Mean Stack Goodness

Wednesday, October 29, 2014

Download and install node.js


Download and install mongodb


npm install these modules into node_modules folder


To execute this JAVASCRIPT file in the node environment, execute node intro.js from command prompt


Let's create a module, in module folder create folder wordcop and add JAVASCRIPT file wordcoptext.js, this code verifies an input and changes words form the array to a sequence of hashes, the export command tells node which properties are to be exported, with require statement, JAVASCRIPT file gets loaded and these fields can be accessed from the module, basically the public api


The package.json file provides information about the module, the main property specifies the JAVASCRIPT executable to run, the engine specifies that this module will run with any version of node, repository is for online location where npm can pull the repository from


Create the package, navigate to the wordcop folder, execute npm pack command, this builds module and creates tgz file


Install wordcop package in readtext folder using npm install, it is now installed in nodemodules folder


Implement wordcop package with a require, bring in the package and assign it to a variable, then log some calls to the api, execute node readtext.js in the console


The function takes in a string and a callback function, callback event handler is implemented, first display log the element, then invoke process.nexttick, nexttick will queue up the request, whenever ready node event handler will pick it up and execute the callback function that was passed in and pass in the element, execute node in the command prompt, first the elements are logged and then the callback is processed, this is the node event callback model


Events and listeners part 1


Implementation and usage


Read and write to files, file io, load fs, nodes file system module, interact with files, write some data to the first file, hook into finish event, pipe method writes from one stream into the next, on readable and end events log data to the console, execute fileo.js in the command prompt, same principle applies to socket stream or httprequest


Start the mongodb database


Open another command prompt and start the mongo shell


Create new database using use command, this creates a handle, the new database isn't actually created untill collections and documents are added


To find documents in the collection use find command, none are returned since none created


Insert a document like this


Execute a find on the collection, view the document, an id for the object is automatically created


Insert multiple documents inside of an array


Do a find, view a total of four documents in the collection, just added three


Create a lunch collection and insert a document, insert another one and do a find to view the documents in the collection


Use findone to display first document found


Specify query object, only documents with result of thirteen


Query operators are prefixed with a dollar sign, this specifies a resultset of less than eleven


Use in to find from values in an array


Use and to find on multiple query operators in a single find operation


Assign cursor object to a variable, iterate over it and printjson the current document


The cursor variable holds all documents in the collection, call a count on it, get four


Limit limits to the number passed in, it grabs the first two documents


Find takes in as first parameter a query, in this case empty, second parameter the field to include or exclude, one means include, zero means exclude


In find clause, set id to zero, just retrieve the name field


Get distinct values for result field


Update document, change name, add a field and decrement a field


Update multiple documents, decrement score by 5, multi true applies to all documents


Find one object by name assign it to the doc variable, type doc to display it on screen, set result for doc object, type in doc view result has been updated, use save method on collection to persist to database, pass in object to be saved, view find with filter, result has been updated


Remove documents from collection using remove method


Remove all documents from collection, pass in an empty object into remove method


Drop a collection using drop method on collection


Drop database using dropdatabase method on database object


Default Success Warning Important Info Inverse
B S W I ? O