Search Results

Search found 7284 results on 292 pages for 'rails 3'.

Page 288/292 | < Previous Page | 284 285 286 287 288 289 290 291 292  | Next Page >

  • Can a standalone ruby script (windows and mac) reload and restart itself?

    - by user30997
    I have a master-workers architecture where the number of workers is growing on a weekly basis. I can no longer be expected to ssh or remote console into each machine to kill the worker, do a source control sync, and restart. I would like to be able to have the master place a message out on the network that tells each machine to sync and restart. That's where I hit a roadblock. If I were using any sane platform, I could just do: exec('ruby', __FILE__) ...and be done. However, I did the following test: p Process.pid sleep 1 exec('ruby', __FILE__) ...and on Windows, I get one ruby instance for each call to exec. None of them die until I hit ^C on the window in question. On every platform I tried this on, it is executing the new version of the file each time, which I have verified this by making simple edits to the test script while the test marched along. The reason I'm printing the pid is to double-check the behavior I'm seeing. On windows, I am getting a different pid with each execution - which I would expect, considering that I am seeing a new process in the task manager for each run. The mac is behaving correctly: the pid is the same for every system call and I have verified with dtrace that each run is trigging a call to the execve syscall. So, in short, is there a way to get a windows ruby script to restart its execution so it will be running any code - including itself - that has changed during its execution? Please note that this is not a rails application, though it does use activerecord.

    Read the article

  • sqlalchemy relation through another (declarative)

    - by clayg
    Is anyone familiar with ActiveRecord's "has_many :through" relations for models? I'm not really a Rails guy, but that's basically what I'm trying to do. As a contrived example consider Projects, Programmers, and Assignments: from sqlalchemy import create_engine from sqlalchemy.orm import sessionmaker from sqlalchemy import Column, ForeignKey from sqlalchemy.types import Integer, String, Text from sqlalchemy.orm import relation from sqlalchemy.ext.declarative import declarative_base Base = declarative_base() class Assignment(Base): __tablename__ = 'assignment' id = Column(Integer, primary_key=True) description = Column(Text) programmer_id = Column(Integer, ForeignKey('programmer.id')) project_id = Column(Integer, ForeignKey('project.id')) def __init__(self, description=description): self.description = description def __repr__(self): return '<Assignment("%s")>' % self.description class Programmer(Base): __tablename__ = 'programmer' id = Column(Integer, primary_key=True) name = Column(String(64)) assignments = relation("Assignment", backref='programmer') def __init__(self, name=name): self.name = name def __repr__(self): return '<Programmer("%s")>' % self.name class Project(Base): __tablename__ = 'project' id = Column(Integer, primary_key=True) name = Column(String(64)) description = Column(Text) assignments = relation("Assignment", backref='project') def __init__(self, name=name, description=description): self.name = name self.description = description def __repr__(self): return '<Project("%s", "%s...")>' % (self.name, self.description[:10]) engine = create_engine('sqlite://') Base.metadata.create_all(engine) Session = sessionmaker(bind=engine) session = Session() Projects have many Assignments. Programmers have many Assignments. (understatement?) But in my office at least, Programmers also have many Projects - I'd like this relationship to be inferred through the Assignments assigned to the Programmer. I'd like the Programmer model to have a attribute "projects" which will return a list of Projects associated to the Programmer through the Assignment model. me = session.query(Programmer).filter_by(name='clay').one() projects = session.query(Project).\ join(Project.assignments).\ join(Assignment.programmer).\ filter(Programmer.id==me.id).all() How can I describe this relationship clearly and simply using the sqlalchemy declarative syntax? Thanks!

    Read the article

  • phppgadmin : How does it kick users out of postgres, so it can db_drop?

    - by egarcia
    I've got one Posgresql database (I'm the owner) and I'd like to drop it and re-create it from a dump. Problem is, there're a couple applications (two websites, rails and perl) that access the db regularly. So I get a "database is being accessed by other users" error. I've read that one possibility is getting the pids of the processes involved and killing them individually. I'd like to do something cleaner, if possible. Phppgadmin seems to do what I want: I am able to drop schemas using its web interface, even when the websites are on, without getting errors. So I'm investigating how its code works. However, I'm no PHP expert. I'm trying to understand the phppgadmin code in order to see how it does it. I found out a line (257 in Schemas.php) where it says: $data->dropSchema(...) $data is a global variable and I could not find where it is defined. Any pointers would be greatly appreciated.

    Read the article

  • XMPP4R Callbacks dont seem to work

    - by Sid
    Im using xmpp4r and trying to get the hang of a basic chat feature that I wish to implement later in my Rails app. My fundamentals on Ruby Threads is still a bit shaky so I would appreciate any help on this. Though I register the callback i dont get a response from my gmail account. I am able to send a message but my ruby program terminates. In order to prevent it from terminating I tried to stop on of the threads in the program but I cant seem to get it working. require 'rubygems' require "xmpp4r/client" require "xmpp4r/roster" include Jabber def connect client = Client.new(JID::new("[email protected]")) client.connect client.auth("test") client.send(Presence.new.set_type(:available)) client end def create_message(message, to_email) msg = Jabber::Message::new(to_email, message) msg.type = :chat msg end def subscribe(email_id) pres = Presence.new.set_type(:subscribe).set_to(email_id) pres end client = connect roster = Roster::Helper.new(client) roster.add_subscription_request_callback do |item,pres| roster.accept_subscription(pres.from) end def create_callback(client) $t4= Thread.new do client.add_message_callback do |m| puts m.body puts "................................Callback working" end end end puts "Client has connected" msg = create_message("Welcome to the winter of my discontent", "[email protected]") client.send(msg) create_callback(client) def check(client) $t3 = Thread.new do loop do puts "t3 still running........." Thread.current.stop $t4.join end end end check(client)

    Read the article

  • What is a good programming language/environment for Linux database applications?

    - by Dkellygb
    I could use some advice on my move from the Windows world to Linux. For my business, I have used VB6 and Microsoft Access with both Access databases and SQL server in the past. The easy to use forms, report writers and programming language were perfect for CRUD apps and analysis for our small hotel/restaurant business. After using Linux at home for some time I would like to convert our small business. Our server is already a Linux box using Samba. I am happy with the OpenOffice.org applications instead of Microsoft Office. The only thing which is holding me back is a desktop database application where I can develop the forms and reports we require. Base does not seem to be up to the job yet from my experience. I would like something like VB.Net with visual studio (express) but I would like to avoid Mono – I just don’t see the point of it. (You can correct me if I’m wrong.) But a good collection of forms, controls and a good report writer would be ideal. I have looked at web based stuff like Ruby on Rails, but I think a webserver for our 5 pc network is overkill. I don’t mind running a proper database on our Ubuntu 9.10 server. I may have exposed a few prejudices above but my mind is open. Any thoughts?

    Read the article

  • How much does Website Development cost nowadays?

    - by Andreas Grech
    I am thinking of setting up my own freelance business but coming from a workplace that offers a particular service to huge clients, I do not know what are the current charges for websites are nowadays. I know that as technology just keeps changing and changing (most of the time, for the better...), the amount you charge for a single website is constantly differing. Like for example, I don't think static websites (with just static html pages) are that expensive today, no? (as i said, I might be mistaken since I haven't really touched on this freelance industry yet) So, freelance web-developers out there, can you give me estimates on how much you charge for your clients? Some examples of websites that I want to know an approx charge: ~10 static html pages ~10 dhtml pages (with maybe a flasy menu on the top/side) Database driven websites with a standard CMS (be it the one you developed, or an existing one) Database driven but with a custom-built cms for the particular client Using an existing template for a design Starting the design from scratch etc... I know that the normally clients don't really care about the technologies used to construct their websites, but do you charge differently according to which technology you use to build the website with?; as in, is the technology a factor when setting the price? ...being ASP.Net, PHP, Ruby On Rails etc... Also, how do you go on about charging your clients for your services? What are the major factors that you consider when setting a price tag for a website to a client ? And better yet, how do you even find prospective clients? <= [or should I leave this question for a different post?] Btw, in your post, also mention some numbers (in cash values, be it in USD, GBP, EUR or anything) because I want to be able to take calculate some averages from this post when some answers stack up

    Read the article

  • User preferences using SQL and JavaScript

    - by Shyam
    Hi, I am using Server Side JavaScript - yes, I am actually using Server Side JavaScript. To complexify things even more, I use Oracle as a backend database (10g). With some crazy XSLT and mutant-like HTML generation, I can build really fancy web forms - yes, I am aware of Rails and other likewise frameworks and I choose the path of horror instead. I have no JQuery or other fancy framework at my disposal, just plain ol' JavaScript that should be supported by the underlying engine called Mozilla Rhino. Yes, it is insane and I love it. So, I have a bunch of tables at my disposal and some of them are filled with associative keys that link to values. As I am a people pleaser, I want to add some nifty user-preference driven solutions. My users have all an unique user_id and this user_id is available during the entire session. My initial idea is to have a user preference table, where I have "three" columns: user_id, feature and pref_string. Using a delimiter, such as : or - (haven't thought about a suitable one yet), I could like store a bunch of preferences as a list and store its elements inside an array using the .split-method (similar like the PHP-explode function). The feature column could be like the table name or some identifier for the "feature" i want to link preferences too. I hate hardcoding objects, especially as I want to be able to back these up and reuse this functionality application-wide. Of course I would love better ideas, just keep in mind I cannot just add a library that easily. These preferences could be like "joined" to the table, so I can query it and use its values. I hope it doesn't sounds too complex, because well.. its basically something really simple I need. Thanks!

    Read the article

  • How did this happen?? Git error? Some other fluke?

    - by marfarma
    Every file in this Rails project is duplicated with a -e and again with a -e-e tacked onto the end of it, like the following. It's that way in my GitHub repository too. But I can't figure out how it happened. Any clue? Google searching comes up empty. -rw-r--r--@ 1 usrname staff 959 Jan 7 02:13 Gemfile -rw-r--r-- 1 usrname staff 958 Jan 5 01:10 Gemfile-e -rw-r--r-- 1 usrname staff 958 Jan 5 01:09 Gemfile-e-e -rw-r--r-- 1 usrname staff 6650 Jan 7 02:13 Gemfile.lock -rw-r--r-- 1 usrname staff 6650 Jan 5 01:10 Gemfile.lock-e -rw-r--r-- 1 usrname staff 6650 Jan 5 01:09 Gemfile.lock-e-e lrwxr-xr-x 1 usrname staff 18 Jan 5 00:37 README.rdoc - doc/README_FOR_APP -rw-r--r-- 1 usrname staff 283 Jan 5 01:10 Rakefile -rw-r--r-- 1 usrname staff 283 Jan 5 01:10 Rakefile-e -rw-r--r-- 1 usrname staff 283 Jan 5 01:09 Rakefile-e-e drwxr-xr-x 6 usrname staff 204 Jan 5 00:37 app drwxr-xr-x 5 usrname staff 170 Jan 5 01:10 autotest drwxr-xr-x 28 usrname staff 952 Jan 5 01:15 config -rw-r--r-- 1 usrname staff 173 Jan 5 01:10 config.ru -rw-r--r-- 1 usrname staff 173 Jan 5 01:10 config.ru-e -rw-r--r-- 1 usrname staff 173 Jan 5 01:09 config.ru-e-e

    Read the article

  • Help me choose a web development framework/platform that will make me learn something

    - by Sergio Tapia
    I'm having a bit of an overload of information these past two days. I'm planning to start my own website that will allow local businesses to list their items on sale, and then users can come in and search for "Abercrombie t-shirt" and the stores that sell them will be listed. It's a neat little project I'm really excited for and I'm sure it'll take off, but I'm having problems from the get go. Sure I could use ASP.Net for it, I'm a bit familiar with it and the IDE for ASP.Net pages is bar-none, but I feel this is a great chance for me to learn something new to branch out a bit and not regurgitate .NET like a robot. I've been looking and asking around but it's all just noise and I can't make an educated decision. Can you help me choose a framework/platform that will make me learn something that's a nice thing to know in the job market, but also nice for me to grow as a professional? So far I've looked at: Ruby on Rails Kohana CakePHP CodeIgniter Symfony But they are all very esoteric to me, and I have trouble even finding out which IDE to use to that will let me use auto-complete for the proprietary keywords/methods. Thank you for your time.

    Read the article

  • How to jQuery plugin effects to items created later in the DOM

    - by Dan Denney
    How do I apply jQuery plugin effects to items that are created by an event? So, what I am attempting to do is have all uls throughout a site use the jquery.scroll.js plugin for styling. I currently have it working on all active uls. However, there are some category/subcategory sections. I am still new to writing any jQuery on my own and there is a leap in logic that I don't understand on applying plugins to items when they are loaded later. In the real example, users click a category from a ul and a sub category is loaded via Rails and JSON. For a light sample, I made a jsfiddle that simulates the issue that I run into. The category ul is styled correctly, but the subcategory ul doesn't pick up the styling. I'm hoping for some assistance not just in whipping up some code to fix it, but in pointing me in the direction of what I need to learn for this functionality. http://jsfiddle.net/dandenney/25R8F/1/ Thank you in advance!

    Read the article

  • Managing inverse relationships without CoreData

    - by Nathaniel Martin
    This is a question for Objective-J/Cappuccino, but I added the cocoa tag since the frameworks are so similar. One of the downsides of Cappuccino is that CoreData hasn't been ported over yet, so you have to make all your model objects manually. In CoreData, your inverse relationships get managed automatically for you... if you add an object to a to-many relationship in another object, you can traverse the graph in both directions. Without CoreData, is there any clean way to setup those inverse relationships automatically? For a more concrete example, let's take the typical Department and Employees example. To use rails terminology, a Department object has-many Employees, and an Employee belongs-to a Department. So our Department model has an NSMutableSet (or CPMutableSet ) "employees" that contains a set of Employees, and our Employee model has a variable "department" that points back to the Department model that owns it. Is there an easy way to make it so that, when I add a new Employee model into the set, the inverse relationship (employee.department) automatically gets set? Or the reverse: If I set the department model of an employee, then it automatically gets added to that department's employee set? Right know I'm making an object, "ValidatedModel" that all my models subclass, which adds a few methods that setup the inverse relationships, using KVO. But I'm afraid that I'm doing a lot of pointless work, and that there's already an easier way to do this. Can someone put my concerns to rest?

    Read the article

  • How to set the VirtualDocumentRoot based on the files within

    - by Chuck Vose
    I'm trying to set up Apache to use the VirtualDocumentRoot directive but my sites aren't all exactly the same. Most of the sites have a drupal folder which should be the root but there are a few really old drupal sites, a few rails sites, some django sites, etc. that want the Document root to be / or some other folder. Is there a way to set up VirtualDocumentRoot based on a conditional or is there a way to use RewriteRule/Cond to detect that / is the incorrect folder if there is a drupal folder or a public folder? Here's what I have so far: <VirtualHost *:80> # Wildcard ServerAlias, this is the default vhost if no specific vhost matches first. ServerAlias *.unicorn.devserver.com # Automatic ServerName, based on the HTTP_HOST header. UseCanonicalName Off # Automatic DocumentRoot. This uses the 4th level domain name as the document root, # for example http://bar.foo.baz.com/ would respond with /Users/vosechu/Sites/bar/drupal. VirtualDocumentRoot /Users/vosechu/Sites/%-4/drupal </VirtualHost> Thanks in advance! -Chuck

    Read the article

  • Is there a supplementary guide/answer key for ruby koans?

    - by corroded
    I have recently tried sharpening my rails skills with this tool: http://github.com/edgecase/ruby_koans but I am having trouble passing some tests. Also I am not sure if I'm doing some things correctly since the objective is just to pass the test, there are a lot of ways in passing it and I may be doing something that isn't up to standards. Is there a way to confirm if I'm doing things right? a specific example: in about_nil, def test_nil_is_an_object assert_equal __, nil.is_a?(Object), "Unlike NULL in other languages" end so is it telling me to check if that second clause is equal to an object(so i can say nil is an object) or just put assert_equal true, nil.is_a?(Object) because the statement is true? and the next test: def test_you_dont_get_null_pointer_errors_when_calling_methods_on_nil # What happens when you call a method that doesn't exist. The # following begin/rescue/end code block captures the exception and # make some assertions about it. begin nil.some_method_nil_doesnt_know_about rescue Exception => ex # What exception has been caught? assert_equal __, ex.class # What message was attached to the exception? # (HINT: replace __ with part of the error message.) assert_match(/__/, ex.message) end end Im guessing I should put a "No method error" string in the assert_match, but what about the assert_equal?

    Read the article

  • Installing Ruby via rbenv fails

    - by Maximus S
    Problem: I installed ruby, but it is not recognized correctly. I'm following the deploying to VPS: https://github.com/railscasts/335-deploying-to-a-vps I am setting my server on ubuntu 12.04 LTS to deploy my rails app. I'm following the railscast on deploying to a VPS, and trying to install ruby through rbenv. It seemed everything was installed correctly, but when I tried to check the ruby version, it gave me errors. The following are the commands that I ran. deployer@max:~$ rbenv install 1.9.3-p125 Downloading yaml-0.1.4.tar.gz... -> http://cloud.github.com/downloads/sstephenson/ruby-build-download-mirror/36c852831d02cf90508c29852361d01b Installing yaml-0.1.4... Installed yaml-0.1.4 to /home/deployer/.rbenv/versions/1.9.3-p125 Downloading ruby-1.9.3-p125.tar.gz... -> http://cloud.github.com/downloads/sstephenson/ruby-build-download-mirror/e3ea86b9d3fc2d3ec867f66969ae3b92 Installing ruby-1.9.3-p125... Installed ruby-1.9.3-p125 to /home/deployer/.rbenv/versions/1.9.3-p125 Downloading rubygems-1.8.23.tar.gz... -> http://cloud.github.com/downloads/sstephenson/ruby-build-download-mirror/178b0ebae78dbb46963c51ad29bb6bd9 Installing rubygems-1.8.23... Installed rubygems-1.8.23 to /home/deployer/.rbenv/versions/1.9.3-p125 deployer@max:~$ rbenv global 1.9.3-p125 deployer@max:~$ ruby -v 'ruby' program can be found in the following packages: * ruby1.8 * ruby1.9.1 How do I solve this?

    Read the article

  • Selenium: Can i test if a page loaded a flash app (ie a swf) properly?

    - by Max Williams
    hi all. I'm writing some selenium tests (in rspec for a rails app). One of my pages loads a swf and while i don't want to test the functionality of this flash app i do want to test that it loaded up ok. Is this possible? In case it helps, the html to load the swf is: <OBJECT classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000" codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=8,0,0,0" width="800" height="600"> <PARAM NAME=movie VALUE="http://localhost:3000/assets/players/millionaire/millionaire.swf"> <PARAM NAME=quality VALUE="high"> <PARAM NAME=FlashVars VALUE="quizXML=http://localhost:3000/quizzes/371.xml?online=true&myURL=http://localhost:3000/assets/players/millionaire/&online=true"> <param name=width value="800"> <param name=height value="600"> <EMBED src="http://localhost:3000/assets/players/millionaire/millionaire.swf" FlashVars="quizXML=http://localhost:3000/quizzes/371.xml?online=true&myURL=http://localhost:3000/assets/players/millionaire/&online=true" width="800" height="600" quality=high TYPE="application/x-shockwave-flash" PLUGINSPAGE="http://www.macromedia.com/go/getflashplayer"> </EMBED> </OBJECT> thanks - max

    Read the article

  • How to fetch and populate backbone model for Google Places JS API?

    - by code-gijoe
    I'm implementing a system that require access to Google Places JS API. I've been using rails for most of the project, but now I want to inject a bit of AJAX in one of my views. Basically it is a view that displays places near your location. For this, I'm using the JS API of Google places. A quick workflow would be: 1- The user inputs a text query and hits enter. 2- There is an AJAX call to request data from Google Places API. 3- The successful result is presented to the user. The problem is primarily in step 2. I want to use backbone for this but when I create a backbone model, it requests to the 'rootURL'. This wouldn't be a problem if the requests to Places was done from the server but it is not. A place call is done like this: service = new google.maps.places.PlacesService(map); service.nearbySearch(request, callback); Passing a callback function: function callback(results, status) { if (status == google.maps.places.PlacesServiceStatus.OK) { for (var i = 0; i < results.length; i++) { var place = results[i]; createMarker(results[i]); } } } Is it possible to override the 'fetch' method in backbone model and populate the model with the successful Places result? Is this a bad idea?

    Read the article

  • Problem Render backbone collection using Mustache template

    - by RameshVel
    I am quite new to backbone js and Mustache. I am trying to load the backbone collection (Object array) on page load from rails json object to save the extra call . I am having troubles rendering the backbone collection using mustache template. My model & collection are var Item = Backbone.Model.extend({ }); App.Collections.Items= Backbone.Collection.extend({ model: Item, url: '/items' }); and view App.Views.Index = Backbone.View.extend({ el : '#itemList', initialize: function() { this.render(); }, render: function() { $(this.el).html(Mustache.to_html(JST.item_template(),this.collection )); //var test = {name:"test",price:100}; //$(this.el).html(Mustache.to_html(JST.item_template(),test )); } }); In the above view render, i can able to render the single model (commented test obeject), but not the collections. I am totally struck here, i have tried with both underscore templating & mustache but no luck. And this is the Template <li> <div> <div style="float: left; width: 70px"> <a href="#"> <img class="thumbnail" src="http://placehold.it/60x60" alt=""> </a> </div> <div style="float: right; width: 292px"> <h4> {{name}} <span class="price">Rs {{price}}</span></h4> </div> </div> </li> and my object array kind of looks like this

    Read the article

  • How to disable firefox's form auto completion without change events?

    - by Dmitriy Likhten
    So firefox has a nifty mechanism which will try to autocomplete values in fields when a page is reloaded or the back button is used. Which is great and all except when you have something like a drop-down which when set to a value modifies the page using ajax. What winds up happening is that the browser reloads the page, the drop down is pre-filled with the remembered value, and then no change event is fired when the dom is ready. And therefore the change handlers attached don't fire and thus the page does not update. Is there a good way to "fix" this behavior so that it works for the user as expected: a) We do want the browser to auto-complete because that is a good user experience. b) Still want that onchange event firing. The only thing I can think of doing at the moment is to add an on-ready event to the document which has javascript pre-populated with initial values in the form, when the document loads the javascript will check the pre-populated values and if not matching what is in the input will trigger the change handlers. Anyone have a better solution? Is there a lib that does this already? (Using Rails 2.3.5 + jQuery)

    Read the article

  • Ruby: Why is Array.sort slow for large objects?

    - by David Waller
    A colleague needed to sort an array of ActiveRecord objects in a Rails app. He tried the obvious Array.sort! but it seemed surprisingly slow, taking 32s for an array of 3700 objects. So just in case it was these big fat objects slowing things down, he reimplemented the sort by sorting an array of small objects, then reordering the original array of ActiveRecord objects to match - as shown in the code below. Tada! The sort now takes 700ms. That really surprised me. Does Ruby's sort method end up copying objects about the place rather than just references? He's using Ruby 1.8.6/7. def self.sort_events(events) event_sorters = Array.new(events.length) {|i| EventSorter.new(i, events[i])} event_sorters.sort! event_sorters.collect {|es| events[es.index]} end private # Class used by sort_events class EventSorter attr_reader :sqn attr_reader :time attr_reader :index def initialize(index, event) @index = index @sqn = event.sqn @time = event.time end def <=>(b) @time != b.time ? @time <=> b.time : @sqn <=> b.sqn end end

    Read the article

  • Best practice to structure large html-based project

    - by AntonAL
    I develop Rails based website, enjoying using partials for some common "components" Recently, i faced a problem, that states with CSS interference. Styles for one component (described in css) override styles for another components. For example, one component has ... <ul class="items"> ... and another component has it too. But that ul's has different meaning in these two components. On the other hand, i want to "inherit" some styles for one component from another. For example: Let, we have one component, called "post" <div class="post"> <!-- post's stuff --> <ul class="items"> ... </ul> </div And another component, called "new-post": <div class="new-post"> <!-- post's stuff --> <ul class="items"> ... </ul> <!-- new-post's stuff --> <div class="tools">...</div> </div Post and new-post have something similar ("post's stuff") and i want to make CSS rules to handle both "post" and "new-post" New post has "subcomponents", for example - editing tools, that has also: <ul class="items"> This is where CSS rules starting to interfer - some rules, targeted for ul.items (in post and new-post) applies subcomponent of new-post, called "tools" On the one hand - i want to inherit some styles On the other hand, i want to get better incapsulation What are the best practices, to avoid such kind of problems ?

    Read the article

  • Why are symbols not frozen strings?

    - by Alex Chaffee
    I understand the theoretical difference between Strings and Symbols. I understand that Symbols are meant to represent a concept or a name or an identifier or a label or a key, and Strings are a bag of characters. I understand that Strings are mutable and transient, where Symbols are immutable and permanent. I even like how Symbols look different from Strings in my text editor. What bothers me is that practically speaking, Symbols are so similar to Strings that the fact that they're not implemented as Strings causes a lot of headaches. They don't even support duck-typing or implicit coercion, unlike the other famous "the same but different" couple, Float and Fixnum. The mere existence of HashWithIndifferentAccess, and its rampant use in Rails and other frameworks, demonstrates that there's a problem here, an itch that needs to be scratched. Can anyone tell me a practical reason why Symbols should not be frozen Strings? Other than "because that's how it's always been done" (historical) or "because symbols are not strings" (begging the question). Consider the following astonishing behavior: :apple == "apple" #=> false, should be true :apple.hash == "apple".hash #=> false, should be true {apples: 10}["apples"] #=> nil, should be 10 {"apples" => 10}[:apples] #=> nil, should be 10 :apple.object_id == "apple".object_id #=> false, but that's actually fine All it would take to make the next generation of Rubyists less confused is this: class Symbol < String def initialize *args super self.freeze end (and a lot of other library-level hacking, but still, not too complicated) See also: http://onestepback.org/index.cgi/Tech/Ruby/SymbolsAreNotImmutableStrings.red http://www.randomhacks.net/articles/2007/01/20/13-ways-of-looking-at-a-ruby-symbol Why does my code break when using a hash symbol, instead of a hash string? Why use symbols as hash keys in Ruby? What are symbols and how do we use them? Ruby Symbols vs Strings in Hashes Can't get the hang of symbols in Ruby

    Read the article

  • What tasks aren't easy for PHP, ColdFusion and ASP?

    - by boost
    PHP, ColdFusion, and ASP (among many others) are usually sold on their strengths. What are their weaknesses? If one were to develop a niche product to handle the things that these products weren't so good at, what should it focus on? EDIT I'm trying to figure out what things PHP etc are bad at. They're all good at doing the nuts and bolts stuff, if one is looking with a bottom-to-top mindset. I'm thinking a little more globally, more top-to-bottom; what's difficult to achieve in PHP/ASP/CF without thousands of lines of code and twenty minutes of server time? EDIT Suppose company A comes up to you and says, "We want you to do x in PHP." What values of x will cause you to say, "Forget it, buddy, no one in their right mind would use PHP for that"? (swap PHP in the above quote for your favourite tool) EDIT Have we got to the point where everyone's needs can be met with PHP frameworks, Rails and ... er ... Java?

    Read the article

  • how does one _model_ data from relational databases in clojure ?

    - by sandeep
    I have asked this question on twitter as well the #clojure IRC channel, yet got no responses. There have been several articles about Clojure-for-Ruby-programmers, Clojure-for-lisp-programmers.. but what is the missing part is Clojure for ActiveRecord programmers . There have been articles about interacting with MongoDB, Redis, etc. - but these are key value stores at the end of the day. However, coming from a Rails background, we are used to thinking about databases in terms of inheritance - has_many, polymorphic, belongs_to, etc. The few articles about Clojure/Compojure + MySQL (ffclassic) - delve right into sql. Of course, it might be that an ORM induces impedence mismatch, but the fact remains that after thinking like ActiveRecord, it is very difficult to think any other way. I believe that relational DBs, lend themselves very well to the object-oriented paradigm because of them being , essentially, Sets. Stuff like activerecord is very well suited for modelling this data. For e.g. a blog - simply put class Post < ActiveRecord::Base has_many :comments end class Comment < ActiveRecord::Base belongs_to :post end How does one model this in Clojure - which is so strictly anti-OO ? Perhaps the question would have been better if it referred to all functional programming languages, but I am more interested from a Clojure standpoint (and Clojure examples)

    Read the article

  • Executing logic before save or validation with EF Code-First Models

    - by Ryan Norbauer
    I'm still getting accustomed to EF Code First, having spent years working with the Ruby ORM, ActiveRecord. ActiveRecord used to have all sorts of callbacks like before_validation and before_save, where it was possible to modify the object before it would be sent off to the data layer. I am wondering if there is an equivalent technique in EF Code First object modeling. I know how to set object members at the time of instantiation, of course, (to set default values and so forth) but sometimes you need to intervene at different moments in the object lifecycle. To use a slightly contrived example, say I have a join table linking Authors and Plays, represented with a corresponding Authoring object: public class Authoring { public int ID { get; set; } [Required] public int Position { get; set; } [Required] public virtual Play Play { get; set; } [Required] public virtual Author Author { get; set; } } where Position represents a zero-indexed ordering of the Authors associated to a given Play. (You might have a single "South Pacific" Play with two authors: a "Rodgers" author with a Position 0 and a "Hammerstein" author with a Position 1.) Let's say I wanted to create a method that, before saving away an Authoring record, it checked to see if there were any existing authors for the Play to which it was associated. If no, it set the Position to 0. If yes, it would find set the Position of the highest value associated with that Play and increment by one. Where would I implement such logic within an EF code first model layer? And, in other cases, what if I wanted to massage data in code before it is checked for validation errors? Basically, I'm looking for an equivalent to the Rails lifecycle hooks mentioned above, or some way to fake it at least. :)

    Read the article

  • passenger won't spawn more than 6 instances despite passenger_max_pool_size = 30

    - by mrD
    I have some problems with passenger + nginx and hope someone might be able help me and direct me in the right direction. I've set the passenger_max_pool_size to 30 but passenger never spawns more than 6 instances. I'm loading a webpage that uses ajax to load 30 sub pages from the server but because passenger only spawns 6 instances they are queued. What makes me confused is that Waiting on global queue is 0 but I can see in my browser that everything gets queued. When the first 6 ajax requests are done the next 6 starts loading. What am I missing? :) This is the output from passenger-status (I had about 24 requests in the browser waiting for response from the server when I checked this status) ----------- General information ----------- max = 30 count = 6 active = 6 inactive = 0 Waiting on global queue: 0 ----------- Domains ----------- /srv/rails/production/current: PID: 28428 Sessions: 1 Processed: 42 Uptime: 5m 43s PID: 28424 Sessions: 1 Processed: 23 Uptime: 5m 43s PID: 28422 Sessions: 1 Processed: 7 Uptime: 5m 43s PID: 28420 Sessions: 1 Processed: 22 Uptime: 6m 0s PID: 28426 Sessions: 1 Processed: 39 Uptime: 5m 43s PID: 28430 Sessions: 1 Processed: 7 Uptime: 5m 43s These are my passenger related settings in nginx.conf http { passenger_root /opt/ruby/lib/ruby/gems/1.8/gems/passenger-2.2.11; passenger_ruby /opt/ruby/bin/ruby; passenger_max_pool_size 30;

    Read the article

< Previous Page | 284 285 286 287 288 289 290 291 292  | Next Page >