Tutorial by Examples: c

Imagine many users all running a web application that is trying to increment a counter in the database. Each user must read the current count, add one and write out the updated value. To make sure no one reads the counter while someone else is is adding one we use a transaction: ref.transaction(fun...

Publishers and subscribers don't need to know each other. They simply communicate with the help of message queues. (function () { var data; setTimeout(function () { data = 10; $(document).trigger("myCustomEvent"); }, 2000); ...

/** * Remove the automatic line breaks from content and excerpts. * * @since 1.0.0 */ function remove_content_auto_line_breaks() { // Remove the auto-paragraph and auto-line-break from the content remove_filter( 'the_content', 'wpautop' ); // Remove the auto-paragraph and a...

Every Heroku app runs in at least two environments: on Heroku (we’ll call that production) and on your local machine (development). If more than one person is working on the app, then you’ve got multiple development environments - one per machine, usually. Usually, each developer will also have a te...

Let's start using ExtJS to build a simple web application. We will create a simple web application which will have only one physical page (aspx/html). At a minimum, every ExtJS application will contain one HTML and one JavaScript file—usually index.html and app.js. The file index.html or your defa...

For a C-style function call, e.g. plus(a, b); // Parentheses surrounding only the arguments, comma separated Then the equivalent Haskell code will be (plus a b) -- Parentheses surrounding the function and the arguments, no commas In Haskell, parentheses are not explicitly required for functi...

In the previous example, we didn't end up needing the parentheses, because they did not affect the meaning of the statement. However, they are often necessary in more complex expression, like the one below. In C: plus(a, take(b, c)); In Haskell this becomes: (plus a (take b c)) -- or equivale...

In Haskell, functions can be partially applied; we can think of all functions as taking a single argument, and returning a modified function for which that argument is constant. To illustrate this, we can bracket functions as follows: (((plus) 1) 2) Here, the function (plus) is applied to 1 yiel...

As another example, we have the function map, which takes a function and a list of values, and applies the function to each value of the list: map :: (a -> b) -> [a] -> [b] Let's say we want to increment each value in a list. You may decide to define your own function, which adds one to...

Reagent is an interface between ClojureScript and react. It allows you to define efficient React components using nothing but plain ClojureScript functions and data, that describe your UI using a Hiccup-like syntax. Example:- (defn sample-component [] [:div [:p "I am a component!"...

DB backup Database backup is a must before starting any Dynamics CRM upgrade process. This is mandatory as to always have the option to rollback in case of any major roadblock. Wrong Estimation DO NOT underestimate the work involved in a CRM Upgrade process. Audit your current Microsoft Dynamics...

Now, here are some common pitfalls which might come along your way when upgrading your Dynamics CRM system. The organisation database selected for the import is a different version than the organisation database that is currently deployedCRM Organization Database To fix this issue, we need to in...

Go to File -> Project Structure -> Modules. Add new Hibernate module. Right click on the desired module -> Add -> Hibernate. Select the newly created Hibernate configuration option, and click the (+) sign in the right pane to create hibernate.cfg.xml file. Go to File -> Project ...

ScriptAnalyzer ships with sets of built-in preset rules that can be used to analyze scripts. These include: PSGallery, DSC and CodeFormatting. They can be executed as follows: PowerShell Gallery rules To execute the PowerShell Gallery rules use the following command: Invoke-ScriptAnalyzer -Path /...

To run the script analyzer against a single script file execute: Invoke-ScriptAnalyzer -Path myscript.ps1 This will analyze your script against every built-in rule. If your script is sufficiently large that could result in a lot of warnings and/or errors. To run the script analyzer against a w...

var record = nlapiCreateRecord('customrecord_ennveeitissuetracker', { recordmode: 'dynamic' }); nlapiLogExecution('DEBUG', 'record', record); record.setFieldValue('custrecord_name1', name); record.setFieldValue('custrecord_empid', id); record.setFieldValue('custrecord_contactno', contactno); re...

SET v_column_definition := CONCAT( v_column_name ,' ',v_column_type ,' ',v_column_options ); SET @stmt := CONCAT('ALTER TABLE ADD COLUMN ', v_column_definition); PREPARE stmt FROM @stmt; EXECUTE stmt; DEALLOCATE PREPARE stmt;

Object1 := nil; Object2 := nil; try Object1 := TMyObject.Create; Object2 := TMyObject.Create; finally Object1.Free; Object2.Free; end; If you do not initialize the objects with nil outside the try-finally block, if one of them fails to be created an AV will occur on the finally bl...

The pack() geometry manager organizes widgets in blocks before placing them in the parent widget. It uses the options fill, expand and side. Syntax widget.pack(option) Fill Determines if the widget keeps the minimal space needed or takes up any extra space allocated to it. Attributes: NONE (defa...

The place() manager organises widgets by placing them in a specific position in the parent widget. This geometry manager uses the options anchor, bordermode, height, width, relheight, relwidth,relx, rely, x and y. Anchor Indicates where the widget is anchored to. The options are compass directions...