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  • Does Google sometimes ignore "special" characters, possibly depending on your location or font type settings? [closed]

    - by RLH
    TLDR Google tends to ignore special characters in my search strings. Is there anything that I can do about it and is it, possibly, happening because Google makes certain assumptions based off of my default text-encoding settings and my location? I just posted this question over at StackOverflow. I had found a C preprocessor that I'd never seen before. As I should have done, I Googled it and tried to find out further information. I attempted various search terms which were all variations of "C Operator ##" (some times with and some times without the double-quotes.) Google didn't bring back anything of use so I posted my question on SO. As you can see from the comments, someone mentioned a search string (ironically one which I did try to search) and stated that I could have even hit the "I'm feeling lucky" button and have gotten my answer. The problem is I did search that, and the results that I received were far more basic and even after following the top results and searching the resulting pages, I could find nothing referencing the string "##". I'm not posting this question to complain but it does provide an empirical example of something I've seen before that really bugs me-- Google often ignores special characters in my search strings and the results are often useless. As a developer I often need to search for string values containing non-alphanumeric characters. Some characters (like the underscore or hyphen) can be used without trouble. However, other characters (such as the ampersand, carat, tilde and pound sign) are often ignored in my query strings. Is there a way to prevent this from happening so that I can get meaningful results from Google? NOTE I stay logged into Google and I live in the US. I wonder if Google detects some form of text-encoding setting or derives my results based off of certain, localized text-based assumptions. Regardless, I would like to for Google to search for what I give it. Is there anything that I can do to improve my results?

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  • Which type of motherboard i should buy and why?

    - by metal gear solid
    If budged is not a problem. I just need best performance with less power consumption. I can purchase any cabinet , power supply and Motherboard. Is Power supply has any relation with Form factor? Is the size of motherboard and number of Slots only difference between all form factors? Is there any differences among form factors, related to performance of motherboard? Is bigger in Size (ATX) motherboard always better? Is it so smaller in Size motherboard will consume less power? What are pros and cons of each Form factor? What there are so many Form factor were created?

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  • How do I set a service startup type to be 'Automatic (delayed)' using GPO?

    - by growse
    A Windows service has 4 different startup types that can be configured: Automatic, Automatic (delayed), Manual and Disabled. I have a service running on a combination of Windows 7 and Server 2008 R2 Desktops that I need to set as 'Automatic (delayed)' using a GPO setting, but from what I can see in the GPO editor, the delayed option is missing: Have I missed something obvious, or is this a rather basic omission from Microsoft?

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  • How do I rsync an entire folder based on the existence of a specific file type in that folder

    - by inquam
    I have a server set up that receives movies to a folder. I then serve these movies using DLNA. But in the initial folder where they end up all kind of files end up. Pictures, music, documents etc. I thought I'd fix this by running the following script inside that folder rsync -rvt --include='*/' --include='*.avi' --include='*.mkv' --exclude='*' . ../Movies/ This works and scans the given folder and moves all the found movies of the given extension types to the Movies folder. But I wonder if there is anyway to tell rsync to if a folder if found that includes a movie of the given extension types, sync the entire folder. Including other files such as .srt. This is to make it easier for me to get subtitles moved along with the movie. I have a solution figured out via a script made in php (yea, I actually do most of my scripting in linux using php... just a habbit that stuck a long time ago). But if rsync can handle it from the start that would be super. Also, I have noticed that this line of rsync actually copies all the root folders in the given folder. If no movie is in the folder it will create an empty folder. How do I prevent rsync from doing this... and saving me the trouble of deleting all folder in Movies that are empty.

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  • permission not to change on eth0 file?

    - by user133916
    I am logged in as a root user i want to edit my /etc/sysconfig/network-scripts/ifcfg-eth0 file when i edit this showing -- INSERT -- W10: Warning: Changing a readonly file while i have logged in as root user my mount showing [root@s1202 ~]# mount rootfs on / type rootfs (rw) /dev/root on / type ext3 (ro,data=ordered) /dev on /dev type tmpfs (rw) /proc on /proc type proc (rw) /sys on /sys type sysfs (rw) /proc/bus/usb on /proc/bus/usb type usbfs (rw)

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  • Is there a way to get x-mouse-type scrolling under the cursor for child windows within one program window?

    - by eigor40
    I've been messing with X-mouse setups, to enable scrolling for whatever is under the cursor, regardless of whether it has the focus or not. I've found several ways to get this to work between various 'parent' windows (Win7's built-in mouse options, WizMouse, etc), but I've found nothing that will do the same thing with (for example) several child windows with spreadsheets, open at the same time in one parent Excel window. I have the spreadsheets set up so that two are visible in the window at the same time, but I always have to click on either one to scroll it up and down. I'd love to be able to scroll these just by moving the mouse and doing the scroll, without the extra focus-change-click. I am not a big fan of running separate parent windows for each spreadsheet, which I realize would be something of a workaround. I'd rather keep the single parent Excel window, but still have X-mouse functionality within it. Anyone know of any way to achieve this? I'd call it "XMouse for Child Windows".

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  • Can you change the type of Active Directory Password Complexity to be different than MS version?

    - by littlegeek
    Here it states that the policy must adhere to Passwords must meet complexity requirements determines whether password complexity is enforced. If this setting is enabled, user passwords meet the following requirements: The password is at least six characters long. The password contains characters from at least three of the following five categories: English uppercase characters (A - Z) English lowercase characters (a - z) Base 10 digits (0 - 9) Non-alphanumeric (For example: !, $, #, or %) Unicode characters The password does not contain three or more characters from the user's account name. They only setting is to ENABLE or DISABLE this feature. I was wondering if there is a way to change this policy? IF so where?

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  • How can Icheck how much data has been transfered in a particular remote computer in my LAN?

    - by oDx
    I am the system administrator. I am suspecting some unwanted data transfers in some of the computers under my lan. This also effects the overall performance of the network. Is there anyway by which i can check the transfered data over a particular interval. I am not supposed to install any applications on any other computers than mine. I have the router access. I can use tools like ettercap dsniff wireshark etc.

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  • Which type of motherboard i should by and why?

    - by metal gear solid
    If budged is not matter. I just need best performance with less power consumption. I can purchase any cabinet , power supply and Motherboard. Is Power supply has any relation with Form factor? Is the size of motherboard and number of Slots only difference between all form factors? Is there any difference related to performance of motherboard? Is bigger in Size (ATX) motherboard always better?

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  • How can I check how much data has been transfered in a particular remote computer in my LAN?

    - by oDx
    I am the system administrator. I am suspecting some unwanted data transfers in some of the computers under my lan. This also effects the overall performance of the network. Is there anyway by which i can check the transfered data over a particular interval. I am not supposed to install any applications on any other computers than mine. I have the router access. I can use tools like ettercap dsniff wireshark etc.

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  • Which type of Form factor (motherboard) i should buy and why?

    - by metal gear solid
    If budged is not a problem. I just need best performance with less power consumption. I can purchase any cabinet , power supply and Motherboard. Is Power supply has any relation with Form factor, should i purchase PSU according to Form factor of motherboard? Is the size of motherboard and number of Slots only difference between all form factors? Is there any differences among form factors, related to performance of motherboard? Is bigger in Size (ATX) motherboard always better? Is it so smaller in Size motherboard will consume less power? What are pros and cons of each Form factor? What there are so many Form factor were created?

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  • What is the best way/tool to analyze raw data(network stats) from Simulation?

    - by user90500
    After running a simulation(using a simulator(QualNet)) of a simulated network I end up with ip stats stored in a database, I then extract the data to a csv file So now I have 750mb of raw network stats(time stamp, packet id, source ip, source port, protocol, etc). What are the common ways of analyzing large amounts of data like above, if you want to know things like packet loss, throughput, delay, congestion, etc.

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  • multiple-inheritance substitution

    - by Luigi
    I want to write a module (framework specific), that would wrap and extend Facebook PHP-sdk (https://github.com/facebook/php-sdk/). My problem is - how to organize classes, in a nice way. So getting into details - Facebook PHP-sdk consists of two classes: BaseFacebook - abstract class with all the stuff sdk does Facebook - extends BaseFacebook, and implements parent abstract persistance-related methods with default session usage Now I have some functionality to add: Facebook class substitution, integrated with framework session class shorthand methods, that run api calls, I use mostly (through BaseFacebook::api()), authorization methods, so i don't have to rewrite this logic every time, configuration, sucked up from framework classes, insted of passed as params caching, integrated with framework cache module I know something has gone very wrong, because I have too much inheritance that doesn't look very normal.Wrapping everything in one "complex extension" class also seems too much. I think I should have few working togheter classes - but i get into problems like: if cache class doesn't really extend and override BaseFacebook::api() method - shorthand and authentication classes won't be able to use the caching. Maybe some kind of a pattern would be right in here? How would you organize these classes and their dependencies? EDIT 04.07.2012 Bits of code, related to the topic: This is how the base class of Facebook PHP-sdk: abstract class BaseFacebook { // ... some methods public function api(/* polymorphic */) { // ... method, that makes api calls } public function getUser() { // ... tries to get user id from session } // ... other methods abstract protected function setPersistentData($key, $value); abstract protected function getPersistentData($key, $default = false); // ... few more abstract methods } Normaly Facebook class extends it, and impelements those abstract methods. I replaced it with my substitude - Facebook_Session class: class Facebook_Session extends BaseFacebook { protected function setPersistentData($key, $value) { // ... method body } protected function getPersistentData($key, $default = false) { // ... method body } // ... implementation of other abstract functions from BaseFacebook } Ok, then I extend this more with shorthand methods and configuration variables: class Facebook_Custom extends Facebook_Session { public funtion __construct() { // ... call parent's constructor with parameters from framework config } public function api_batch() { // ... a wrapper for parent's api() method return $this->api('/?batch=' . json_encode($calls), 'POST'); } public function redirect_to_auth_dialog() { // method body } // ... more methods like this, for common queries / authorization } I'm not sure, if this isn't too much for a single class ( authorization / shorthand methods / configuration). Then there comes another extending layer - cache: class Facebook_Cache extends Facebook_Custom { public function api() { $cache_file_identifier = $this->getUser(); if(/* cache_file_identifier is not null and found a valid file with cached query result */) { // return the result } else { try { // call Facebook_Custom::api, cache and return the result } catch(FacebookApiException $e) { // if Access Token is expired force refreshing it parent::redirect_to_auth_dialog(); } } } // .. some other stuff related to caching } Now this pretty much works. New instance of Facebook_Cache gives me all the functionality. Shorthand methods from Facebook_Custom use caching, because Facebook_Cache overwrited api() method. But here is what is bothering me: I think it's too much inheritance. It's all very tight coupled - like look how i had to specify 'Facebook_Custom::api' instead of 'parent:api', to avoid api() method loop on Facebook_Cache class extending. Overall mess and ugliness. So again, this works but I'm just asking about patterns / ways of doing this in a cleaner and smarter way.

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  • Manipulate multiple check boxes by ID using unobtrusive java script?

    - by Dean
    I want to be able to select multiple check boxes onmouseover, but instead of applying onmouseover to every individual box, I've been trying to work out how to do so by manipulating check boxes by ID instead, although I'm not sure where to go from using getElementById,. So instead of what you see below. <html> <head> <script> var Toggle = true; var Highlight=false; function handleKeyPress(evt) { var nbr; if (window.Event) nbr = evt.which; else nbr = event.keyCode; if(nbr==16)Highlight=true; return true; } function MakeFalse(){Highlight=false;} function SelectIt(X){ if(X.checked && Toggle)X.checked=false; else X.checked=true; } function ChangeText() { var test1 = document.getElementById("1"); test1.innerHTML = "onmouseover=SelectIt(this)" } </script> </head> <body> <form name="A"> <input type="checkbox" name="C1" onmouseover="SelectIt(this)" id="1"><br> <input type="checkbox" name="C2" onmouseover="SelectIt(this)" id="2"><br> <input type="checkbox" name="C3" onmouseover="SelectIt(this)" id="3"><br> <input type="checkbox" name="C4" onmouseover="SelectIt(this)" checked="" disabled="disabled" id="4"><br> <input type="checkbox" name="C5" onmouseover="SelectIt(this)" id="5"><br> <input type="checkbox" name="C6" onmouseover="SelectIt(this)" id="6"><br> <input type="checkbox" name="C7" onmouseover="SelectIt(this)" id="7"><br> <input type="checkbox" name="C8" onmouseover="SelectIt(this)" id="8"><br> </form> </body> </html> I want to be able to apply the onmousover effect to an array of check boxes like this <form name="A"> <input type="checkbox" name="C1" id="1"><br> <input type="checkbox" name="C2" id="2"><br> <input type="checkbox" name="C3" id="3"><br> <input type="checkbox" name="C4" checked="" disabled="disabled" id="4"><br> <input type="checkbox" name="C5" id="5"><br> <input type="checkbox" name="C6" id="6"><br> <input type="checkbox" name="C7" id="7"><br> <input type="checkbox" name="C8" id="8"><br> </form> After trying the search feature of stackoverflow.com and looking around on Google I haven't been able to a find a solution that makes sense to me thus far, although I'm still in the process of learning so I fear I might be trying to do something too advanced for my level of knowledge.

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  • innter.HTML not working after submit button is clicked

    - by user1781453
    I am trying to get the innerHTML to change to what is in the end of the function "calculate" but nothing happens once I hit submit. Here is my code: Pizza Order Form .outp {border-style:solid;background-color:white; border-color:red;padding:1em; border-width: .5em;} .notes {font-size:smaller;font-style:italic;} p {margin-left: 15%; width: 65%;} textarea {resize : none;} </style> function calculate(){ var type; var newline=""; var sum=0; var toppings=""; if( document.getElementById("small").checked==true){ type="Small Pizza"; sum+=4; } if( document.getElementById("medium").checked==true){ type="Medium Pizza"; sum+=6; } if( document.getElementById("large").checked==true){ type="Large Pizza"; sum+=8; } if( document.getElementById("pepperoni").checked==true){ toppings=toppings+"pepperoni, "; sum+=0.75; } if( document.getElementById("olives").checked==true){ toppings=toppings+"olives, "; sum+=0.6; } if( document.getElementById("sausage").checked==true){ toppings=toppings+"sausage, "; sum+=0.75; } if( document.getElementById("peppers").checked==true){ toppings=toppings+"peppers, "; sum+=0.5; } if( document.getElementById("onions").checked==true){ toppings=toppings+"onions, "; sum+=0.5; } if( document.getElementById("cheese").checked==true){ toppings=toppings+"Cheese Only, "; } var length = toppings.length; toppings = toppings.slice(0,length-2); document.getElementById("opta").innerHTML = type+newline+"Toppings:"+newline+toppings+newline+"Price - $"+sum; } Joe's Pizza Palace On-line Order Form <p id = "op" class = "outp" > <b /> Select the size Pizza you want: &nbsp;&nbsp; <input type="radio" name = "size" id="small" value = "small"> Small - $4.00 <b /> <input type="radio" name = "size" id="medium" value = "medium"> Medium - $6.00 <b /> <input type="radio" name = "size" id="large" value = "large"> Large - $8.00 <b /> </p> <p id = "op1" class = "outp" > <b /> Select the toppings: &nbsp;&nbsp; <input type="checkbox" name = "size" id="pepperoni" value = "pepperoni"> Pepperoni ($0.75) <b /> <input type="checkbox" name = "size" id="olives" value = "olives"> Olives ($0.60) <b /> <input type="checkbox" name = "size" id="sausage" value = "sausage"> Sausage ($0.75) <b /> <br /> <input type="checkbox" name = "size" id="peppers" value = "peppers"> Peppers ($0.50) <b /> <input type="checkbox" name = "size" id="onions" value = "onions"> Onions ($0.50) <b /> <input type="checkbox" name = "size" id="cheese" value = "cheese"> Cheese Only <b /> To obtain the price of your order click on the price button below: <br /><br /> <input type="button" align = "left" onclick="calculate();" value="Price (Submit Button)"/> <input type="reset" align = "left" value="Clear Form"/> <br /><br /> <textarea class="outp3" id="opta" style="border-color:black;" rows="6" cols="40" > </textarea>

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  • With NHibernate, how can I add a child object when updating a parent object?

    - by BMZ
    I have a simple Parent/Child relationship between a Person object and an Address object. The Person object exists in the DB. After doing a Get on the Person, I add a new Address object to the Address sub-object list of the parent, and do some other updates to the Person object. Finally, I do an Update on the Person object. With a SQL trace window, I can see the update to the Person object to the Person table and the Insert of the Address record to the Address table. The issue is that, after the update is performed, the AddressId (primary key on the Address object) is still set to 0, which is what it defaults to when you first initialize the Address object. I have verified that when I do an Add, this value is set correctly. Is this a known issue when trying to add sub-objects as part of an NHibernate UPDATE? Sample code and mapping files are below Thanks <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"> <class name="BusinessEntities.Wellness.Person,BusinessEntities.Wellness" table="Person" lazy="true" dynamic-insert="true" dynamic-update="false"> <id name="Personid" column="PersonID" type="int"> <generator class="native" /> </id> <version type="binary" generated="always" name="RecordVersion" column="`RecordVersion`"/> <property type="int" not-null="true" name="Customerid" column="`CustomerID`" /> <property type="AnsiString" not-null="true" length="9" name="Ssn" column="`SSN`" /> <property type="AnsiString" not-null="true" length="30" name="FirstName" column="`FirstName`" /> <property type="AnsiString" not-null="true" length="35" name="LastName" column="`LastName`" /> <property type="AnsiString" length="1" name="MiddleInitial" column="`MiddleInitial`" /> <property type="DateTime" name="DateOfBirth" column="`DateOfBirth`" /> <bag name="PersonAddresses" inverse="true" lazy="true" cascade="all"> <key column="PersonID" /> <one-to-many class="BusinessEntities.Wellness.PersonAddress,BusinessEntities.Wellness" / </bag> </class> </hibernate-mapping> <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"> <class name="BusinessEntities.Wellness.PersonAddress,BusinessEntities.Wellness" table="PersonAddress" lazy="true" dynamic-insert="true" dynamic-update="false"> <id name="PersonAddressId" column="PersonAddressID" type="int"> <generator class="native" /> </id> <version type="binary" generated="always" name="RecordVersion" column="`RecordVersion`" /> <property type="AnsiString" not-null="true" length="1" name="AddressTypeid" column="`AddressTypeID`" /> <property type="AnsiString" not-null="true" length="60" name="AddressLine1" column="`AddressLine1`" /> <property type="AnsiString" length="60" name="AddressLine2" column="`AddressLine2`" /> <property type="AnsiString" length="60" name="City" column="`City`" /> <property type="AnsiString" length="2" name="UsStateId" column="`USStateID`" /> <property type="AnsiString" length="5" name="UsPostalCodeId" column="`USPostalCodeID`" /> <many-to-one name="Person" cascade="none" column="PersonID" /> </class> </hibernate-mapping> Person newPerson = new Person(); newPerson.PersonName = "John Doe"; newPerson.SSN = "111111111"; newPerson.CreatedBy = "RJC"; newPerson.CreatedDate = DateTime.Today; personDao.AddPerson(newPerson); Person updatePerson = personDao.GetPerson(newPerson.PersonId); updatePerson.PersonAddresses = new List<PersonAddress>(); PersonAddress addr = new PersonAddress(); addr.AddressLine1 = "1 Main St"; addr.City = "Boston"; addr.State = "MA"; addr.Zip = "12345"; updatePerson.PersonAddresses.Add(addr); personDao.UpdatePerson(updatePerson); int addressID = updatePerson.PersonAddresses[0].AddressId;

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  • Is it safe to assert a functions return type?

    - by wb
    This question is related to this question. I have several models stored in a collection. I loop through the collection and validate each field. Based on the input, a field can either be successful, have an error or a warning. Is it safe to unit test each decorator and assert that the type of object returned is what you would expect based on the given input? I could perhaps see this being an issue for a language with function return types since my validation function can return one of 3 types. This is the code I'm fiddling with: <!-- #include file = "../lib/Collection.asp" --> <style type="text/css"> td { padding: 4px; } td.error { background: #F00F00; } td.warning { background: #FC0; } </style> <% Class UserModel Private m_Name Private m_Age Private m_Height Public Property Let Name(value) m_Name = value End Property Public Property Get Name() Name = m_Name End Property Public Property Let Age(value) m_Age = value End Property Public Property Get Age() Age = m_Age End Property Public Property Let Height(value) m_Height = value End Property Public Property Get Height() Height = m_Height End Property End Class Class NameValidation Private m_Name Public Function Init(name) m_Name = name End Function Public Function Validate() Dim validationObject If Len(m_Name) < 5 Then Set validationObject = New ValidationError Else Set validationObject = New ValidationSuccess End If validationObject.CellValue = m_Name Set Validate = validationObject End Function End Class Class AgeValidation Private m_Age Public Function Init(age) m_Age = age End Function Public Function Validate() Dim validationObject If m_Age < 18 Then Set validationObject = New ValidationError ElseIf m_Age = 18 Then Set validationObject = New ValidationWarning Else Set validationObject = New ValidationSuccess End If validationObject.CellValue = m_Age Set Validate = validationObject End Function End Class Class HeightValidation Private m_Height Public Function Init(height) m_Height = height End Function Public Function Validate() Dim validationObject If m_Height > 400 Then Set validationObject = New ValidationError ElseIf m_Height = 324 Then Set validationObject = New ValidationWarning Else Set validationObject = New ValidationSuccess End If validationObject.CellValue = m_Height Set Validate = validationObject End Function End Class Class ValidationError Private m_CSSClass Private m_CellValue Public Property Get CSSClass() CSSClass = "error" End Property Public Property Let CellValue(value) m_CellValue = value End Property Public Property Get CellValue() CellValue = m_CellValue End Property End Class Class ValidationWarning Private m_CSSClass Private m_CellValue Public Property Get CSSClass() CSSClass = "warning" End Property Public Property Let CellValue(value) m_CellValue = value End Property Public Property Get CellValue() CellValue = m_CellValue End Property End Class Class ValidationSuccess Private m_CSSClass Private m_CellValue Public Property Get CSSClass() CSSClass = "" End Property Public Property Let CellValue(value) m_CellValue = value End Property Public Property Get CellValue() CellValue = m_CellValue End Property End Class Class ModelValidator Public Function ValidateModel(model) Dim modelValidation : Set modelValidation = New CollectionClass ' Validate name Dim name : Set name = New NameValidation name.Init model.Name modelValidation.Add name ' Validate age Dim age : Set age = New AgeValidation age.Init model.Age modelValidation.Add age ' Validate height Dim height : Set height = New HeightValidation height.Init model.Height modelValidation.Add height Dim validatedProperties : Set validatedProperties = New CollectionClass Dim modelVal For Each modelVal In modelValidation.Items() validatedProperties.Add modelVal.Validate() Next Set ValidateModel = validatedProperties End Function End Class Dim modelCollection : Set modelCollection = New CollectionClass Dim user1 : Set user1 = New UserModel user1.Name = "Mike" user1.Age = 12 user1.Height = 32 modelCollection.Add user1 Dim user2 : Set user2 = New UserModel user2.Name = "Phil" user2.Age = 18 user2.Height = 432 modelCollection.Add user2 Dim user3 : Set user3 = New UserModel user3.Name = "Michele" user3.Age = 32 user3.Height = 324 modelCollection.Add user3 ' Validate all models in the collection Dim modelValue Dim validatedModels : Set validatedModels = New CollectionClass For Each modelValue In modelCollection.Items() Dim objModelValidator : Set objModelValidator = New ModelValidator validatedModels.Add objModelValidator.ValidateModel(modelValue) Next %> <table> <tr> <td>Name</td> <td>Age</td> <td>Height</td> </tr> <% Dim r, c For Each r In validatedModels.Items() %><tr><% For Each c In r.Items() %><td class="<%= c.CSSClass %>"><%= c.CellValue %></td><% Next %></tr><% Next %> </table> Thank you.

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  • Step by Step / Deep explain: The Power of (Co)Yoneda (preferably in scala) through Coroutines

    - by Mzk
    some background code /** FunctorStr: ? F[-]. (? A B. (A -> B) -> F[A] -> F[B]) */ trait FunctorStr[F[_]] { self => def map[A, B](f: A => B): F[A] => F[B] } trait Yoneda[F[_], A] { yo => def apply[B](f: A => B): F[B] def run: F[A] = yo(x => x) def map[B](f: A => B): Yoneda[F, B] = new Yoneda[F, B] { def apply[X](g: B => X) = yo(f andThen g) } } object Yoneda { implicit def yonedafunctor[F[_]]: FunctorStr[({ type l[x] = Yoneda[F, x] })#l] = new FunctorStr[({ type l[x] = Yoneda[F, x] })#l] { def map[A, B](f: A => B): Yoneda[F, A] => Yoneda[F, B] = _ map f } def apply[F[_]: FunctorStr, X](x: F[X]): Yoneda[F, X] = new Yoneda[F, X] { def apply[Y](f: X => Y) = Functor[F].map(f) apply x } } trait Coyoneda[F[_], A] { co => type I def fi: F[I] def k: I => A final def map[B](f: A => B): Coyoneda.Aux[F, B, I] = Coyoneda(fi)(f compose k) } object Coyoneda { type Aux[F[_], A, B] = Coyoneda[F, A] { type I = B } def apply[F[_], B, A](x: F[B])(f: B => A): Aux[F, A, B] = new Coyoneda[F, A] { type I = B val fi = x val k = f } implicit def coyonedaFunctor[F[_]]: FunctorStr[({ type l[x] = Coyoneda[F, x] })#l] = new CoyonedaFunctor[F] {} trait CoyonedaFunctor[F[_]] extends FunctorStr[({type l[x] = Coyoneda[F, x]})#l] { override def map[A, B](f: A => B): Coyoneda[F, A] => Coyoneda[F, B] = x => apply(x.fi)(f compose x.k) } def liftCoyoneda[T[_], A](x: T[A]): Coyoneda[T, A] = apply(x)(a => a) } Now I thought I understood yoneda and coyoneda a bit just from the types – i.e. that they quantify / abstract over map fixed in some type constructor F and some type a, to any type B returning F[B] or (Co)Yoneda[F, B]. Thus providing map fusion for free (? is this kind of like a cut rule for map ?). But I see that Coyoneda is a functor for any type constructor F regardless of F being a Functor, and that I don't fully grasp. Now I'm in a situation where I'm trying to define a Coroutine type, (I'm looking at https://www.fpcomplete.com/school/to-infinity-and-beyond/pick-of-the-week/coroutines-for-streaming/part-2-coroutines for the types to get started with) case class Coroutine[S[_], M[_], R](resume: M[CoroutineState[S, M, R]]) sealed trait CoroutineState[S[_], M[_], R] object CoroutineState { case class Run[S[_], M[_], R](x: S[Coroutine[S, M, R]]) extends CoroutineState[S, M, R] case class Done[R](x: R) extends CoroutineState[Nothing, Nothing, R] class CoroutineStateFunctor[S[_], M[_]](F: FunctorStr[S]) extends FunctorStr[({ type l[x] = CoroutineState[S, M, x]})#l] { override def map[A, B](f : A => B) : CoroutineState[S, M, A] => CoroutineState[S, M, B] = { ??? } } } and I think that if I understood Coyoneda better I could leverage it to make S & M type constructors functors way easy, plus I see Coyoneda potentially playing a role in defining recursion schemes as the functor requirement is pervasive. So how could I use coyoneda to make type constructors functors like for example coroutine state? or something like a Pause functor ?

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  • model binding of non-sequential arrays

    - by user281180
    I am having a table in which i`m dynamically creating and deleting rows. How can I change the code such that the rows be added and deleted and the model info property filled accordingly. Bearing in mind that the rows can be dynamically created and deleted, I may have Info[0], Inf0[3], info[4]... My objective is to be able to bind the array even if it`s not in sequence. Model public class Person { public int[] Size { get; set; } public string[] Name { get; set; } public Info[]info { get; set; } } public class Info { public string Address { get; set; } public string Tel { get; set; } View <script type="text/javascript" language="javascript"> $(function () { var count = 1; $('#AddSize').live('click', function () { $("#divSize").append('</br><input type="text" id="Size" name="Size" value=""/><input type = "button" id="AddSize" value="Add"/>'); }); $('#AddName').live('click', function () { $("#divName").append('</br><input type="text" id="Name" name="Name" value=""/><input type = "button" id="AddName" value="Add"/>'); }); $('#AddRow').live('click', function () { $('#details').append('<tr><td>Address</td><td> <input type="text" name="Info[' + count + '].Address"/></td><td>Tel</td><td><input type="text" name="Info[' + count++ + '].Tel"/></td> <td><input type="button" id="AddRow" value="Add"/> </td></tr>'); }); }); </script> </head> <body> <form id="closeForm" action="<%=Url.Action("Create",new{Action="Create"}) %>" method="post" enctype="multipart/form-data"> <div id="divSize"> <input type="text" name="Size" value=""/> <input type="button" value="Add" id="AddSize" /> </div> <div id="divName"> <input type="text" name="Name" value=""/> <input type="button" value="Add" id="AddName" /> </div> <div id="Tab"> <table id="details"> <tr><td>Address</td><td> <input type="text" name="Info[0].Address"/></td><td>Tel</td><td><input type="text" name="Info[0].Tel"/></td> <td><input type="button" id="AddRow" value="Add"/> </td></tr> </table> </div> <input type="submit" value="Submit" /> </form> </body> } Controller public ActionResult Create(Person person) { return new EmptyResult(); }

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  • Pure Server-Side Filtering with RadGridView and WCF RIA Services

    Those of you who are familiar with WCF RIA Services know that the DomainDataSource control provides a FilterDescriptors collection that enables you to filter data returned by the query on the server. We have been using this DomainDataSource feature in our RIA Services with DomainDataSource online example for almost an year now. In the example, we are listening for RadGridViews Filtering event in order to intercept any filtering that is performed on the client and translate it to something that the DomainDataSource will understand, in this case a System.Windows.Data.FilterDescriptor being added or removed from its FilterDescriptors collection. Think of RadGridView.FilterDescriptors as client-side filtering and of DomainDataSource.FilterDescriptors as server-side filtering. We no longer need the client-side one. With the introduction of the Custom Filtering Controls feature many new possibilities have opened. With these custom controls we no longer need to do any filtering on the client. I have prepared a very small project that demonstrates how to filter solely on the server by using a custom filtering control. As I have already mentioned filtering on the server is done through the FilterDescriptors collection of the DomainDataSource control. This collection holds instances of type System.Windows.Data.FilterDescriptor. The FilterDescriptor has three important properties: PropertyPath: Specifies the name of the property that we want to filter on (the left operand). Operator: Specifies the type of comparison to use when filtering. An instance of FilterOperator Enumeration. Value: The value to compare with (the right operand). An instance of the Parameter Class. By adding filters, you can specify that only entities which meet the condition in the filter are loaded from the domain context. In case you are not familiar with these concepts you might find Brad Abrams blog interesting. Now, our requirements are to create some kind of UI that will manipulate the DomainDataSource.FilterDescriptors collection. When it comes to collections, my first choice of course would be RadGridView. If you are not familiar with the Custom Filtering Controls concept I would strongly recommend getting acquainted with my step-by-step tutorial Custom Filtering with RadGridView for Silverlight and checking the online example out. I have created a simple custom filtering control that contains a RadGridView and several buttons. This control is aware of the DomainDataSource instance, since it is operating on its FilterDescriptors collection. In fact, the RadGridView that is inside it is bound to this collection. In order to display filters that are relevant for the current column only, I have applied a filter to the grid. This filter is a Telerik.Windows.Data.FilterDescriptor and is used to filter the little grid inside the custom control. It should not be confused with the DomainDataSource.FilterDescriptors collection that RadGridView is actually bound to. These are the RIA filters. Additionally, I have added several other features. For example, if you have specified a DataFormatString on your original column, the Value column inside the custom control will pick it up and format the filter values accordingly. Also, I have transferred the data type of the column that you are filtering to the Value column of the custom control. This will help the little RadGridView determine what kind of editor to show up when you begin edit, for example a date picker for DateTime columns. Finally, I have added four buttons two of them can be used to add or remove filters and the other two will communicate the changes you have made to the server. Here is the full source code of the DomainDataSourceFilteringControl. The XAML: <UserControl x:Class="PureServerSideFiltering.DomainDataSourceFilteringControl"    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"     xmlns:telerikGrid="clr-namespace:Telerik.Windows.Controls;assembly=Telerik.Windows.Controls.GridView"     xmlns:telerik="clr-namespace:Telerik.Windows.Controls;assembly=Telerik.Windows.Controls"     Width="300">     <Border x:Name="LayoutRoot"             BorderThickness="1"             BorderBrush="#FF8A929E"             Padding="5"             Background="#FFDFE2E5">           <Grid>             <Grid.RowDefinitions>                 <RowDefinition Height="Auto"/>                 <RowDefinition Height="150"/>                 <RowDefinition Height="Auto"/>             </Grid.RowDefinitions>               <StackPanel Grid.Row="0"                         Margin="2"                         Orientation="Horizontal"                         HorizontalAlignment="Center">                 <telerik:RadButton Name="addFilterButton"                                   Click="OnAddFilterButtonClick"                                   Content="Add Filter"                                   Margin="2"                                   Width="96"/>                 <telerik:RadButton Name="removeFilterButton"                                   Click="OnRemoveFilterButtonClick"                                   Content="Remove Filter"                                   Margin="2"                                   Width="96"/>             </StackPanel>               <telerikGrid:RadGridView Name="filtersGrid"                                     Grid.Row="1"                                     Margin="2"                                     ItemsSource="{Binding FilterDescriptors}"                                     AddingNewDataItem="OnFilterGridAddingNewDataItem"                                     ColumnWidth="*"                                     ShowGroupPanel="False"                                     AutoGenerateColumns="False"                                     CanUserResizeColumns="False"                                     CanUserReorderColumns="False"                                     CanUserFreezeColumns="False"                                     RowIndicatorVisibility="Collapsed"                                     IsFilteringAllowed="False"                                     CanUserSortColumns="False">                 <telerikGrid:RadGridView.Columns>                     <telerikGrid:GridViewComboBoxColumn DataMemberBinding="{Binding Operator}"                                                         UniqueName="Operator"/>                     <telerikGrid:GridViewDataColumn Header="Value"                                                     DataMemberBinding="{Binding Value.Value}"                                                     UniqueName="Value"/>                 </telerikGrid:RadGridView.Columns>             </telerikGrid:RadGridView>               <StackPanel Grid.Row="2"                         Margin="2"                         Orientation="Horizontal"                         HorizontalAlignment="Center">                 <telerik:RadButton Name="filterButton"                                   Click="OnApplyFiltersButtonClick"                                   Content="Apply Filters"                                   Margin="2"                                   Width="96"/>                 <telerik:RadButton Name="clearButton"                                   Click="OnClearFiltersButtonClick"                                   Content="Clear Filters"                                   Margin="2"                                   Width="96"/>             </StackPanel>           </Grid>       </Border> </UserControl>   And the code-behind: using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Windows; using System.Windows.Controls; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Animation; using System.Windows.Shapes; using Telerik.Windows.Controls.GridView; using System.Windows.Data; using Telerik.Windows.Controls; using Telerik.Windows.Data;   namespace PureServerSideFiltering {     /// <summary>     /// A custom filtering control capable of filtering purely server-side.     /// </summary>     public partial class DomainDataSourceFilteringControl : UserControl, IFilteringControl     {         // The main player here.         DomainDataSource domainDataSource;           // This is the name of the property that this column displays.         private string dataMemberName;           // This is the type of the property that this column displays.         private Type dataMemberType;           /// <summary>         /// Identifies the <see cref="IsActive"/> dependency property.         /// </summary>         /// <remarks>         /// The state of the filtering funnel (i.e. full or empty) is bound to this property.         /// </remarks>         public static readonly DependencyProperty IsActiveProperty =             DependencyProperty.Register(                 "IsActive",                 typeof(bool),                 typeof(DomainDataSourceFilteringControl),                 new PropertyMetadata(false));           /// <summary>         /// Gets or sets a value indicating whether the filtering is active.         /// </summary>         /// <remarks>         /// Set this to true if you want to lit-up the filtering funnel.         /// </remarks>         public bool IsActive         {             get { return (bool)GetValue(IsActiveProperty); }             set { SetValue(IsActiveProperty, value); }         }           /// <summary>         /// Gets or sets the domain data source.         /// We need this in order to work on its FilterDescriptors collection.         /// </summary>         /// <value>The domain data source.</value>         public DomainDataSource DomainDataSource         {             get { return this.domainDataSource; }             set { this.domainDataSource = value; }         }           public System.Windows.Data.FilterDescriptorCollection FilterDescriptors         {             get { return this.DomainDataSource.FilterDescriptors; }         }           public DomainDataSourceFilteringControl()         {             InitializeComponent();         }           public void Prepare(GridViewBoundColumnBase column)         {             this.LayoutRoot.DataContext = this;               if (this.DomainDataSource == null)             {                 // Sorry, but we need a DomainDataSource. Can't do anything without it.                 return;             }               // This is the name of the property that this column displays.             this.dataMemberName = column.GetDataMemberName();               // This is the type of the property that this column displays.             // We need this in order to see which FilterOperators to feed to the combo-box column.             this.dataMemberType = column.DataType;               // We will use our magic Type extension method to see which operators are applicable for             // this data type. You can go to the extension method body and see what it does.             ((GridViewComboBoxColumn)this.filtersGrid.Columns["Operator"]).ItemsSource                 = this.dataMemberType.ApplicableFilterOperators();               // This is very nice as well. We will tell the Value column its data type. In this way             // RadGridView will pick up the best editor according to the data type. For example,             // if the data type of the value is DateTime, you will be editing it with a DatePicker.             // Nice!             ((GridViewDataColumn)this.filtersGrid.Columns["Value"]).DataType = this.dataMemberType;               // Yet another nice feature. We will transfer the original DataFormatString (if any) to             // the Value column. In this way if you have specified a DataFormatString for the original             // column, you will see all filter values formatted accordingly.             ((GridViewDataColumn)this.filtersGrid.Columns["Value"]).DataFormatString = column.DataFormatString;               // This is important. Since our little filtersGrid will be bound to the entire collection             // of this.domainDataSource.FilterDescriptors, we need to set a Telerik filter on the             // grid so that it will display FilterDescriptor which are relevane to this column ONLY!             Telerik.Windows.Data.FilterDescriptor columnFilter = new Telerik.Windows.Data.FilterDescriptor("PropertyPath"                 , Telerik.Windows.Data.FilterOperator.IsEqualTo                 , this.dataMemberName);             this.filtersGrid.FilterDescriptors.Add(columnFilter);               // We want to listen for this in order to activate and de-activate the UI funnel.             this.filtersGrid.Items.CollectionChanged += this.OnFilterGridItemsCollectionChanged;         }           /// <summary>         // Since the DomainDataSource is a little bit picky about adding uninitialized FilterDescriptors         // to its collection, we will prepare each new instance with some default values and then         // the user can change them later. Go to the event handler to see how we do this.         /// </summary>         void OnFilterGridAddingNewDataItem(object sender, GridViewAddingNewEventArgs e)         {             // We need to initialize the new instance with some values and let the user go on from here.             System.Windows.Data.FilterDescriptor newFilter = new System.Windows.Data.FilterDescriptor();               // This is a must. It should know what member it is filtering on.             newFilter.PropertyPath = this.dataMemberName;               // Initialize it with one of the allowed operators.             // TypeExtensions.ApplicableFilterOperators method for more info.             newFilter.Operator = this.dataMemberType.ApplicableFilterOperators().First();               if (this.dataMemberType == typeof(DateTime))             {                 newFilter.Value.Value = DateTime.Now;             }             else if (this.dataMemberType == typeof(string))             {                 newFilter.Value.Value = "<enter text>";             }             else if (this.dataMemberType.IsValueType)             {                 // We need something non-null for all value types.                 newFilter.Value.Value = Activator.CreateInstance(this.dataMemberType);             }               // Let the user edit the new filter any way he/she likes.             e.NewObject = newFilter;         }           void OnFilterGridItemsCollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)         {             // We are active only if we have any filters define. In this case the filtering funnel will lit-up.             this.IsActive = this.filtersGrid.Items.Count > 0;         }           private void OnApplyFiltersButtonClick(object sender, RoutedEventArgs e)         {             if (this.DomainDataSource.IsLoadingData)             {                 return;             }               // Comment this if you want the popup to stay open after the button is clicked.             this.ClosePopup();               // Since this.domainDataSource.AutoLoad is false, this will take into             // account all filtering changes that the user has made since the last             // Load() and pull the new data to the client.             this.DomainDataSource.Load();         }           private void OnClearFiltersButtonClick(object sender, RoutedEventArgs e)         {             if (this.DomainDataSource.IsLoadingData)             {                 return;             }               // We want to remove ONLY those filters from the DomainDataSource             // that this control is responsible for.             this.DomainDataSource.FilterDescriptors                 .Where(fd => fd.PropertyPath == this.dataMemberName) // Only "our" filters.                 .ToList()                 .ForEach(fd => this.DomainDataSource.FilterDescriptors.Remove(fd)); // Bye-bye!               // Comment this if you want the popup to stay open after the button is clicked.             this.ClosePopup();               // After we did our housekeeping, get the new data to the client.             this.DomainDataSource.Load();         }           private void OnAddFilterButtonClick(object sender, RoutedEventArgs e)         {             if (this.DomainDataSource.IsLoadingData)             {                 return;             }               // Let the user enter his/or her requirements for a new filter.             this.filtersGrid.BeginInsert();             this.filtersGrid.UpdateLayout();         }           private void OnRemoveFilterButtonClick(object sender, RoutedEventArgs e)         {             if (this.DomainDataSource.IsLoadingData)             {                 return;             }               // Find the currently selected filter and destroy it.             System.Windows.Data.FilterDescriptor filterToRemove = this.filtersGrid.SelectedItem as System.Windows.Data.FilterDescriptor;             if (filterToRemove != null                 && this.DomainDataSource.FilterDescriptors.Contains(filterToRemove))             {                 this.DomainDataSource.FilterDescriptors.Remove(filterToRemove);             }         }           private void ClosePopup()         {             System.Windows.Controls.Primitives.Popup popup = this.ParentOfType<System.Windows.Controls.Primitives.Popup>();             if (popup != null)             {                 popup.IsOpen = false;             }         }     } }   Finally, we need to tell RadGridViews Columns to use this custom control instead of the default one. Here is how to do it: using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Windows; using System.Windows.Controls; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Animation; using System.Windows.Shapes; using System.Windows.Data; using Telerik.Windows.Data; using Telerik.Windows.Controls; using Telerik.Windows.Controls.GridView;   namespace PureServerSideFiltering {     public partial class MainPage : UserControl     {         public MainPage()         {             InitializeComponent();             this.grid.AutoGeneratingColumn += this.OnGridAutoGeneratingColumn;               // Uncomment this if you want the DomainDataSource to start pre-filtered.             // You will notice how our custom filtering controls will correctly read this information,             // populate their UI with the respective filters and lit-up the funnel to indicate that             // filtering is active. Go ahead and try it.             this.employeesDataSource.FilterDescriptors.Add(new System.Windows.Data.FilterDescriptor("Title", System.Windows.Data.FilterOperator.Contains, "Assistant"));             this.employeesDataSource.FilterDescriptors.Add(new System.Windows.Data.FilterDescriptor("HireDate", System.Windows.Data.FilterOperator.IsGreaterThan, new DateTime(1998, 12, 31)));             this.employeesDataSource.FilterDescriptors.Add(new System.Windows.Data.FilterDescriptor("HireDate", System.Windows.Data.FilterOperator.IsLessThanOrEqualTo, new DateTime(1999, 12, 31)));               this.employeesDataSource.Load();         }           /// <summary>         /// First of all, we will need to replace the default filtering control         /// of each column with out custom filtering control DomainDataSourceFilteringControl         /// </summary>         private void OnGridAutoGeneratingColumn(object sender, GridViewAutoGeneratingColumnEventArgs e)         {             GridViewBoundColumnBase dataColumn = e.Column as GridViewBoundColumnBase;             if (dataColumn != null)             {                 // We do not like ugly dates.                 if (dataColumn.DataType == typeof(DateTime))                 {                     dataColumn.DataFormatString = "{0:d}"; // Short date pattern.                       // Notice how this format will be later transferred to the Value column                     // of the grid that we have inside the DomainDataSourceFilteringControl.                 }                   // Replace the default filtering control with our.                 dataColumn.FilteringControl = new DomainDataSourceFilteringControl()                 {                     // Let the control know about the DDS, after all it will work directly on it.                     DomainDataSource = this.employeesDataSource                 };                   // Finally, lit-up the filtering funnel through the IsActive dependency property                 // in case there are some filters on the DDS that match our column member.                 string dataMemberName = dataColumn.GetDataMemberName();                 dataColumn.FilteringControl.IsActive =                     this.employeesDataSource.FilterDescriptors                     .Where(fd => fd.PropertyPath == dataMemberName)                     .Count() > 0;             }         }     } } The best part is that we are not only writing filters for the DomainDataSource we can read and load them. If the DomainDataSource has some pre-existing filters (like I have created in the code above), our control will read them and will populate its UI accordingly. Even the filtering funnel will light-up! Remember, the funnel is controlled by the IsActive property of our control. While this is just a basic implementation, the source code is absolutely yours and you can take it from here and extend it to match your specific business requirements. Below the main grid there is another debug grid. With its help you can monitor what filter descriptors are added and removed to the domain data source. Download Source Code. (You will have to have the AdventureWorks sample database installed on the default SQLExpress instance in order to run it.) Enjoy!Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • Sudo and startup script

    - by Pitto
    Hello my friends. I have a new asus 1215n and I need to digit commands to enable multitouch. No problem: I've made a script. Since this netbook also need manual activation of the wifi driver the complete script is: #!/bin/bash # # list of synaptics device properties http://www.x.org/archive/X11R7.5/doc/man/man4/synaptics.4.html#sect4 # list current synaptics device properties: xinput list-props '"SynPS/2 Synaptics TouchPad"' # sleep 5 #added delay... xinput set-int-prop "SynPS/2 Synaptics TouchPad" "Device Enabled" 8 1 xinput --set-prop --type=int --format=32 "SynPS/2 Synaptics TouchPad" "Synaptics Two-Finger Pressure" 4 xinput --set-prop --type=int --format=32 "SynPS/2 Synaptics TouchPad" "Synaptics Two-Finger Width" 9 # Below width 1 finger touch, above width simulate 2 finger touch. - value=pad-pixels xinput --set-prop --type=int --format=8 "SynPS/2 Synaptics TouchPad" "Synaptics Edge Scrolling" 1 1 0 # vertical, horizontal, corner - values: 0=disable 1=enable xinput --set-prop --type=int --format=32 "SynPS/2 Synaptics TouchPad" "Synaptics Jumpy Cursor Threshold" 250 # stabilize 2 finger actions - value=pad-pixels #xinput --set-prop --type=int --format=8 "SynPS/2 Synaptics TouchPad" "Synaptics Tap Action" 0 0 0 0 1 2 3 # pad corners rt rb lt lb tap fingers 1 2 3 (can't simulate more then 2 tap fingers AFAIK) - values: 0=disable 1=left 2=middle 3=right etc. (in FF 8=back 9=forward) xinput --set-prop --type=int --format=8 "SynPS/2 Synaptics TouchPad" "Synaptics Two-Finger Scrolling" 1 0 # vertical scrolling, horizontal scrolling - values: 0=disable 1=enable #xinput --set-prop --type=int --format=8 "SynPS/2 Synaptics TouchPad" "Synaptics Circular Scrolling" 1 #xinput --set-prop --type=int --format=8 "SynPS/2 Synaptics TouchPad" "Synaptics Circular Scrolling Trigger" 3 sudo modprobe lib80211 sudo insmod /home/pitto/Drivers/broadcom/wl.ko exit I've saved the script, then put it in my home, then chmod +x scriptname and then added it to startup applications. Then I did: sudo visudo and added this row: myusername ALL=(ALL) NOPASSWD: /home/scriptname rebooted and... Multitouch works but wifi not. When I manually launch the script it asks for sudo password so I thought it was because of modprobe and insmod commands and I've added those commands to sudo visudo. Nothing. What am I doing wrong?

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  • OSI Model

    - by kaleidoscope
    The Open System Interconnection Reference Model (OSI Reference Model or OSI Model) is an abstract description for layered communications and computer network protocol design. In its most basic form, it divides network architecture into seven layers which, from top to bottom, are the Application, Presentation, Session, Transport, Network, Data Link, and Physical Layers. It is therefore often referred to as the OSI Seven Layer Model. A layer is a collection of conceptually similar functions that provide services to the layer above it and receives service from the layer below it. Description of OSI layers: Layer 1: Physical Layer ·         Defines the electrical and physical specifications for devices. In particular, it defines the relationship between a device and a physical medium. ·         Establishment and termination of a connection to a communications medium. ·         Participation in the process whereby the communication resources are effectively shared among multiple users. ·         Modulation or conversion between the representation of digital data in user equipment and the corresponding signals transmitted over a communications channel. Layer 2: Data Link Layer ·         Provides the functional and procedural means to transfer data between network entities. ·         Detect and possibly correct errors that may occur in the Physical Layer. The error check is performed using Frame Check Sequence (FCS). ·         Addresses is then sought to see if it needs to process the rest of the frame itself or whether to pass it on to another host. ·         The Layer is divided into two sub layers: The Media Access Control (MAC) layer and the Logical Link Control (LLC) layer. ·         MAC sub layer controls how a computer on the network gains access to the data and permission to transmit it. ·         LLC layer controls frame synchronization, flow control and error checking.   Layer 3: Network Layer ·         Provides the functional and procedural means of transferring variable length data sequences from a source to a destination via one or more networks. ·         Performs network routing functions, and might also perform fragmentation and reassembly, and report delivery errors. ·         Network Layer Routers operate at this layer—sending data throughout the extended network and making the Internet possible.   Layer 4: Transport Layer ·         Provides transparent transfer of data between end users, providing reliable data transfer services to the upper layers. ·         Controls the reliability of a given link through flow control, segmentation/de-segmentation, and error control. ·         Transport Layer can keep track of the segments and retransmit those that fail. Layer 5: Session Layer ·         Controls the dialogues (connections) between computers. ·         Establishes, manages and terminates the connections between the local and remote application. ·         Provides for full-duplex, half-duplex, or simplex operation, and establishes checkpointing, adjournment, termination, and restart procedures. ·         Implemented explicitly in application environments that use remote procedure calls. Layer 6: Presentation Layer ·         Establishes a context between Application Layer entities, in which the higher-layer entities can use different syntax and semantics, as long as the presentation service understands both and the mapping between them. The presentation service data units are then encapsulated into Session Protocol data units, and moved down the stack. ·         Provides independence from differences in data representation (e.g., encryption) by translating from application to network format, and vice versa. The presentation layer works to transform data into the form that the application layer can accept. This layer formats and encrypts data to be sent across a network, providing freedom from compatibility problems. It is sometimes called the syntax layer. Layer 7: Application Layer ·         This layer interacts with software applications that implement a communicating component. ·         Identifies communication partners, determines resource availability, and synchronizes communication. o       When identifying communication partners, the application layer determines the identity and availability of communication partners for an application with data to transmit. o       When determining resource availability, the application layer must decide whether sufficient network or the requested communication exists. o       In synchronizing communication, all communication between applications requires cooperation that is managed by the application layer. Technorati Tags: Kunal,OSI,Networking

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  • SQL SERVER – An Efficiency Tool to Compare and Synchronize SQL Server Databases

    - by Pinal Dave
    There is no need to reinvent the wheel if it is already invented and if the wheel is already available at ease, there is no need to wait to grab it. Here is the similar situation. I came across a very interesting situation and I had to look for an efficient tool which can make my life easier and solve my business problem. Here is the scenario. One of the developers had deleted few rows from the very important mapping table of our development server (thankfully, it was not the production server). Though it was a development server, the entire development team had to stop working as the application started to crash on every page. Think about the lost of manpower and efficiency which we started to loose.  Pretty much every department had to stop working as our internal development application stopped working. Thankfully, we even take a backup of our development server and we had access to full backup of the entire database at 6 AM morning. We do not take as a frequent backup of development server as production server (naturally!). Even though we had a full backup, the solution was not to restore the database. Think about it, there were plenty of the other operations since the last good full backup and if we restore a full backup, we will pretty much overwrite on the top of the work done by developers since morning. Now, as restoring the full backup was not an option we decided to restore the same database on another server. Once we had restored our database to another server, the challenge was to compare the table from where the database was deleted. The mapping table from where the data were deleted contained over 5000 rows and it was humanly impossible to compare both the tables manually. Finally we decided to use efficiency tool dbForge Data Compare for SQL Server from DevArt. dbForge Data Compare for SQL Server is a powerful, fast and easy to use SQL compare tool, capable of using native SQL Server backups as metadata source. (FYI we Downloaded dbForge Data Compare) Once we discovered the product, we immediately downloaded the product and installed on our development server. After we installed the product, we were greeted with the following screen. We clicked on the New Data Comparision to start our new comparison project. It brought up following screen. Here is the best part of the product, we just had to enter our database connection username and password along with source and destination details and we are done. The entire process is very simple and self intuiting. The best part was that for the source, we can either select database or even backup. This was indeed fantastic feature. Think about this, if you have a very big database, it will take long time to restore on the server. Once it is restored, you will be able to work with it. However, when you are working with dbForge Data Compare it will accept database backup as your source or destination. Once I click on the execute it brought up following screen where it displayed an excellent summary of the data compare. It has dedicated tabs for the what is changing in what table as well had details of the changed data. The best part is that, once we had reviewed the change. We click on the Synchronize button in the menu bar and it brought up following screen. You can see that the screen has very simple straight forward but very powerful features. You can generate a script to synchronize from target to source or even from source to target. Additionally, the database is a very complicated world and there are extensive options to configure various database options on the next screen. We also have the option to either generate script or directly execute the script to target server. I like to play on the safe side and I generated the script for my synchronization and later on after review I deployed the scripts on the server. Well, my team and we were able to get going from our disaster in less than 10 minutes. There were few people in our team were indeed disappointed as they were thinking of going home early that day but in less than 10 minutes they had to get back to work. There are so many other features in  dbForge Data Compare for SQL Server, I am already planning to make this product company wide recommended product for Data Compare tool. Hats off to the team who have build this product. Here are few of the features salient features of the dbForge Data Compare for SQL Server Perform SQL Server database comparison to detect changes Compare SQL Server backups with live databases Analyze data differences between two databases Synchronize two databases that went out of sync Restore data of a particular table from the backup Generate data comparison reports in Excel and HTML formats Copy look-up data from development database to production Automate routine data synchronization tasks with command-line interface Go Ahead and Download the dbForge Data Compare for SQL Server right away. It is always a good idea to get familiar with the important tools before hand instead of learning it under pressure of disaster. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQL Utility, T SQL, Technology

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