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Page 2224 of 2547
Introduction to URLSearchParams API in Node.js
Node is an open source project that is used to create dynamic web applications. The URLSearchParams API is an interface. It defines different utility that is required to work with the query string of the URL.In this article, we will discuss the four different constructors of URLSearchParams that can be used as per the requirement.new URLSearchParams()This is a no argument constructor and therefore only used to initialize a new Empty URLSearchParams() object.Syntaxvar params = new URLSearchParams();new URLSearchParams(string)This constructor can accept a string as an input parameter along with instantiating a new URLSearchParams object.Syntaxconst params = new URLSearchParams('firstName=pqr & lastName=xyz'); ...
Read MoreIntroduction to Sequelize in NodeJS
Sequelize follows a promise-based Node.js ORM structure for different databases like – Postgres, MySQL, MariaDB, SQLite and Microsoft SQL Server. Sequelize have multiple features which makes it easy to implement and use.Some of the main features of sequelize are as follows −Sequelize is a third-party package.It uses an Object-Relational Mapping to map objects. That's why its called an ORM.Sequelize supports solid transaction support along with eager and lazy loading concept.It can also perform read replication on databases.Sequelize follows standardization, which means it has a single schema definition in the code. Standardization makes the schema easy to read and understand along ...
Read MoreImage Processing with NodeJS JIMP
JIMP, also known as JavaScript Image Manipulation Program, is an image processing library for Node written in JavaScript with no other dependency. It allows the user to easily manipulate the and transform the images into any required shape, format, dimnesion or style. It can also be used for optimizing images to minimize the file size, ensuring high visualquality or reducing the bandwidth.Using JIMP, you can resize and crop images, convert them to the format as needed and also apply different filters and affects. Following are image formats that are supported by NodeJS JIMP −@jimp/jpeg@jimp/png@jimp/bmp@jimp/tiff@jimp/gifInstallationSetup Environment -npm init -yInstalling Dependecy -npm ...
Read MoreensureSymlink() function in fs-extra - NodeJS
Introduction to Async ensureSymlink()This method will ensure whether the symlink exists or not. It will create the directory structure if it does not exist.SyntaxcreateSymlink(srcPath, destPah[, type] [, callback])ParameterssrcPath – The source path of the file.destPath – Destination path of the file.type – This parameter is only available on Windows and ignored on other platforms.The possible values for this parameter is dir, file or junction.callback – This function will give a callback if any error occurs.ExampleCheck that fs-extra is installed before proceeding; if not, install fs-exra.You can use the following command to check whether fs-extra is installed or not.npm ls fs-extraCreate ...
Read MoreIntroduction to ensureFileSync() in NodeJS
This method is used to ensure that a file exists at the given location by using a sync process. The response will only be given after the processing is completed. If the files that is ensured to be created is not present or the respective directories are not present, these directories and files are created. If the file already exists, it is not modified or no change is made.SyntaxensureFileSync(file)Parametersfile – This is a string paramter which will hold the location of the file that needs to be ensured.ExampleCheck that fs-extra is installed before proceeding; if not, install fs-exra.You can use ...
Read MoreensureFile() function in fs-extra - NodeJS
Introduction to Async ensureFile()This method is used to ensure that a file exists at the given location. If the files that is ensured to be created is not present or the respective directories are not present, these directories and files are created. If the file already exists, it is not modified or no change is made.SyntaxensureFile(file, [, callback])Parametersfile – String parameter which will contain name of the file and its location that needs to be ensured.callback – This function will give a callback if any error occurs.Example 1Check that fs-extra is installed before proceeding; if not, install fs-exra.You can use ...
Read MoreIntroduction to Sync emptyDir() in NodeJS
This method is used to empty a directory whether it is empty or not with a sync process. If the directory is not empty, it will remove all its contents and empty it. A new empty directory is created if the directory does not exist.SyntaxemptyDirSync(dir)Parametersdir – This is a string paramter which will hold the location of the directory structure.Example 1Check that fs-extra is installed before proceeding; if not, install fs-exra.You can use the following command to check whether fs-extra is installed or not.npm ls fs-extraCreate a syncEmptyDir.js and copy-paste the following code snippet into that file.Now, run the following ...
Read MoreEmptyDir() function in fs-extra - NodeJS
Introduction to Async emptyDir()This method is used to empty a directory whether it is empty or not. If the directory is not empty it will remove all its contents and empty it. A new empty directory is created if the directory does not exist.SyntaxemptyDir(dir, [, callbacks])Parametersdir – This is a string paramter which will hold the location of the directory structure.callback – This function will give a callback if any error occurs.Example 1Check that fs-extra is installed before proceeding; if not, install fs-exra.You can use the following command to check whether fs-extra is installed or not.npm ls fs-extraCreate a asyncEmptyDir.js ...
Read MoreDropping a MySQL Table using NodeJS
You can delete an existing table from MySql Database using the "DROP TABLE" statement in Node. Sometimes, we need to delete the whole table, though in corporates it is always advised to archive the tables which are not in used instead of deleting them.While deleting a table, we have two scenarios −Deleting a table if it exists, else throw an errorDeleting the table whether it exists or not.We will discuss both the scenarios here.Before proceeding, please check the following steps are already executed −mkdir mysql-testcd mysql-testnpm init -ynpm install mysqlThe above steps are for installing the Node - mysql dependecy ...
Read MoreDifference between process.cwd & _ _dirname in NodeJS
NodeJS is a JavaScript runtime environment that was built on top of Chrome's V8 engine. The traditional use of JavaScript is to be executed in browsers, but with Node.JS we can execute JavaScript other than browsers like servers, hardware devices, etc.process.cwd()The process object lies under the global object known as 'global'. This method provides information about the current process of Node.js. It also provides control over the same. cwd refers to the current working directory of the same. Therefore, process.cwd returns the working directory on which execution is taking place currently.__dirnameThis is a local module that will return the directory ...
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