard controller with show, index etc. Now. When I enter data into the database, either through the web form, in rails console or directly in the database - such as www.domain.com for url or 500 for adsense - it will be created in the db without problem. However, when it is being published on the website the variables go completely nuts. Adsense (integer) turns into date, url (string) turns into a float, and so on. This only happens to a few of the variables. This will also create a problem with "argument out of range" since I input 500 and Rails will try to output it as date = crash and "argument out of range". So, how do I fix/trouble shoot this? Why do the formats change? Could it be because of the respond_to in the controller? Cheers, Christoffer

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  • Using maven to distribute a swing application that can have each dependency individually tracked

    - by tms
    I'm moving my project to Maven and eventually OSGi. I currently distribute the project is a large Zip file with all the dependencies. Although my projects code is only 20% of the total package I have to redistribute all the dependency. With smaller independent modules this may be even less. Looking here on stack overflow it seems that to keep my current plan the maven-assembly-plugin should do the trick. I was considering having a base installer that would look at a XML manifest, then collect all the libraries that needed to be updated. This would mean that libraries that change occasionally would be downloaded less often. This also makes since for something like OSGi plugins (which could have independent release schedules). In essence I want my software to look and manage individual libraries, and download on demand (based on the manifest). I was wondering if there is a "maven way" of generating this Manifest and publishing all the libraries to a website? I believe the deploy life-cycle would do the second step. As an alternative, is there a OpenSource Java library that does this type of deployment? I don't want to embed Maven or something larger with the distributed code. The application is not for coders, the simpler the better, and the smaller the installer the better.

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  • PHP: saving multiple tuples to the same table

    - by Binaryrespawn
    Hi all, I am trying to save data into the same table several times from the same $_POST array. You see, on my registration form a family is allowed to specify the names, gender and age of all members they wish to bring along. This data is being stored in a database table called aditional_member. Based on family size, I am dynamically generating html table rows where each row has the number of input fields required. <tr id="additionalmember_3"> <td><input type="text" name="first_name1" maxlength="50" value="" /></td> <td><input type="text" name="last_name1" maxlength="50" value="" /></td> td><select name="gender1" value="" ><option value='Male'>Male</option><option value='Female'>Female</option></select></td> <td><select name="age_group"value="" ><option value='18 to 30'>18 to 30</option><option value='31 to 60'>31 to 60</option></select></td> </tr> When I POST, let us say I have three sets of input(3 table rows as above), Is there a simple way to insert into the addional_member table the data from row one, then row two, and so on. I tried looping the insert statement, which failed. I am basically open to suggestions, I do not need to use a table. Any ideas, Thank you.

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  • Best way to dynamically get column names from oracle tables

    - by MNC
    Hi, We are using an extractor application that will export data from the database to csv files. Based on some condition variable it extracts data from different tables, and for some conditions we have to use UNION ALL as the data has to be extracted from more than one table. So to satisfy the UNION ALL condition we are using nulls to match the number of columns. Right now all the queries in the system are pre-built based on the condition variable. The problem is whenever there is change in the table projection (i.e new column added, existing column modified, column dropped) we have to manually change the code in the application. Can you please give some suggestions how to extract the column names dynamically so that any changes in the table structure do not require change in the code? My concern is the condition that decides which table to query. The variable condition is like if the condition is A, then load from TableX if the condition is B then load from TableA and TableY. We must know from which table we need to get data. Once we know the table it is straightforward to query the column names from the data dictionary. But there is one more condition, which is that some columns need to be excluded, and these columns are different for each table. I am trying to solve the problem only for dynamically generating the list columns. But my manager told me to make solution on the conceptual level rather than just fixing. This is a very big system with providers and consumers constantly loading and consuming data. So he wanted solution that can be general. So what is the best way for storing condition, tablename, excluded columns? One way is storing in database. Are there any other ways? If yes what is the best? As I have to give at least a couple of ideas before finalizing. Thanks,

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  • How to generate lots of redundant ajax elements like checkboxes and pulldowns in Django?

    - by iJames
    Hello folks. I've been getting lots of answers from stackoverflow now that I'm in Django just be searching. Now I hope my question will also create some value for everybody. In choosing Django, I was hoping there was some similar mechanism to the way you can do partials in ROR. This was going to help me in two ways. One was in generating repeating indexed forms or form elements, and also in rendering only a piece of the page on the round trip. I've done a little bit of that by using taconite with a simple URL click but now I'm trying to get more advanced. This will focus on the form issue which boils down to how to iterate over a secondary object. If I have a list of photo instances, each of which has a couple of parameters, let's say a size and a quantity. I want to generate form elements for each photo instance separately. But then I have two lists I want to iterate on at the same time. Context: photos : Photo.objects.all() and forms = {} for photo in photos: forms[photo.id] = PhotoForm() In other words we've got a list of photo objects and a dict of forms based on the photo.id. Here's an abstraction of the template: {% for photo in photos %} {% include "photoview.html" %} {% comment %} So here I want to use the photo.id as an index to get the correct form. So that each photo has its own form. I would want to have a different action and each form field would be unique. Is that possible? How can I iterate on that? Thanks! {% endcomment %} Quantity: {{ oi.quantity }} {{ form.quantity }} Dimensions: {{ oi.size }} {{ form.size }} {% endfor %} What can I do about this simple case. And how can I make it where every control is automatically updating the server instead of using a form at all? Thanks! James

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  • How to generate XML from an Excel VBA macro?

    - by SuperNES
    So, I've got a bunch of content that was delivered to us in the form of Excel spreadsheets. I need to take that content and push it into another system. The other system takes its input from an XML file. I could do all of this by hand (and trust me, management has no problem making me do that!), but I'm hoping there's an easy way to write an Excel macro that would generate the XML I need instead. This seems like a better solution to me, as this is a job that will need to be repeated regularly (we'll be getting a LOT of content in Excel sheets) and it just makes sense to have a batch tool that does it for us. However, I've never experimented with generating XML from Excel spreadsheets before. I have a little VBA knowledge but I'm a newbie to XML. I guess my problem in Googling this is that I don't even know what to Google for. Can anyone give me a little direction to get me started? Does my idea sound like the right way to approach this problem, or am I overlooking something obvious? Thanks StackOverflow!

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  • Symfony2 Theming form generated by embedded controller action

    - by user1112057
    I am generating the form in embedded controller action. And now i have faced the following problem. The Form Theming is not working in that case. So what i have: The tempalte "page.html.twig" {% block content %} {% render 'MyBundle:Widget:index' %} {% endblock %} The indexAction() creates the form and rendering another template "form.html.twig" which is normally renders a form using form_row, form_rest and so on. So, now i am trying to customize form theming, and here is my problem. When i put the code {% form_theme form _self %} in the page.html.twig, i got an error the the form variable does not exists. And its correct, the form var is created later in the embedded controller. But when i put the theming code in embedded template "form.html.twig", i got another error "Variable "compound" does not exist" {% block form_label %} {% spaceless %} {% if not compound %} {% set label_attr = label_attr|merge({'for': id}) %} {% endif %} {% if required %} {% set label_attr = label_attr|merge({'class': (label_attr.class|default('') ~ ' required')|trim}) %} {% endif %} {% if label is empty %} {% set label = name|humanize %} {% endif %} <label{% for attrname, attrvalue in label_attr %} {{ attrname }}="{{ attrvalue }}"{% endfor %} {% if attr.tooltip is defined %}title="{{ attr.tooltip }}"{% endif %}>{{ label|trans({}, translation_domain) }}{% if required %}<span>*</span>{% endif %}</label> {% endspaceless %} {% endblock form_label %} This part of code was copied from this file https://github.com/symfony/symfony/blob/2.1/src/Symfony/Bridge/Twig/Resources/views/Form/form_div_layout.html.twig So tried someone to do something like this?

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  • Insert data in an object to a database.

    - by paul
    I am facing the following design/implementation dilemma. I have a class Customer which is below with getters and setters. I would like to insert the value of the Customer into a "Customer" table of a database. But Customer has an address which is of type "Address". How do I go about inserting this field into the database?(I am using sqlite3). I thought of writing a separate table "Address(customerId,doorNo,city,state,country,pinCode)". But I am having second thoughts about generating the primary key(customerId) which should be same for both the "customer" and "Address" table. Sqlite3 faq states that I can do "Integer Primary Key" to use the field to generate an auto number. But if I do that in customer table, I would have to retrieve the same Id to be used in Address table. This kinda looks wrong to me :-?. There should be an elegant method to solve this. Any ideas would be much appreciated. Thanks in advance. import java.io.*; import java.sql.*; class Customer { private String id; private String name; private Address address; private Connection connection; private ResultSet resultSet; private PreparedStatement preparedStatement; public void insertToDatabase(){ } } class Address{ private String doorNumber; private String streetName; private String cityName; private String districtName; private String stateName; private String countryName; private long pinCode; }

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  • Way to store a large dictionary with low memory footprint + fast lookups (on Android)

    - by BobbyJim
    I'm developing an android word game app that needs a large (~250,000 word dictionary) available. I need: reasonably fast look ups e.g. constant time preferable, need to do maybe 200 lookups a second on occasion to solve a word puzzle and maybe 20 lookups within 0.2 second more often to check words the user just spelled. EDIT: Lookups are typically asking "Is in the dictionary?". I'd like to support up to two wildcards in the word as well, but this is easy enough by just generating all possible letters the wildcards could have been and checking the generated words (i.e. 26 * 26 lookups for a word with two wildcards). as it's a mobile app, using as little memory as possible and requiring only a small initial download for the dictionary data is top priority. My first naive attempts used Java's HashMap class, which caused an out of memory exception. I've looked into using the SQL lite databases available on android, but this seems like overkill. What's a good way to do what I need?

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  • Disable validation in an object in Ruby on Rails

    - by J. Pablo Fernández
    I have an object which whether validation happens or not should depend on a boolean, or in another way, validation is optional. I haven't found a clean way to do it. What I'm currently doing is this (disclaimer: you cannot unsee, leave this page if you are too sensitive): def valid? if perform_validation super else super # Call valid? so that callbacks get called and things like encrypting passwords and generating salt in before_validation actually happen errors.clear # but then clear the errors true # and claim ourselves to be valid. This is super hacky! end end Any better ways? Before you point to the :if argument of many validations, this is for a user model which is using authlogic so it has a lot of validation rules. You can stop reading here if you belive me. If you don't, authlogic already sets some :ifs like: :if => :email_changed? which I have to turn into :if => Proc.new {|user| user.email_changed? and user.perform_validation} and in some other cases, since I'm also using authlogic-oid (OpenID) I just don't have control over the :if, authlogic-oid sets it in a way I cannot change it (in time) without further monkey patching. So I have to override seemingly unrelated functions, catch exceptions if a method doesn't exist, etc. The previous hacky solution if the best of my two attempts.

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  • How to prepare data for display on a silverlight chart using WCF RIA Services + Entity Framework

    - by Banford
    I've used WCF RIA services with Entity Framework to build a simple application which can display and updates data about school courses. This was done by following the Microsoft tutorials. Now I would like to have a chart which shows a count for how many courses are on a key stage. Example: Key Stage 3 - 20 courses Key Stage 4 - 32 courses Key Stage 5 - 12 courses Displayed on any form of chart. I have no problem binding data to the chart in XAML. My problem is that I do not know how to correct way of getting the data into that format. The generated CRUD methods are basic. I have a few thoughts about possible ways, but don't know which is correct, they are: Create a View in SQL server and map this to a separate Entity in the Entity Data Model. Generating new CRUD methods for this automatically. Customise the read method in the existing DomainService using .Select() .Distinct() etc. Don't know this syntax very well labda expressions/LINQ??? what is it? Any good quickstarts on it? Create a new class to store only the data required and create a read method for it. Tried this but didn't know how to make it work without a matching entity in the entity model. Something I am not aware of. I'm very new to this and struggling with the concepts so if there are useful blogs or documentation I've missed feel free to point me towards them. But I'm unsure of the terminology to use in my searches at the moment.

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  • Where is the taglib definition of PrimeFaces 4?

    - by Michael Wölm
    I am looking around how to define custom components in JSF. According to the Java EE tutorial, any custom component needs to be described in a taglib. When I take a look into the PrimeFaces source, I cannot find any taglib file or any hint where the namespace is bound and the available components are defined. I am adding primefaces jar to my dependencies, adding xmlns:p="http://primefaces.org/ui to the xml namespace, defining some primfaces components on my page and it works... Ok, but neither I can find the related taglib in the source or binary package nor my IDE (IntelliJ) is able to find where "xmlns:p="http://primefaces.org/ui" is pointing to. Therefore, code completion is also not possible. (all other mojarra taglibs are found.) Is it possible that PrimeFaces is defining the taglib via annotations directly in Java classes or is it generating it during runtime? I can easily find the UIComponents, primefaces defines in its source, but the configuration of the taglib seems to be missing. I am sure I just don't know how PrimeFaces is doing it, but the javaeetutorial is not describing any other opportunity than defining a ...-taglib.xml

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  • Editing a remote file on-the-fly with PHP

    - by user275074
    Hi, I have a requirement to edit a remote text file on-the-fly, the content of which currently stands at ~1Mb. I have tried a couple of approaches and both seem to be clunky or hog memory which I can't rely on. Thinking out logically what I'm trying to achieve is: FTP to a remote server. Download a copy of the file for backup purposes and store it somewhere locally. Open the remote file and add the necessary lines required. Remove lines from the remote file as per an array of un-required data generated from the local server. Is this possible? I've managed to code steps 1 and 2 but I'm having difficult with 3 and 4. The way I'm doing it now is to use fgets and return the whole string. Really, I don't want to do this as it involves manipulating and re-generating the whole string (and it's large) and then re-inserting it in between two markers in the remote file. Is there no way of manipulating the lines of text in the file on-the-fly?

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  • Should I use IDisposable for purely managed resources?

    - by John Gietzen
    Here is the scenario: I have an object called a Transaction that needs to make sure that only one entity has permission to edit it at any given time. In order to facilitate a long-lived lock, I have the class generating a token object that can be used to make the edits. You would use it like this: var transaction = new Transaction(); using (var tlock = transaction.Lock()) { transaction.Update(data, tlock); } Now, I want the TransactionLock class to implement IDisposable so that its usage can be clear. But, I don't have any unmanaged resources to dispose. however, the TransctionLock object itself is a sort of "unmanaged resource" in the sense that the CLR doesn't know how to properly finalize it. All of this would be fine and dandy, I would just use IDisposable and be done with it. However, my issue comes when I try to do this in the finalizer: ~TransactionLock() { this.Dispose(false); } I want the finalizer to release the transaction from the lock, if possible. How, in the finalizer, do I detect if the parent transaction (this.transaction) has already been finalized? Is there a better pattern I should be using? The Transaction class looks something like this: public sealed class Transaction { private readonly object lockMutex = new object(); private TransactionLock currentLock; public TransactionLock Lock() { lock (this.lockMutex) { if (this.currentLock != null) throw new InvalidOperationException(/* ... */); this.currentLock = new TransactionLock(this); return this.currentLock; } } public void Update(object data, TransactionLock tlock) { lock (this.lockMutex) { this.ValidateLock(tlock); // ... } } internal void ValidateLock(TransactionLock tlock) { if (this.currentLock == null) throw new InvalidOperationException(/* ... */); if (this.currentLock != tlock) throw new InvalidOperationException(/* ... */); } internal void Unlock(TransactionLock tlock) { lock (this.lockMutex) { this.ValidateLock(tlock); this.currentLock = null; } } }

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  • how to apply group by on xslt elements

    - by Amit
    Hello All, I need to group the value based on some attribute and populate it. below mentioned is i/p xml and if you see there are 4 rows for Users and for id 2,4 Division is same i.e. HR while generating actual o/p I need to group by Division ... Any help ??? I/P XML <Users> <User id="2" name="ABC" Division="HR"/> <User id="3" name="xyz" Division="Admin"/> <User id="4" name="LMN" Division="Payroll"/> <User id="5" name="PQR" Division="HR"/> </Users> expected Result: I need to group the values based on Division and populate i.e. <AllUsers> <Division value="HR"> <User> <id>2</id> <name>ABC</name> </User> <User> <id>5</id> <name>PQR</name> </User> </Division> <Division value="ADMIN"> <User> <id>3</id> <name>XYZ</name> </User> </Division> <Division value="Payroll"> <User> <id>4</id> <name>LMN</name> </User> </Division> </AllUsers>

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  • Designing small comparable objects

    - by Thomas Ahle
    Intro Consider you have a list of key/value pairs: (0,a) (1,b) (2,c) You have a function, that inserts a new value between two current pairs, and you need to give it a key that keeps the order: (0,a) (0.5,z) (1,b) (2,c) Here the new key was chosen as the average between the average of keys of the bounding pairs. The problem is, that you list may have milions of inserts. If these inserts are all put close to each other, you may end up with keys such to 2^(-1000000), which are not easily storagable in any standard nor special number class. The problem How can you design a system for generating keys that: Gives the correct result (larger/smaller than) when compared to all the rest of the keys. Takes up only O(logn) memory (where n is the number of items in the list). My tries First I tried different number classes. Like fractions and even polynomium, but I could always find examples where the key size would grow linear with the number of inserts. Then I thought about saving pointers to a number of other keys, and saving the lower/greater than relationship, but that would always require at least O(sqrt) memory and time for comparison. Extra info: Ideally the algorithm shouldn't break when pairs are deleted from the list.

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  • How would I code a complex formula parser manually?

    - by StormianRootSolver
    Hm, this is language - agnostic, I would prefer doing it in C# or F#, but I'm more interested this time in the question "how would that work anyway". What I want to accomplish ist: a) I want to LEARN it - it's about my ego this time, it's for a fun project where I want to show myself that I'm a really good at this stuff b) I know a tiny little bit about EBNF (although I don't know yet, how operator precedence works in EBNF - Irony.NET does it right, I checked the examples, but this is a bit ominous to me) c) My parser should be able to take this: 5 * (3 + (2 - 9 * (5 / 7)) + 9) for example and give me the right results d) To be quite frankly, this seems to be the biggest problem in writing a compiler or even an interpreter for me. I would have no problem generating even 64 bit assembler code (I CAN write assembler manually), but the formula parser... e) Another thought: even simple computers (like my old Sharp 1246S with only about 2kB of RAM) can do that... it can't be THAT hard, right? And even very, very old programming languages have formula evaluation... BASIC is from 1964 and they already could calculate the kind of formula I presented as an example f) A few ideas, a few inspirations would be really enough - I just have no clue how to do operator precedence and the parentheses - I DO, however, know that it involves an AST and that many people use a stack So, what do you think?

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  • How should I configure grub for booting linux kernel from a USB hard drive?

    - by skolima
    I have a laptop hard drive in an external enclosure which I use as a large pendrive. For an added twist, I have installed Linux on it, so I can boot any machine with my distribution of choice (e.g. for data recovery or repairing a b0rked system or just using a borrowed laptop without destroying the preinstalled Windows). The problem is that, depending on the hardware configuration, the USB hard drive may be visible under different paths. For grub configuration I just use (hda0,0) as it is relative to the device the grub was launched from. I have UUID entries in /etc/fstab. I also specify rootwait in the kernel parameters so that it waits for the USB subsystem to settle down before trying to mount the device. What should I pass to the kernel as root= ? Currently boot from the pendrive once, check the debug messages to see what /dev/sdX device has been assigned to the USB drive by the kernel, then reboot and edit the grub configuration. I can't change anything on the PC besides enabling Boot from USB hard drive in BIOS and setting it to higher priority than internal hard drives. There are various initrd generating scripts which include support for UUID in root device path, unfortunately the Gentoo native one (genkernel) does not support rootwait and I had no luck trying to use others. The boot process goes like this (it is quite similar in Windows): The BIOS chooses the boot device and loads whatever is its MBR (which happens to be grub stage-1). Grub loads it's configuration and stage-2 files from device it has set as root, using (hd0) for the device it was loaded from by BIOS. Grub loads and starts a kernel (still the same numbering, so I can use (hd0,0) again ). Kernel initializes all built-in devices (rootwait does it's magic now). Kernel mounts the partition it was passed as root (this is a kernel parameter, not grub parameter). init.d starts the userland booting process, including mounting things from /etc/fstab. Part 5 is the one giving me problems.

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  • Export to csv in jQuery

    - by Rahul Joshi
    I am dynamically generating a div which is like : <div id='PrintDiv'> <table id="mainTable"> <tr> <td> Col1 </td> <td> Col2 </td> <td> Col3 </td> </tr> <tr> <td> Val1 </td> <td> Val2 </td> <td> Val3 </td> </tr> <tr> <td> Val11 </td> <td> Val22 </td> <td> Val33 </td> </tr> <tr> <td> Val111 </td> <td> Val222 </td> <td> Val333 </td> </tr> </table> </div> And there are lot more elements on the page as well. Now, how can i get a csv file like this : Col1,Col2,Col3 Val1,Val2,Val3 Val11,Val22,Val33 Val111,Val222,Val333 using jQuery ? need a file save dailog box too,like this : Thanks.

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  • Extract data from PostgreSQL DB without using pg_dump

    - by John Horton
    There is a PostgreSQL database on which I only have limited access (e.g, I can't use pg_dump). I am trying to create a local "mirror" by exporting certain tables from the database. I do not have the permissions needed to just dump a table as SQL from within psql. Right now, I just have a Python script that iterates through my table_names, selects all fields and then exports them as a CSV: for table_name, file_name in zip(table_names, file_names): cmd = """echo "\\\copy (select * from %s)" to stdout WITH CSV HEADER | psql -d remote_db | gzip > ./%s/%s.gz"""%(table_name,dir_name,file_name) os.system(cmd) I would like to not use CSV if possible, as I lose the field types and the encoding can get messed up. First best would probably be some way of getting the generating SQL code for the table using \copy. Next best would be XML, ideally with some way of preserving the field types. If that doesn't work, I think the final option might be two queries---one to get the field data types, the other to get the actual data. Any thoughts or advice would be greatly appreciated - thanks!

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