Tutorial by Examples: en

A frequent reason why your read operation may not work is because your security rules reject the operation, for example because you're not authenticated (by default a database can only be accessed by an authenticated user). You can see these security rule violations in the logcat output. But it's e...

(ns so-doc.events (:require [goog.dom :as dom] [goog.events :as events])) (defn handle-click [event] ;an event object is passed to all events (js/alert "button pressed")) (events/listen (dom/getElement "button"); This is the dom element the event comes fro...

Large scale applications often need different properties when running on different environments. we can achieve this by passing arguments to NodeJs application and using same argument in node process to load specific environment property file. Suppose we have two property files for different enviro...

using UIKit; using AddressBookUI; using Xamarin.Forms; using Xamarin.Forms.Platform.iOS; using contact_picker; using contact_picker.iOS; [assembly: ExportRenderer (typeof(ChooseContactPage), typeof(ChooseContactRenderer))] namespace contact_picker.iOS { public partial class Choose...

Okay it took me about a day to figure it out so here I am posting the steps I followed to get my Database First working in a Class Project (.NET Core), with a .NET Core Web App. Step 1 - Install .NET Core Make Sure you are using .NET Core not DNX (Hint: You should be able to see the .NET Core opti...

To automatically install bower and its components, one must Specify the bower dependency in package.json: "dependencies": { "bower": "^1.7.9" } Use scripts to execute a postinstall command "scripts": { "postinstall": "./...

Sending data back to the parent, to do this we simply pass a function as a prop from the parent component to the child component, and the child component calls that function. In this example, we will change the Parent state by passing a function to the Child component and invoking that function ins...

Logs are very important. Recreate an error context can be sometimes very painful due to the lack of information about how and when the error occurred. This example shows: How to add user's data in the error logs How to add post parameters sent when an error occurred How to use WebPr...

//Before: antipattern 3 global variables var setActivePage = function () {}; var getPage = function() {}; var redirectPage = function() {}; //After: just 1 global variable, no function collision and more meaningful function names var NavigationNs = NavigationNs || {}; N...

Let us assume we have the following two DataFrames: In [7]: df1 Out[7]: A B 0 a1 b1 1 a2 b2 In [8]: df2 Out[8]: B C 0 b1 c1 The two DataFrames are not required to have the same set of columns. The append method does not change either of the original DataFrames. Inst...

The IIF statement can be used in expressions to screen for division by zero: =IIF(Fields!PossibleZero.Value=0,0,Fields!Denominator.Value/IIF(Fields!PossibleZero.Value=0,1,Fields!PossibleZero.Value)) SSRS does not short circuit IIF arguments. Therefore, using a single IIF function to screen for ...

Lets say you have a simple ApiController like this: [HttpGet] [Route("test")] public dynamic Test() { dynamic obj = new ExpandoObject(); obj.prop1 = "some string"; obj.prop2 = 11; obj.prop3 = "another string"; ...

This example shows how to take image and display it correctly on the Android device. Firstly we have to create sample application with one button and one imageview. Once user clicks on the button camera is launched and after user selects picture it will be displayed with the proper orientation on ...

To be able do deal with form events, it's important to attach the request, that is send to a controller action after submitting a form, to the form created in that action. public function registerAction(Request $request) { $data = new ExampleObject(); $form = $this->createForm(Example...

wxPython Phoenix is the latest version of wxPython, (currently Sept 2016 without an official release). It supports both Python 2 and Python 3. You can download a snapshot build (i.e. a Python wheel) for your platform and Python version here. wxPython Phoenix utilizes a largely automated mechanism ...

You can use concatenation to join strings "end to end" while outputting them (with echo or print for example). You can concatenate variables using a . (period/dot). // String variable $name = 'Joel'; // Concatenate multiple strings (3 in this example) into one and echo it once done. ...

Add the necessary dependencies to the project POM (mybatis, and mybatis-spring): <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>x.x.x</version> </dependency> <dependency> <group...

A1:A4 have A,B,C,D. B1 have the following formula: =ARRAYFORMULA({A1:A4,ROW(A1:A4)}) Result ABC1AA12BB23CC34DD4

The local configuration of sane is inside /etc/saned.d /etc/sane.d/dll.conf # /etc/sane.d/dll.conf - Configuration file for the SANE dynamic backend loader # # Backends can also be enabled by configuration snippets under # /etc/sane.d/dll.d directory -- packages providing backends should drop...

Sometimes, it can be useful to import functions and structs relatively without having to use something with its absolute path in your project. To achieve this, you can use the module super, like so: fn x() -> u8 { 5 } mod example { use super::x; fn foo() { println!(...