boolean logic - Page 258

Relay WCF Service

- by Matt Ruwe

This is more of an architectural and security question than anything else. I'm trying to determine if a suggested architecture is necessary. Let me explain my configuration. We have a standard DMZ established that essentially has two firewalls. One that's external facing and the other that connects to the internal LAN. The following describes where each application tier is currently running. Outside the firewall: Silverlight Application In the DMZ: WCF Service (Business Logic & Data Access Layer) Inside the LAN: Database I'm receiving input that the architecture is not correct. Specifically, it has been suggested that because "a web server is easily hacked" that we should place a relay server inside the DMZ that communicates with another WCF service inside the LAN which will then communicate with the database. The external firewall is currently configured to only allow port 443 (https) to the WCF service. The internal firewall is configured to allow SQL connections from the WCF service in the DMZ. Ignoring the obvious performance implications, I don't see the security benefit either. I'm going to reserve my judgement of this suggestion to avoid polluting the answers with my bias. Any input is appreciated. Thanks, Matt

Read the article

.NET WF4: Should it be in the middle of everything?

- by stimpy77

I am aware that WF4 (Windows Workflow 4.0, part of .NET 4.0) is a significant rework and redesign of WF3, where much of what made WF3 a poor technology choice has been cleaned up in WF4. For example, as far as I can tell, WF4 (Windows Workflow 4.0) activities are more or less testable with [TestMethod] and mocking. This among other things, like improved performance, has grabbed my attention about the technology again, whereas I had previously pooh-poohed WF3. I'm working on a new architecture for essentially an n-tier collaborative application (not enterprise-class, just a smallish project with potential to grow significantly) where I'm already trying to discipline myself to use IoC and, to some extent, TDD, and I'm wondering, in general terms, whether it is wiser to just hand-code workflow logic or if I should delve into learning and integrating WF4 so that WF becomes literally the controller of the entire application, i.e. the practical C in "MVC" (not ASP.NET MVC but rather the pattern). So should workflow activities in WF4 be the primary controller for a highly expandable/growable web-based collaborative application? Or am I asking entirely the wrong question? This is a vague question, I'm sure, so abstract answers are as welcome as specific ones.

Read the article

Limit foreign key choices in select in an inline form in admin

- by mightyhal

Edited :-) Hopefully a bit clearer now. The logic is of the model is: A Building has many Rooms A Room may be inside another Room (a closet, for instance--ForeignKey on 'self') A Room can only in inside of another Room in the same building (this is the tricky part) Here's the code I have: #spaces/models.py from django.db import models class Building(models.Model): name=models.CharField(max_length=32) def __unicode__(self): return self.name class Room(models.Model): number=models.CharField(max_length=8) building=models.ForeignKey(Building) inside_room=models.ForeignKey('self',blank=True,null=True) def __unicode__(self): return self.number and: #spaces/admin.py from ex.spaces.models import Building, Room from django.contrib import admin class RoomAdmin(admin.ModelAdmin): pass class RoomInline(admin.TabularInline): model = Room extra = 2 class BuildingAdmin(admin.ModelAdmin): inlines=[RoomInline] admin.site.register(Building, BuildingAdmin) admin.site.register(Room) The inline will display only rooms in the current building (which is what I want). The problem, though, is that for the inside_room drop down, it displays all of the rooms in the Rooms table (including those in other buildings). In the inline of rooms, I need to limit the inside_room choices to only rooms which are in the current building being displayed by the main form. I can't figure out a way to do it with either a limit_choices_to in the model, nor can I figure out how exactly to override the admin's inline formset properly (I feel like I should be somehow create a custom inline form, pass the building_id of the main form to the custom inline, then limit the queryset for the field's choices based on that--but I just can't wrap my head around how to do it). Maybe this is too complex for the admin site, but it seems like something that would be generally useful... Thanks again for your help!

Read the article

Lucene stop words not removed during searching

- by iamrohitbanga

I have created a Lucene index with the following analyzer. public class DocSpecAnalyzer extends Analyzer { private static CharArraySet stopSet;// = new HashSet<String>(Arrays.asList());//STOP_WORDS_SET; static { stopSet = new CharArraySet(FDConstants.stopwords, true); // uncommenting this displays all the stop words // for (String s: FDConstants.stopwords) { // System.out.println(s); // } } /** * Specifies whether deprecated acronyms should be replaced with HOST type. * See {@linkplain https://issues.apache.org/jira/browse/LUCENE-1068} */ private final boolean enableStopPositionIncrements; private final Version matchVersion; public DocSpecAnalyzer(Version matchVersion) { this.matchVersion = matchVersion; enableStopPositionIncrements = StopFilter.getEnablePositionIncrementsVersionDefault(matchVersion); } public TokenStream tokenStream(String fieldName, Reader reader) { StandardTokenizer tokenStream = new StandardTokenizer(matchVersion, reader); tokenStream.setMaxTokenLength(DEFAULT_MAX_TOKEN_LENGTH); TokenStream result = new StandardFilter(tokenStream); result = new LowerCaseFilter(result); result = new StopFilter(enableStopPositionIncrements, result, stopSet); result = new PorterStemFilter(result); return result; } /** Default maximum allowed token length */ public static final int DEFAULT_MAX_TOKEN_LENGTH = 255; } Now when I search for documents for a query containing stop words, i get hits for stop words also. As I post this problem, I found the bug. It is because of http://lucene.apache.org/java/2_9_2/api/contrib-misc/org/apache/lucene/queryParser/analyzing/AnalyzingQueryParser.html not handling stop words. Is there a substitute? Update: forgot to mention that I need to do a fuzzy search. that is why i am using an AnalyzingQueryParser.

Read the article

Where can I find clear examples of MVC?

- by Tom

I've read a couple of things about MVCs but I still don't understand when they should be used and when they shouldn't be used. I am looking for clear examples that say things like "if you're developing this then you should use MVC, like this" and "if you're developing this, you shouldn't use MVC." Most of the examples I've seen rely on complex frameworks which have already implemented everything and you have to learn the framework and use it a lot to understand what's really happening. To many programmers, phrasings such as "UI business logic" sound like marketing terms — for example, the words "Instead the View binds directly to a Presentation Model" are used in this post. I am aware of the dangers that may lurk in the shadows as MVC is a concept and everyone feels like they know it best, yet nobody really knows exactly how to use it because there may be a lot of variables involved and everyone is allowed to have a different perspective on how to dissect a project into the Model, the View and the Controller. There is a lot of theory out there but very few clear examples. What I'm looking for are not "the best" ways of doing it so this should not be considered as subjective; I'm looking for different simple implementations that would allow me to decide on my own which are the best approaches. Succinctly: What are good on-line resources that present pro and con arguments to using MVC in various situations and provide clear examples to help the reader understand the concept?

Read the article

How to Deserialize Missing Fields To Nulls

- by Nathan

I am working on a .NET project where several versions of the same type of object have been created over the life of the project - most new versions add a field or two. However, now I am looking to mitigate problems for users with an old version. My goal is that when a user tries to open an old version of the serialized object with the new program, the program will automatically assign default values to the fields that are missing from the depreciated version of the file. For example, say I had a class with two boolean fields - RepeatSound and RepeatForever. The first version of the program doesn't know how to repeat forever, so it only saved RepeatSound: <anyType xsi:type="Sound"> <RepeatSound>true</RepeatSound> </anyType> but the new files look like this: <anyType xsi:type="Sound"> <RepeatSound>true</RepeatSound> <RepeatForever>true</RepeatForever> </anyType> My goal is that when I deserialize the first file in the new program that it will create the Sound object but simply default the value of RepeatForever to false. Right now trying to deserialize the first object would throw an exception. Thank you in advance for any responses

Read the article

maven dependencies and jetty - avoiding deploy

- by James Cooper

Hi, I have a project with 3 artifacts: common - entities, business logic. no UI code webapp-a - a public web app webapp-b - an admin web app webapp-a and webapp-b depend on common. common is configured to deploy to a local maven repo. so far so good. I have IntelliJ configured so that each artifact is a separate module. Module dependencies are configured properly. I can add a new method to a class in common and immediately use that method in a class in a webapp. However, when I run mvn jetty:run it uses the currently deployed common snapshot in my repository. It does not use my local classes. If I add a method to a class in common, it compiles fine, but blows up at runtime. So is it possible to either: a) Convince jetty:run to use my local common build output or b) Deploy my common output to my local ~/.m2/repo while I'm testing locally before I want to commit/deploy or c) some other solution? thank you! -- James

Read the article

Infinite loop in regex in java

- by carpediem

Hello, My purpose is to match this kind of different urls: url.com my.url.com my.extended.url.com a.super.extended.url.com and so on... So, I decided to build the regex to have a letter or a number at start and end of the url, and to have a infinite number of "subdomains" with alphanumeric characters and a dot. For example, in "my.extended.url.com", "m" from "my" is the first class of the regex, "m" from "com" is the last class of the regex, and "y.", "extended." and "url." are the second class of the regex. Using the pattern and subject in the code below, I want the find method to return me a false because this url must not match, but it uses 100% of CPU and seems to stay in an infinite loop. String subject = "www.association-belgo-palestinienne-be"; Pattern pattern = Pattern.compile("^[A-Za-z0-9]\\.?([A-Za-z0-9_-]+\\.?)*[A-Za-z0-9]\\.[A-Za-z]{2,6}"); Matcher m = pattern.matcher(subject); System.out.println(" Start"); boolean hasFind = m.find(); System.out.println(" Finish : " + hasFind); Which only prints: Start I can't reproduce the problem using regex testers. Is it normal ? Is the problem coming from my regex ? Could it be due to my Java version (1.6.0_22-b04 / JVM 64 bit 17.1-b03) ? Thanks in advance for helping.

Read the article

searching article for names in the database before submitting article to the database

- by zurna

I want to create a function that will search through a text, find names those match with existing names in the database and add links to those names before submitting the article to the database. i.e. text: Chelsea are making a change now as goalscorer Nicolas Anelka is replaced by in-form Florent Malouda who can do no wrong lately. Nicolas Anelka exists in the database in the Players table with ID column equals to 1. I want text to be converted to Chelsea are making a change now as goalscorer a href="player.asp=ID=1"Nicolas Anelka/a is replaced by in-form Florent Malouda who can do no wrong lately. I know my code is logically wrong but I could build the correct logic. Function PlayerStats (ArticleDesc) If IsNull(ArticleDesc) Then Exit Function SQL = "SELECT PlayerID, PlayerName" SQL = SQL & " FROM Players" ' SQL = SQL & " WHERE PlayerID = "& &"" Set objPlayer = objConn.Execute(SQL) Do While NOT objPlayer.EOF ArticleDesc = Replace(ArticleDesc, objPlayer("PlayerName"), "!"&objPlayer("PlayerName")&"!") PlayerStats = ArticleDesc Loop objPlayer.MoveNext End Function

Read the article

searching article for names in the database before submitting article to the database

- by zurna

I want to create a function that will search through a text, find names those match with existing names in the database and add links to those names before submitting the article to the database. i.e. text: Chelsea are making a change now as goalscorer Nicolas Anelka is replaced by in-form Florent Malouda who can do no wrong lately. Nicolas Anelka exists in the database in the Players table with ID column equals to 1. I want text to be converted to Chelsea are making a change now as goalscorer Nicolas Anelka is replaced by in-form Florent Malouda who can do no wrong lately. I know my code is logically wrong but I could build the correct logic. Function PlayerStats (ArticleDesc) If IsNull(ArticleDesc) Then Exit Function SQL = "SELECT PlayerID, PlayerName" SQL = SQL & " FROM Players" SQL = SQL & " WHERE PlayerID = "& &"" Set objTeam = objConn.Execute(SQL) ArticleDesc = Replace(ArticleDesc, "&", "&") PlayerStats = ArticleDesc End Function

Read the article

Android: Crashed when single contact is clicked

- by Sean Tan

My application is always crashed at this moment, guru here please help me to solved. Thanks.The situation now is as mentioned in title above. Hereby is my AndroidManifest.xml <?xml version="1.0" encoding="utf-8"?>  <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.android.contactmanager" android:versionCode="1" android:versionName="1.0"> <uses-sdk android:minSdkVersion="10" /> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/> <uses-permission android:name="android.permission.MANAGE_ACCOUNTS"/> <uses-permission android:name="android.permission.WRITE_OWNER_DATA"/> <uses-permission android:name="android.permission.CAMERA"/> <uses-permission android:name="android.permission.CALL_PHONE"/> <uses-permission android:name="android.permission.GET_ACCOUNTS" /> <uses-permission android:name="android.permission.READ_CONTACTS" /> <uses-permission android:name="android.permission.WRITE_CONTACTS" /> <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/> <uses-permission android:name="android.permission.INTERNET"/> <uses-permission android:name="android.permission.CAMERA"/> <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/> <uses-permission android:name="android.permission.GET_ACCOUNTS"/> <application android:label="@string/app_name" android:icon="@drawable/icon" android:allowBackup="true"> <activity android:name=".ContactManager" android:label="@string/app_name"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <activity android:name="ContactAdder" android:label="@string/addContactTitle"> </activity> <activity android:name=".SingleListContact" android:label="Contact Person Details"> </activity> </application> </manifest> The SingleListContact.java package com.example.android.contactmanager; import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.widget.TextView; public class SingleListContact extends Activity{ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); this.setContentView(R.layout.single_list_contact_view); TextView txtContact = (TextView) findViewById(R.id.contactList); Intent i = getIntent(); // getting attached intent data String contact = i.getStringExtra("contact"); // displaying selected product name txtContact.setText(contact); } } My ContactManager.java as below /* * Copyright (C) 2009 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.example.android.contactmanager; import android.app.Activity; import android.content.Intent; import android.database.Cursor; import android.net.Uri; import android.os.Bundle; import android.provider.ContactsContract; import android.util.Log; import android.view.View; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.Button; import android.widget.CheckBox; import android.widget.CompoundButton; import android.widget.CompoundButton.OnCheckedChangeListener; import android.widget.ListView; import android.widget.SimpleCursorAdapter; import android.widget.TextView; public final class ContactManager extends Activity implements OnItemClickListener { public static final String TAG = "ContactManager"; private Button mAddAccountButton; private ListView mContactList; private boolean mShowInvisible; //public BooleanObservable ShowInvisible = new BooleanObservable(false); private CheckBox mShowInvisibleControl; /** * Called when the activity is first created. Responsible for initializing the UI. */ @Override public void onCreate(Bundle savedInstanceState) { Log.v(TAG, "Activity State: onCreate()"); super.onCreate(savedInstanceState); setContentView(R.layout.contact_manager); // Obtain handles to UI objects mAddAccountButton = (Button) findViewById(R.id.addContactButton); mContactList = (ListView) findViewById(R.id.contactList); mShowInvisibleControl = (CheckBox) findViewById(R.id.showInvisible); // Initialise class properties mShowInvisible = false; mShowInvisibleControl.setChecked(mShowInvisible); // Register handler for UI elements mAddAccountButton.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { Log.d(TAG, "mAddAccountButton clicked"); launchContactAdder(); } }); mShowInvisibleControl.setOnCheckedChangeListener(new OnCheckedChangeListener() { public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { Log.d(TAG, "mShowInvisibleControl changed: " + isChecked); mShowInvisible = isChecked; populateContactList(); } }); mContactList = (ListView) findViewById(R.id.contactList); mContactList.setOnItemClickListener(this); // Populate the contact list populateContactList(); } /** * Populate the contact list based on account currently selected in the account spinner. */ private void populateContactList() { // Build adapter with contact entries Cursor cursor = getContacts(); String[] fields = new String[] { ContactsContract.Data.DISPLAY_NAME }; SimpleCursorAdapter adapter = new SimpleCursorAdapter(this, R.layout.contact_entry, cursor, fields, new int[] {R.id.contactEntryText}); mContactList.setAdapter(adapter); } /** * Obtains the contact list for the currently selected account. * * @return A cursor for for accessing the contact list. */ private Cursor getContacts() { // Run query Uri uri = ContactsContract.Contacts.CONTENT_URI; String[] projection = new String[] { ContactsContract.Contacts._ID, ContactsContract.Contacts.DISPLAY_NAME }; String selection = ContactsContract.Contacts.IN_VISIBLE_GROUP + " = '" + (mShowInvisible ? "0" : "1") + "'"; //String selection = ContactsContract.Contacts.IN_VISIBLE_GROUP + " = '" + (mShowInvisible.get() ? "0" : "1") + "'"; String[] selectionArgs = null; String sortOrder = ContactsContract.Contacts.DISPLAY_NAME + " COLLATE LOCALIZED ASC"; return this.managedQuery(uri, projection, selection, selectionArgs, sortOrder); } /** * Launches the ContactAdder activity to add a new contact to the selected account. */ protected void launchContactAdder() { Intent i = new Intent(this, ContactAdder.class); startActivity(i); } public void onItemClick(AdapterView<?> l, View v, int position, long id) { Log.i("TAG", "You clicked item " + id + " at position " + position); // Here you start the intent to show the contact details // selected item TextView tv=(TextView)v.findViewById(R.id.contactList); String allcontactlist = tv.getText().toString(); // Launching new Activity on selecting single List Item Intent i = new Intent(getApplicationContext(), SingleListContact.class); // sending data to new activity i.putExtra("Contact Person", allcontactlist); startActivity(i); } } contact_entry.xml <?xml version="1.0" encoding="utf-8"?>  <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical"> <ListView android:layout_width="wrap_content" android:id="@+id/contactList" android:layout_height="0dp" android:padding="10dp" android:textSize="200sp" android:layout_weight="10"/> <CheckBox android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/showInvisible" android:text="@string/showInvisible"/> <Button android:layout_width="fill_parent" android:layout_height="wrap_content" android:id="@+id/addContactButton" android:text="@string/addContactButtonLabel"/> </LinearLayout> Logcat result: 12-05 05:00:31.289: E/AndroidRuntime(642): FATAL EXCEPTION: main 12-05 05:00:31.289: E/AndroidRuntime(642): java.lang.NullPointerException 12-05 05:00:31.289: E/AndroidRuntime(642): at com.example.android.contactmanager.ContactManager.onItemClick(ContactManager.java:148) 12-05 05:00:31.289: E/AndroidRuntime(642): at android.widget.AdapterView.performItemClick(AdapterView.java:284) 12-05 05:00:31.289: E/AndroidRuntime(642): at android.widget.ListView.performItemClick(ListView.java:3513) 12-05 05:00:31.289: E/AndroidRuntime(642): at android.widget.AbsListView$PerformClick.run(AbsListView.java:1812) 12-05 05:00:31.289: E/AndroidRuntime(642): at android.os.Handler.handleCallback(Handler.java:587) 12-05 05:00:31.289: E/AndroidRuntime(642): at android.os.Handler.dispatchMessage(Handler.java:92) 12-05 05:00:31.289: E/AndroidRuntime(642): at android.os.Looper.loop(Looper.java:123) 12-05 05:00:31.289: E/AndroidRuntime(642): at android.app.ActivityThread.main(ActivityThread.java:3683) 12-05 05:00:31.289: E/AndroidRuntime(642): at java.lang.reflect.Method.invokeNative(Native Method) 12-05 05:00:31.289: E/AndroidRuntime(642): at java.lang.reflect.Method.invoke(Method.java:507) 12-05 05:00:31.289: E/AndroidRuntime(642): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 12-05 05:00:31.289: E/AndroidRuntime(642): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 12-05 05:00:31.289: E/AndroidRuntime(642): at dalvik.system.NativeStart.main(Native Method)

Read the article

Localization approach for XSLT + RESX in ASP.NET

- by frankadelic

I have an ASP.NET web app where the back end data (XML format) is transformed using XSLT, producing XHTML which is output into the page. Simplified code: XmlDocument xmlDoc = MyRepository.RetrieveXmlData(keyValue); XslCompiledTransform xsl = new XslCompiledTransform(); xsl.Load(pathToXsl, XsltSettings.TrustedXslt, null); StringWriter stringWriter = new StringWriter(); xsl.Transform(xmlDoc, null, stringWriter); myLiteral.Text = stringWriter.ToString(); Currently my XSL file contains the XHTML markup elements, as well as text labels, which are currently in English. for example: Title: <xsl:value-of select="title"/> Description: <xsl:value-of select="desc"/> I would like the text labels (Title and Description above) to be localized. I was thinking of using .NET resource files (.resx), but I don't know how the resx string resources would get pulled in to the XSLT when the transformation takes place. I would prefer not to have locale-specific copies of the XSLT file, since that means a lot of duplicate transformation logic. (NOTE: the XML data is already localized, so I don't need to change that)

Read the article

Padding is invalid and cannot be removed

- by Ajay

I have hosted an asp.net 2.0 site. Everyday, i am getting an error "Padding is invalid and cannot be removed" 2-3 times. Backend used is sql server 2005. the site is controlled via plesk 9.2 CP. Pooling is enabled with timeout as 120 Minutes, in IIS. Can it be the reason for this? I have not used any encryption except for the stored passwords(MD5) The error message is : " Base Exception = : Padding is invalid and cannot be removed. - Source : System.Web - TargetSite :Void ThrowError(System.Exception, System.String, System.String, Boolean)Message : Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster. " & System Log (Application) says " Event code: 4009 Event message: Viewstate verification failed. Reason: The viewstate supplied failed integrity check. Event detail code: 50203 ViewStateException information: Exception message: Invalid viewstate. Port: 31235 User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1) " I have hosted it in a dedicated server and not in a web farm. Will keeping a static machine key help resolve this issue? Please guide me on this.

Read the article

Help with iphone button pressed

- by StealthRT

I am trying to see which button was clicked on so I can preform the correct logic. This is the code for the buttons: UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(270, 423, 60, 60)]; [button addTarget:self action:@selector(buttonPressedAction:) forControlEvents:UIControlEventTouchUpInside]; [button setBackgroundImage:[[UIImage imageNamed:@"refreshicon.png"] stretchableImageWithLeftCapWidth:10.0 topCapHeight:0.0] forState:UIControlStateNormal]; UIButton *button2 = [[UIButton alloc] initWithFrame:CGRectMake(0, 423, 60, 60)]; [button2 addTarget:self action:@selector(buttonPressedAction:) forControlEvents:UIControlEventTouchUpInside]; [button2 setBackgroundImage:[[UIImage imageNamed:@"login.png"] stretchableImageWithLeftCapWidth:10.0 topCapHeight:0.0] forState:UIControlStateNormal]; [self.navigationController.view addSubview:button]; [self.navigationController.view addSubview:button2]; And this is how I call the buttonPressedAction: - (void)buttonPressedAction:(id)sender { NSLog(@"%@", [sender value]); isRefreshing = TRUE; [self loadTheXML]; [self.tableView reloadData]; } But when I use NSLog to see what the sender value is, it crashes. Any advice for what's happening and how to correct it?

Read the article

How to explain to someone that a data structure should not draw itself, explaining separation of con

- by leeand00

I have another programmer who I'm trying to explain why it is that a UI component should not also be a data-structure. For instance say that you get a data-structure that contains a record-set from the "database", and you wish to display that record-set in a UI component within your application. According to this programmer (who will remain nameless, he's young and I'm teaching him...), we should subclass the data-structure into a class that will draw the UI component within our application!!!!!! And thus according to this logic, the record-set should manage the drawing of the UI. **Head Desk*** I know that asking a record-set to draw itself is wrong, because, if you wish to render the same data-structure on more than one type of component on your UI, you are going to have a real mess on your hands; you'll need to extend yet another class for each and every UI component that you render from the base-class of your record-set; I am well aware of the "cleanliness" of the of the MVC pattern (and by that what I really mean is you don't confuse your data (the Model) with your UI (the view) or the actions that take place on the data (the Controller more or less...okay not really the API should really handle that...and the Controller should just make as few calls to it as it can, telling it which view to render)) But it's certainly alot cleaner than using data-structures to render UI components! Is there any other advice I could send his way other than the example above? I understand that when you first learn OOP you go through "a stage" where you where just want to extend everything. Followed by a stage when you think that Design Patterns are the solution every single problem...which isn't entirely correct either...thanks Jeff. Is there a way that I can gently nudge this kid in the right direction? Do you have any more examples that might help explain my point to him?

Read the article

Optimal Serialization of Primitive Types

- by Greg Dean

We are beginning to roll out more and more WAN deployments of our product (.Net fat client w/ IIS hosted Remoting backend). Because of this we are trying to reduce the size of the data on the wire. We have overridden the default serialization by implementing ISerializable (similar to this), we are seeing anywhere from 12% to 50% gains. Most of our efforts focus on optimizing arrays of primitive types. I would like to know if anyone knows of any fancy way of serializing primitive types, beyond the obvious? For example today we serialize an array of ints as follows: [4-bytes (array length)][4-bytes][4-bytes] Can anyone do significantly better? The most obvious example of a significant improvement, for boolean arrays, is putting 8 bools in each byte, which we already do. Note: Saving 7 bits per bool may seem like a waste of time, but when you are dealing with large magnitudes of data (which we are), it adds up very fast. Note: We want to avoid general compression algorithms because of the latency associated with it. Remoting only supports buffered requests/responses(no chunked encoding). I realize there is a fine line between compression and optimal serialization, but our tests indicate we can afford very specific serialization optimizations at very little cost in latency. Whereas reprocessing the entire buffered response into new compressed buffer is too expensive.

Read the article

Publishing my Website to my Local Disk Causes Exceptions to show Paths including my Local Disk

- by coffeeaddict

I've published my website many times. But didn't think about this though until I came across this issue. So I decided to publish my WAP project to a local folder on my C drive first. Then used FTP to upload it to my shared host on discountasp.net. I noticed during runtime that the stack trace was referencing that local folder still and erroring out. Anyone know what config settings are affected when publishing? Obviously something is still pointing to my local C drive and I've searched my entire solution and don't see why. Here's the runtime error I get when my code tries to run in discountasp.net's web server Cannot write into the public directory - check permissions 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: ScrewTurn.Wiki.PluginFramework.InvalidConfigurationException: Cannot write into the public directory - check permissions Source Error: An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below. Stack Trace: [InvalidConfigurationException: Cannot write into the public directory - check permissions] ScrewTurn.Wiki.SettingsStorageProvider.Init(IHostV30 host, String config) in C:\www\Wiki\Screwturn3_0_2_509\Core\SettingsStorageProvider.cs:90 ScrewTurn.Wiki.StartupTools.Startup() in C:\www\Wiki\Screwturn3_0_2_509\Core\StartupTools.cs:69 ScrewTurn.Wiki.Global.Application_BeginRequest(Object sender, EventArgs e) in C:\www\Wiki\Screwturn3_0_2_509\WebApplication\Global.asax.cs:29 System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +68 System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +75 Discountasp says it's not a permission issue but obviously it is. I think /Wiki should work...but it's not. Here's my site viewed in FTP on discountasp.net's server:

Read the article

OsmDroid show blank screen with blocks

- by Lennie

Am trying to use OsmDroid with MapQuest maps downloaded from Mobile Atlas Creator. I followed all the instructions to generate the map tiles, upload them to the SDcard etc but when I run this on the device I get a screen with a bunch of empty boxes... What am I doing wrong? > @Override > public void onCreate(Bundle savedInstanceState) { > super.onCreate(savedInstanceState); > setContentView(R.layout.osm_map); > mapView = (MapView) findViewById(R.id.mapview); > mapView.setTileSource(TileSourceFactory.MAPQUESTOSM); > mapView.setBuiltInZoomControls(true); > mapView.setUseDataConnection(false); > mapController = mapView.getController(); > mapController.setZoom(15); > } > protected boolean isRouteDisplayed() { > // TODO Auto-generated method stub > return false; > }

Read the article

Simple Java calculator

- by Kevin Duke

Firstly this is not a homework question. I am practicing my knowledge on java. I figured a good way to do this is to write a simple program without help. Unfortunately, my compiler is telling me errors I don't know how to fix. Without changing much logic and code, could someone kindly point out where some of my errors are? Thanks import java.lang.*; import java.util.*; public class Calculator { private int solution; private int x; private int y; private char operators; public Calculator() { solution = 0; Scanner operators = new Scanner(System.in); Scanner operands = new Scanner(System.in); } public int addition(int x, int y) { return x + y; } public int subtraction(int x, int y) { return x - y; } public int multiplication(int x, int y) { return x * y; } public int division(int x, int y) { solution = x / y; return solution; } public void main (String[] args) { System.out.println("What operation? ('+', '-', '*', '/')"); System.out.println("Insert 2 numbers to be subtracted"); System.out.println("operand 1: "); x = operands; System.out.println("operand 2: "); y = operands.next(); switch(operators) { case('+'): addition(operands); operands.next(); break; case('-'): subtraction(operands); operands.next(); break; case('*'): multiplication(operands); operands.next(); break; case('/'): division(operands); operands.next(); break; } } }

Read the article

What is the relationship between Turing Machine & Modern Computer ? [closed]

- by smwikipedia

I heard a lot that modern computers are based on Turing machine. I just cannot build a bridge between a conceptual Turing Machine and a modern computer. Could someone help me build this bridge? Below is my current understanding. I think the computer is a big general-purpose Turing machine. Each program we write is a small specific-purpose Turing machine. The classical Turing machine do its job based on the input and its current state inside and so do our programs. Let's take a running program (a process) as an example. We know that in the process's address space, there's areas for stack, heap, and code. A classical Turing machine doesn't have the ability to remember many things, so we borrow the concept of stack from the push-down automaton. The heap and stack areas contains the state of our specific-purpose Turing machine (our program). The code area represents the logic of this small Turing machine. And various I/O devices supply input to this Turing machine.

Read the article

How can I filter a JTable?

- by Jonas

I would like to filter a JTable, but I don't understand how I can do it. I have read How to Use Tables - Sorting and Filtering and I have tried with the code below, but with that filter, no rows at all is shown in my table. And I don't understand what column it is filtered on. private void myFilter() { RowFilter<MyModel, Object> rf = null; try { rf = RowFilter.regexFilter(filterFld.getText(), 0); } catch (java.util.regex.PatternSyntaxException e) { return; } sorter.setRowFilter(rf); } MyModel has three columns, the first two are strings and the last column is of type Integer. How can I apply the filter above, consider the text in filterFld.getText() and only filter the rows where the text is matched on the second column? I would like to show all rows that starts with the text specified by filterFld.getText(). I.e. if the text is APP then the JTable should contain the rows where the second column starts with APPLE, APPLICATION but not the rows where the second column is CAR, ORANGE. I have also tried with this filter: RowFilter<MyModel, Integer> itemFilter = new RowFilter<MyModel, Integer>(){ public boolean include(Entry<? extends MyModel, ? extends Integer> entry){ MyModel model = entry.getModel(); MyItem item = model.getRecord(entry.getIdentifier()); if (item.getSecondColumn().startsWith("APP")) { return true; } else { return false; } } }; How can I write a filter that is filtering the JTable on the second column, specified by my textfield?

Read the article

How to make Stack.Pop threadsafe

- by user260197

I am using the BlockingQueue code posted in this question, but realized I needed to use a Stack instead of a Queue given how my program runs. I converted it to use a Stack and renamed the class as needed. For performance I removed locking in Push, since my producer code is single threaded. My problem is how can thread working on the (now) thread safe Stack know when it is empty. Even if I add another thread safe wrapper around Count that locks on the underlying collection like Push and Pop do, I still run into the race condition that access Count and then Pop are not atomic. Possible solutions as I see them (which is preferred and am I missing any that would work better?): Consumer threads catch the InvalidOperationException thrown by Pop(). Pop() return a nullptr when _stack-Count == 0, however C++-CLI does not have the default() operator ala C#. Pop() returns a boolean and uses an output parameter to return the popped element. Here is the code I am using right now: generic <typename T> public ref class ThreadSafeStack { public: ThreadSafeStack() { _stack = gcnew Collections::Generic::Stack<T>(); } public: void Push(T element) { _stack->Push(element); } T Pop(void) { System::Threading::Monitor::Enter(_stack); try { return _stack->Pop(); } finally { System::Threading::Monitor::Exit(_stack); } } public: property int Count { int get(void) { System::Threading::Monitor::Enter(_stack); try { return _stack->Count; } finally { System::Threading::Monitor::Exit(_stack); } } } private: Collections::Generic::Stack<T> ^_stack; };

Read the article

Force full garbage collection when memory occupation goes beyond a certain threshold

- by Silvio Donnini

I have a server application that, in rare occasions, can allocate large chunks of memory. It's not a memory leak, as these chunks can be claimed back by the garbage collector by executing a full garbage collection. Normal garbage collection frees amounts of memory that are too small: it is not adequate in this context. The garbage collector executes these full GCs when it deems appropriate, namely when the memory footprint of the application nears the allotted maximum specified with -Xmx. That would be ok, if it wasn't for the fact that these problematic memory allocations come in bursts, and can cause OutOfMemoryErrors due to the fact that the jvm is not able to perform a GC quickly enough to free the required memory. If I manually call System.gc() beforehand, I can prevent this situation. Anyway, I'd prefer not having to monitor my jvm's memory allocation myself (or insert memory management into my application's logic); it would be nice if there was a way to run the virtual machine with a memory threshold, over which full GCs would be executed automatically, in order to release very early the memory I'm going to need. Long story short: I need a way (a command line option?) to configure the jvm in order to release early a good amount of memory (i.e. perform a full GC) when memory occupation reaches a certain threshold, I don't care if this slows my application down every once in a while. All I've found till now are ways to modify the size of the generations, but that's not what I need (at least not directly). I'd appreciate your suggestions, Silvio P.S. I'm working on a way to avoid large allocations, but it could require a long time and meanwhile my app needs a little stability

Read the article

Parsing a string, Grammar file.

- by defn

How would I separate the below string into its parts. What I need to separate is each < Word including the angle brackets from the rest of the string. So in the below case I would end up with several strings 1. "I have to break up with you because " 2. "< reason " (without the spaces) 3. " . But Let's still " 4. "< disclaimer " 5. " ." I have to break up with you because <reason> . But let's still <disclaimer> . below is what I currently have (its ugly...) boolean complete = false; int begin = 0; int end = 0; while (complete == false) { if (s.charAt(end) == '<'){ stack.add(new Terminal(s.substring(begin, end))); begin = end; } else if (s.charAt(end) == '>') { stack.add(new NonTerminal(s.substring(begin, end))); begin = end; end++; } else if (end == s.length()){ if (isTerminal(getSubstring(s, begin, end))){ stack.add(new Terminal(s.substring(begin, end))); } else { stack.add(new NonTerminal(s.substring(begin, end))); } complete = true; } end++;

Read the article

WPF - How to properly reference a class from XAML

- by Andy T

OK, this is a super super noob question, one that I'm almost embarrassed to ask... I want to reference a class in my XAML file. It's a DataTemplateSelector for selecting the right edit template for a DataGrid column. Anyway, I've written the class into my code behind, added the local namespace to the top of top of the XAML, but when I try to reference the class from the XAML, it tells me the class does not exist in the local namespace. I must be missing something really really simple but I just can't understand it... Here's my code. XAML: <Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:tk="http://schemas.microsoft.com/wpf/2008/toolkit" xmlns:local="clr-namespace:CustomFields" xmlns:col="clr-namespace:System.Collections;assembly=mscorlib" xmlns:sys="clr-namespace:System;assembly=mscorlib" x:Class="CustomFields.MainWindow" x:Name="Window" Title="Define Custom Fields" Width="425" Height="400" MinWidth="425" MinHeight="400"> <Window.Resources> <ResourceDictionary> <local:RangeValuesEditTemplateSelector> blah blah blah... </local:RangeValuesEditTemplateSelector> </ResourceDictionary> </Window.Resources> C#: namespace CustomFields { /// /// Interaction logic for MainWindow.xaml /// public partial class MainWindow : Window { public MainWindow() { this.InitializeComponent(); // Insert code required on object creation below this point. } } public class RangeValuesEditTemplateSelector : DataTemplateSelector { public RangeValuesEditTemplateSelector(){ MessageBox.Show("hello"); } } } Any ideas what I'm doing wrong? I thought this should be simple as 1-2-3... Thanks! AT

Search Results

Search found 8776 results on 352 pages for 'boolean logic'.

Page 258/352 | < Previous Page | 254 255 256 257 258 259 260 261 262 263 264 265 | Next Page >

- by Matt Ruwe

- by stimpy77

- by mightyhal

- by iamrohitbanga

- by Tom

- by Nathan

- by James Cooper

- by carpediem

- by zurna

- by zurna

- by Sean Tan

- by frankadelic

- by Ajay

- by StealthRT

- by leeand00

- by Greg Dean

- by coffeeaddict

- by Lennie

- by Kevin Duke

- by smwikipedia

- by Jonas

- by user260197

- by Silvio Donnini

- by defn

- by Andy T

< Previous Page | 254 255 256 257 258 259 260 261 262 263 264 265 | Next Page >