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What is the difference between ng-if and ng-show/ng-hide

... ngIf The ngIf directive removes or recreates a portion of the DOM tree based on an expression. If the expression assigned to ngIf evaluates to a false value then the element is removed from the DOM, otherwise a clone of the element is reinserted into the DOM. <!-- when $scope.myValue is trut...
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Abstract functions in Swift Language

...cept of abstract in Swift (like Objective-C) but you can do this : class BaseClass { func abstractFunction() { preconditionFailure("This method must be overridden") } } class SubClass : BaseClass { override func abstractFunction() { // Override } } ...
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Can you get DB username, pw, database name in Rails?

...ain the necessary information from it: config = Rails.configuration.database_configuration host = config[Rails.env]["host"] database = config[Rails.env]["database"] username = config[Rails.env]["username"] password = config[Rails.env]["password"] See the documentation for Rails::Configurati...
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What is included in JCenter repository in Gradle?

...n Central. Also I find a good compare at https://www.jfrog.com/knowledge-base/why-should-i-use-jcenter-over-maven-central/ ( unfortunately the link seems dead but some useful hints are here) jcenter is the public repository hosted at bintray that is free to use for open source library publis...
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Capitalize the first letter of both words in a two word string

... The base R function to perform capitalization is toupper(x). From the help file for ?toupper there is this function that does what you need: simpleCap <- function(x) { s <- strsplit(x, " ")[[1]] paste(toupper(substrin...
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SQL Joins Vs SQL Subqueries (Performance)?

...f it was possible). But when you have a Group by on a well indexed column (based on its cardinality) then it will be much faster. So it really depends on the situation. – Alix May 17 at 14:22 ...
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Responsive css background images

... If you want the same image to scale based on the size of the browser window: background-image:url('../images/bg.png'); background-repeat:no-repeat; background-size:contain; background-position:center; Do not set width, height, or margins. EDIT: The previous...
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How do I create a variable number of variables?

...s that the only difference in each of those lines is a number that changes based on a rule, and decides to use a loop. However, they get stuck on how to dynamically create those variable names, and may try something like this: for i in range(10): my_calculator.('button_%d' % i) = tkinter.Button...
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What does “program to interfaces, not implementations” mean?

...er. EDIT I have updated the example above and added an abstract Speaker base class. In this update, I added a feature to all Speakers to "SayHello". All speaker speak "Hello World". So that's a common feature with similar function. Refer to the class diagram and you'll find that Speaker abstract ...
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How to convert IPython notebooks to PDF and HTML?

... HTML. List of current available profiles: $ ls -l1 profile|cut -d. -f1 base_html blogger_html full_html latex_base latex_sphinx_base latex_sphinx_howto latex_sphinx_manual markdown python reveal rst Give you the existing profiles. (You can create your own, cf future doc, ./nbconvert2.py --hel...