A simple and powerful generic javascript collection (List, Stack, Queue, FixedQueue) including power of LINQ for Javascript, node.js
npm install jscollection
List.sequentialExe: For better error handling, execute unlimited functions sequentially & asynchronously using sequentialExe
* var myList = new List();
* myList.add(item) // Add an item in collection
* myList.addRange(arrayOfItems) // Add multiple items in collection
* myList.insertAt(index, item); // Insert an item at a given position
* myList.removeAt(index); // Remove an item from a given position also returns the deleted item
* myList.remove(item) // Remove an item from collection also returns the deleted item
* myList.removeLast() // Remove the last item from collection also returns the deleted item
* myList.removeAt(index) // Remove an item at specific index from collection also returns the deleted item
* myList.first() // Get the first item from the collection, throws Index out of range exception if empty
* myList.last() // Get the last item from the collection, throws Index out of range exception if empty
* myList.count() // Get the size of the collection
* myList.any() // Is there any items present in collection? returns true/false
* myList.avg() // Calculate average of numeric values present in collection
* myList.sum() // Calculate sum of numeric values present in collection
* myList.reverse() // Reversing the elements in an array
* myList.sort() // Sort items in collection
* myList.sort(compareFunction) // Sort items in collection | http://www.w3schools.com/jsref/jsref_sort.asp#compareFunction* myList.each(function) // Traverse the collection
* myList.eachReverse(function) // Traverse the collection in reverse way
* myList.eachAsync(function(item,index,nextCallback){}) // traverse the collection and perform asynchronous operations for each
* myList.eachAsyncReverse(function(item,index,nextCallback){}) // traverse the collection and perform asynchronous operations for each in reverse direction* myList.select(selector function)
* myList.selectMulti(selector function)
* myList.where(selector function)
* myList.groupby(selector function)
* myList.orderByAsc(comparator function)
* myList.orderByDesc(comparator function)
* myList.unique()
* myList.top(count)
* myList.bottom(count)
* myList.range(fromIndex,toIndex)Static Functions | When you don't really need to convert an array to a List, So first argument of the functions below will be your array.
* List.extend(myArray); // Static Function | Extends an array to List in order to avail features of List
* List.toList(myArray, isSelectKeys);
* List.toList(myObject, isSelectKeys); // Creates new List from an Array or values list of a normal object, pass isSelectKeys as true if you want to consider keys
* List.printInConsole(); // Prints the data present in list in console | you can use it for debug purpose
* List.each(myArray, function) // Traverse the collection
* List.eachReverse(myArray, function) // Traverse the collection in reverse way
* List.eachAsync(myArray, function(item,index,nextCallback){}) // traverse the collection and perform asynchronous operations for each
* List.eachAsyncReverse(myArray, function(item,index,nextCallback){}) // traverse the collection and perform asynchronous operations for each in reverse direction####Creating list
var list = new List([1, 2, 3, 4]);
// OR
var list = new List();
list.addRange([1, 2, 3, 4]);####Adding Item to List
var list = new List();
list.add(1);
list.add(2);
list.add(3);
list.add(4);####Lets add some objects
// Lists of students as an example
var list = new List([{name:"Jhon", marks: 80, class: 1},
{name:"Micle", marks: 91, class: 1},
{name:"Ritu", marks: 50, class: 2},
{name:"Sonia", marks: 50, class: 2}
]);####Removing Item from List using remove(), removeLast(), removeAt() and clear()
list.remove(item);
var removedItem = list.removeLast(); // Removes the last item from collection
var removedItem = list.removeAt(index); // Removes an item present at index####Delete or clear all items from collection using clear()
list.clear();####Traversing a collection using each, eachReverse
list.each(function(item, indexOfItem){
console.log(item.name +':' + item.marks);
});
list.eachReverse(function(item, indexOfItem){
console.log(item.name +':' + item.marks);
}); list.eachAsync(function(item, indexOfItem, next){
console.log(item.name +':' + item.marks);
next();
});
list.eachAsyncReverse(function(item, indexOfItem, previous){
console.log(item.name +':' + item.marks);
previous();
});####Break the loop while traversing through collection
list.each(function(item, indexOfItem){
console.log(item.name +':' + item.marks);
if(indexOfItem == 3) return false; // Returning false will break the loop
});####Perform select query by key using select
var names = list.select("name");####Perform select query by selector function
var names = list.select(function(t){return t.name;});####Perform where query (Select names of the student where markes >= 80)
var names = list.where(function(t){return (t.marks >= 80);}).select('name');####Perform groupby query in javascript
/* According to above data set our result will be creting two groups.
One group where class=1 and another for class=2 */
var groups = list.groupby('class'});
// OR
var groups = list.groupby(function(t){return t.class;}); List.exeAsync(function insertIntomongo(next){
// Do operation in mongo
next(datareturnedFromMongo); // once you are done call next
}, function insertIntoOracle(next, datareturnedFromMongo){
// Do operation in oracle
next(datareturnedFromOracle); // // once you are done call next
}, function onDone(next, datareturnedFromOracle){
// final call back here
});For better error handling, execute unlimited functions sequentially & asynchronously using sequentialExe
List.sequentialExe(function insertIntomongo(next){
// Do operation in mongo
next(error, datareturnedFromMongo); // once you are done call next
}, function insertIntoOracle(next, datareturnedFromMongo){
// Do operation in oracle
next(error, datareturnedFromOracle); // // once you are done call next
}, function onDone(error){
// final call back here
// Any error in any function will skip next function and directly comes to onDone function
}); List.parallelExe(function insertIntomongo(next){
// Do operation in mongo
next(datareturnedFromMongo); // once you are done call next
}, function insertIntoOracle(next, datareturnedFromMongo){
// Do operation in oracle
next(datareturnedFromOracle); // // once you are done call next
}, function onDone(next, results){
// final call back here
// err is nothing but the latest occurred error. results will contain output from all the executed functions
So results = [[mongoError, datareturnedFromMongo],[oracleError, datareturnedFromOracle]];
}); list.loopAsync(N, function callMeNTimes(index, next){
console.log('Called :' + index);
next(err, break); // you can pass break = true to break the loop
}, onDone(err){
// if break is called or any error occurred then onDone function will be called
});npm test install list "chai": "^3.5.0", "mocha": "^2.5.1"
@somnathpanja (somnathpanja@gmail.com)
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