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  • Up to date Ruby On Rails books?

    - by Earlz
    Hello, I've been trying to learn Rails for a while now and I just can not piece it all together with random blogs and SO questions, so I've decided I need a full book/ebook. Can anyone suggest a good one? I've been looking at Agile Web Development With Rails 4th edition. There is an old question about Ruby On Rails books but it is from 2008 and there has been new Rails releases since then. I basically would like a book that is more than a reference, but also doesn't assume I'm a non-programmer. Also, I already know a lot of Ruby. So, what books would you recommend that is up to date and also doesn't treat me like a baby?

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  • PostgreSQL storing paths for reference in scripts

    - by Brian D.
    I'm trying to find the appropriate place to store a system path in PostgreSQL. What I'm trying to do is load values into a table using the COPY command. However, since I will be referring to the same file path regularly I want to store that path in one place. I've tried creating a function to return the appropriate path, but I get a syntax error when I call the function in the COPY command. I'm not sure if this is the right way to go about it, but I'll post my code anyway. COPY command: COPY employee_scheduler.countries (code, name) FROM get_csv_path('countries.csv') WITH CSV; Function Definition: CREATE OR REPLACE FUNCTION employee_scheduler.get_csv_path(IN file_name VARCHAR(50)) RETURNS VARCHAR(250) AS $$ DECLARE path VARCHAR(200) := E'C:\\Brian\\Work\\employee_scheduler\\database\\csv\\'; file_path VARCHAR(250) := ''; BEGIN file_path := path || file_name; RETURN file_path; END; $$ LANGUAGE plpgsql; If anyone has a different idea on how to accomplish this I'm open to suggestions. Thanks for any help!

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  • Validating parameters according to a fixed reference

    - by James P.
    The following method is for setting the transfer type of an FTP connection. Basically, I'd like to validate the character input (see comments). Is this going overboard? Is there a more elegant approach? How do you approach parameter validation in general? Any comments are welcome. public void setTransferType(Character typeCharacter, Character optionalSecondCharacter) throws NumberFormatException, IOException { // http://www.nsftools.com/tips/RawFTP.htm#TYPE // Syntax: TYPE type-character [second-type-character] // // Sets the type of file to be transferred. type-character can be any // of: // // * A - ASCII text // * E - EBCDIC text // * I - image (binary data) // * L - local format // // For A and E, the second-type-character specifies how the text should // be interpreted. It can be: // // * N - Non-print (not destined for printing). This is the default if // second-type-character is omitted. // * T - Telnet format control (<CR>, <FF>, etc.) // * C - ASA Carriage Control // // For L, the second-type-character specifies the number of bits per // byte on the local system, and may not be omitted. final Set<Character> acceptedTypeCharacters = new HashSet<Character>(Arrays.asList( new Character[] {'A','E','I','L'} )); final Set<Character> acceptedOptionalSecondCharacters = new HashSet<Character>(Arrays.asList( new Character[] {'N','T','C'} )); if( acceptedTypeCharacters.contains(typeCharacter) ) { if( new Character('A').equals( typeCharacter ) || new Character('E').equals( typeCharacter ) ){ if( acceptedOptionalSecondCharacters.contains(optionalSecondCharacter) ) { executeCommand("TYPE " + typeCharacter + " " + optionalSecondCharacter ); } } else { executeCommand("TYPE " + typeCharacter ); } } }

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  • Approximate Number of CPU Cycles for Various Operations

    - by colordot
    I am trying to find a reference for approximately how many CPU cycles various operations require. I don't need exact numbers (as this is going to vary between CPUs) but I'd like something relatively credible that gives ballpark figures that I could cite in discussion with friends. As an example, we all know that floating point division takes more CPU cycles than say doing a bitshift. I'd guess that the difference is that the division is around 100 cycles, where as a shift is 1 but I'm looking for something to cite to back that up. Can anyone recommend such a resource?

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  • Qt: How to autoexpand parents of a new QTreeView item when using a QSortFilterProxyModel

    - by taynaron
    I'm making an app wherein the user can add new data to a QTreeModel at any time. The parent under which it gets placed is automatically expanded to show the new item: self.tree = DiceModel(headers) self.treeView.setModel(self.tree) expand_node = self.tree.addRoll() #addRoll makes a node, adds it, and returns the (parent) note to be expanded self.treeView.expand(expand_node) This works as desired. If I add a QSortFilterProxyModel to the mix: self.tree = DiceModel(headers) self.sort = DiceSort(self.tree) self.treeView.setModel(self.sort) expand_node = self.tree.addRoll() #addRoll makes a node, adds it, and returns the (parent) note to be expanded self.treeView.expand(expand_node) the parent no longer expands. Any idea what I am doing wrong?

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  • Translating 3-dimensional array reference onto 1-dimensional array

    - by user146780
    If there is an array of ar[5000] then how could I find where element [5][5][4] would be if this was a 3 dimensional array? Thanks I'm mapping pixels: imagine a bimap of [768 * 1024 * 4] where would pixel [5][5][4] be? I want to make this: static GLubyte checkImage[checkImageHeight][checkImageWidth][4]; static GLuint texName; bool itt; void makeCheckImage(void) { Bitmap *b = new Bitmap(L"c:/boo.png"); int i, j, c; Color cul; for (i = 0; i < checkImageHeight; i++) { for (j = 0; j < checkImageWidth; j++) { b->GetPixel(j,i,&cul); checkImage[i][j][0] = (GLubyte) cul.GetR(); checkImage[i][j][1] = (GLubyte) cul.GetG(); checkImage[i][j][2] = (GLubyte) cul.GetB(); checkImage[i][j][3] = (GLubyte) cul.GetA(); } } delete(b); } work without making a multidimensional array. width = 512, height = 1024....

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  • Looking for substantial open source GWT/App-Engine project to use as reference

    - by tempy
    I'm working on GAE-J/GWT app, wherein a desktop app connects to the GAE-J component, and there is also a web-app component whose front-end is written in GWT, and the GAE-J backend supports both the desktop app and the web app. I have a good amount of experience with writing pure server code and desktop code, but not so much on the web-app side of things. So I'm looking to study some good sophisticated open source code to see how other's have done things, but I can't find much open source GWT and/or GAE-J stuff, other than frameworks. Does anyone know of any good projects out there?

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  • Object pointer value as key into dictionary

    - by Ranking Stackingblocks
    I want to use the object's reference value as a key into a dictionary, as opposed to a copy of value of the object. So, I essentially want to store an object associated with a particular instance of another object in a dictionary and retrieve that value later. Is this possible? Is it completely against the idea of NSDictionary? I can tell that I am probably approaching this the wrong way because the dictionary wants me to implement NSCopying on the object itself, which doesn't really make sense in terms of what I'm doing. I can see that what I should really be doing is wrapping the pointer value, but that seems a little mad. Advice would be appreciated.

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  • DB Design - Linking to a parent without circular reference issues

    - by zSysop
    Hi all, I'm having trouble coming up with a solution for the following issue. Lets say i have a db that looks something like the following: Issue Table Id | Details | CreateDate | ClosedDate Issue Notes Table Id | ObjectId | Notes | NoteDate Issue Assignment Table Id | ObjectId | AssignedToId| AssignedDate I'd like allow the linking of an issue to another issue. I thought about adding a column to the Issue table called ParentIssueId and that would allow me the ability to link issues, but i foresee circular references occurring within the issue table if i go through with this implementation. Is there a better way to go about doing this, and if so, how? Thanks

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  • Doing a SetLength on an array passed into a proc by reference

    - by csharpdefector
    Hi All, Sure, even I can do this... var testarray : array of string; setlength(testarray, 5); but if I want to get clever and have a procedure into which I pass the array by referance like this I cant do it! procedure DoStuffWithArray(var passedarray : array of string); begin setlength(passedarray, 5); end; compiler says 'incompatible types' on the single line of code in my proc. I can do other stuff on the array like set set element values if i do a setlength before i call the proc, but I cannot do the setlength in my proc, which is what I want to do. Any help much appreciated, thanks all.

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  • Is it ok to reference .Net assemblies liberally?

    - by panamack
    I'm building a WPF application and working with the MVVM pattern. I have 4 projects in my solution, 3 class libraries, Data, Model and ViewModel and the WPF executable View. Is there anything wrong with the Model referencing WindowsBase so that I can use ObservableCollection<T> for example or can I just make use of what I intuitively feel I need without worrying about the original purposes of the class in the framework e.g. collection databinding.

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  • Using block around a static/singleton resource reference

    - by byte
    This is interesting (to me anyway), and I'd like to see if anyone has a good answer and explanation for this behavior. Say you have a singleton database object (or static database object), and you have it stored in a class Foo. public class Foo { public static SqlConnection DBConn = new SqlConnection(ConfigurationManager.ConnectionStrings["BAR"].ConnectionString); } Then, lets say that you are cognizant of the usefulness of calling and disposing your connection (pretend for this example that its a one-time use for purposes of illustration). So you decide to use a 'using' block to take care of the Dispose() call. using (SqlConnection conn = Foo.DBConn) { conn.Open(); using (SqlCommand cmd = new SqlCommand()) { cmd.Connection = conn; cmd.CommandType = System.Data.CommandType.StoredProcedure; cmd.CommandText = "SP_YOUR_PROC"; cmd.ExecuteNonQuery(); } conn.Close(); } This fails, with an error stating that the "ConnectionString property is not initialized". It's not an issue with pulling the connection string from the app.config/web.config. When you investigate in a debug session you see that Foo.DBConn is not null, but contains empty properties. Why is this?

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  • Is Android reference at android.com good enough

    - by the100rabh
    Hi, I am a C++ developer, but have a fair idea of Java as I learnt it in college 5years ago. I have been trying to learn programming for android. But instead of rushing to buy books, I have tried to read through the Android Dev Guide and learn from there making use of the sample applications. Thats besides SO ofcourse. I am trying to make some apps based on ideas I have. So my question is, Is it suitable or possible to learn android programming this way. Or is there something that I will be missing in all this.

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  • Backbone: Easiest way to maintain reference to 'this' for a Model inside callbacks

    - by Garrett
    var JavascriptHelper = Backbone.Model.extend("JavascriptHelper", {}, // never initialized as an instance { myFn: function() { $('.selector').live('click', function() { this.anotherFn(); // FAIL! }); }, anotherFn: function() { alert('This is never called from myFn()'); } } ); The usual _.bindAll(this, ...) approach won't work here because I am never initializing this model as an instance. Any ideas? Thanks.

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  • I need Selenium to open it's web browser in a larger resolution ( preferably maximized)

    - by user1854271
    I am using Selenium WebDriver and coding in Python I have looked all over the place and the best I could find were things written in different languages. I also tried to use the export tool on Selenium IDE but when I look at the data says that the function is not supported for export. EDIT: The reason I need the browser to open up with a larger resolution is because the web application that I am testing is supporting tablet resolution as so elements are different depending on the resolution of the browser window. This is the script I exported from the IDE with a couple of modifications. from selenium import webdriver from selenium.webdriver.common.by import By from selenium.webdriver.support.ui import Select from selenium.common.exceptions import NoSuchElementException import unittest, time, re from Funk_Lib import RS class CreatingEditingDeletingVault(unittest.TestCase): def setUp(self): self.driver = webdriver.Firefox() self.driver.implicitly_wait(30) self.base_url = "http://cimdev-qa40/" self.verificationErrors = [] def test_creating_editing_deleting_vault(self): driver = self.driver driver.get(self.base_url + "/Login?contoller=Home") driver.find_element_by_id("UserName").click() driver.find_element_by_id("UserName").clear() driver.find_element_by_id("UserName").send_keys("[email protected]") driver.find_element_by_name("Password").click() driver.find_element_by_name("Password").clear() driver.find_element_by_name("Password").send_keys("Codigo#123") driver.find_element_by_id("fat-btn").click() driver.get(self.base_url + "/Content/Vaults/") driver.find_element_by_link_text("Content").click() driver.find_element_by_link_text("Vaults").click() driver.find_element_by_css_selector("button.btn.dropdown-toggle").click() driver.find_element_by_link_text("New vault").click() driver.find_element_by_name("Name").clear() driver.find_element_by_name("Name").send_keys("Test Vault") driver.find_element_by_xpath("//button[@onclick=\"vault_action('createvault', null, $('#CreateVault [name=\\'Name\\']').val())\"]").click() driver.find_element_by_css_selector("button.btn.dropdown-toggle").click() driver.find_element_by_link_text("Rename vault").click() driver.find_element_by_name("Id").click() Select(driver.find_element_by_name("Id")).select_by_visible_text("Test Vault") driver.find_element_by_css_selector("option[value=\"2\"]").click() driver.find_element_by_name("Name").clear() driver.find_element_by_name("Name").send_keys("Test Change") driver.find_element_by_xpath("//button[@onclick=\"vault_action('renamevault', $('#RenameVault [name=\\'Id\\']').val(), $('#RenameVault [name=\\'Name\\']').val())\"]").click() driver.find_element_by_css_selector("button.btn.dropdown-toggle").click() driver.find_element_by_link_text("Delete vault").click() driver.find_element_by_name("Id").click() Select(driver.find_element_by_name("Id")).select_by_visible_text("Test Change") driver.find_element_by_css_selector("option[value=\"2\"]").click() driver.find_element_by_xpath("//button[@onclick=\"vault_action('deletevault', $('#DeleteVault [name=\\'Id\\']').val(), '')\"]").click() def is_element_present(self, how, what): try: self.driver.find_element(by=how, value=what) except NoSuchElementException, e: return False return True def tearDown(self): self.driver.quit() self.assertEqual([], self.verificationErrors) if __name__ == "__main__": unittest.main()

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  • threading.Event wait function not signaled when subclassing Process class

    - by user1313404
    For following code never gets past the wait function in run. I'm certain I'm doing something ridiculously stupid, but since I'm not smart enough to figure out what, I'm asking. Any help is appreciated. Here is the code: import threading import multiprocessing from multiprocessing import Process class SomeClass(Process): def __init__(self): Process.__init__(self) self.event = threading.Event() self.event.clear() def continueExec(self): print multiprocessing.current_process().name print self print "Set:" + str(self.event.is_set()) self.event.set() print "Set:" + str(self.event.is_set()) def run(self): print "I'm running with it" print multiprocessing.current_process().name self.event.wait() print "I'm further than I was" print multiprocessing.current_process().name self.event.clear() def main(): s_list = [] for t in range(3): s = SomeClass() print "s:" + str(s) s_list.append(s) s.start() raw_input("Press enter to send signal") for t in range(3): print "s_list["+str(t)+"]:" + str(s_list[t]) s_list[t].continueExec() raw_input("Press enter to send signal") for t in range(3): s_list[t].join() print "All Done" if __name__ == "__main__": main()

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  • Is there a definitive list of uri patterns for use in android apps made by google?

    - by The Trav
    Apart from http://developer.android.com/guide/appendix/g-app-intents.html (which is quite good but fairly limited in the number of apps/uri's it covers) I've been unable to find a decent reference source for looking up URI's to use when integrating with google apps. I'm currently working on triggering the "add new contact" UI, and have found that the tel: uri pattern seems to work, but what if I only have a name and an email? I wouldn't have expected I'd need to rely on sample code / trial and error, but I really can't see anywhere where the intent/URI interface is supposed to be documented in android apps. Does such a standard exist? Is there some quasi standard / user database that I can consult? On a platform with such a good inter-interoperability architecture it just seems like something so useful I can't believe it's not there

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  • C# - What is root reference ?

    - by DotNetGuy
    class GCTest { static Object r1; static void Main() { r1 = new Object(); Object r2 = new Object(); Object r3 = new Object(); System.GC.Collect(); // what can be reclaimed here ? r1 = null; r3.ToString(); System.GC.Collect(); // what can be reclaimed here ? } } // code from - DonBox's Essential .Net

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  • Flask Admin didn't show all fields

    - by twoface88
    I have model like this: class User(db.Model): __tablename__ = 'users' __table_args__ = {'mysql_engine' : 'InnoDB', 'mysql_charset' : 'utf8'} id = db.Column(db.Integer, primary_key=True) username = db.Column(db.String(80), unique=True) email = db.Column(db.String(120), unique=True) _password = db.Column('password', db.String(80)) def __init__(self, username = None, email = None, password = None): self.username = username self.email = email self._set_password(password) def _set_password(self, password): self._password = generate_password_hash(password) def _get_password(self): return self._password def check_password(self, password): return check_password_hash(self._password, password) password = db.synonym("_password", descriptor=property(_get_password, _set_password)) def __repr__(self): return '<User %r>' % self.username I have ModelView: class UserAdmin(sqlamodel.ModelView): searchable_columns = ('username', 'email') excluded_list_columns = ['password'] list_columns = ('username', 'email') form_columns = ('username', 'email', 'password') But no matter what i do, flask admin didn't show password field when i'm editing user info. Is there any way ? Even just to edit hash code. UPDATE: https://github.com/mrjoes/flask-admin/issues/78

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  • Qt gstreamer problem

    - by ZolaKt
    Ptterb can you post your full code please? I copied your code. Added fvidscale_cap to pipeline, with: self.player.add(self.source, self.scaler, self.fvidscale_cap, self.sink) gst.element_link_many(self.source,self.scaler, self.fvidscale_cap, self.sink) From the main program I create a new QWidget, and pass its winId() to Vid constructor. The widget start loading, but crashes. The output says: should be playing Segmentation fault

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  • Redeclaration of parameters

    - by Scott
    While looking through the Selenium source code I noticed the following in the PageFactory: public static <T> T initElements(WebDriver driver, Class<T> pageClassToProxy) { T page = instantiatePage(driver, pageClassToProxy); initElements(driver, page); return page; } public static void initElements(WebDriver driver, Object page) { final WebDriver driverRef = driver; initElements(new DefaultElementLocatorFactory(driverRef), page); } What is the benefit of having the following line? final WebDriver driverRef = driver; Wouldn't it have made sense to just make the parameter final, and then passing that along to the next method without declaring the new reference?

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  • Iterating over member typed collection fails when using untyped reference to generic object

    - by Alexander Pavlov
    Could someone clarify why iterate1() is not accepted by compiler (Java 1.6)? I do not see why iterate2() and iterate3() are much better. This paragraph is added to avoid silly "Your post does not have much context to explain the code sections; please explain your scenario more clearly." protection. import java.util.Collection; import java.util.HashSet; public class Test<T> { public Collection<String> getCollection() { return new HashSet<String>(); } public void iterate1(Test test) { for (String s : test.getCollection()) { // ... } } public void iterate2(Test test) { Collection<String> c = test.getCollection(); for (String s : c) { // ... } } public void iterate3(Test<?> test) { for (String s : test.getCollection()) { // ... } } } Compiler output: $ javac Test.java Test.java:11: incompatible types found : java.lang.Object required: java.lang.String for (String s : test.getCollection()) { ^ Note: Test.java uses unchecked or unsafe operations. Note: Recompile with -Xlint:unchecked for details. 1 error

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