AWS API Gateway
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Angular JS Service
July 19, 2015 Leave a comment
Introduction
in previous post we concentrated on how to consume json data from server. i.e. user provide stock symbol in search box and and click on search button.
in this post we will add one more functionality i.e. adding stock to watch list(although stock data is not updated but we will check how to auto refresh this data in next post.)
Need for Service
Irrespective of programming language service provide following benefits
- writing business logic
- writing common code which can be reused by multiple controllers
apart from this in angular js it provide one more benefit i.e. caching of data which can be accessed by multiple controllers, giving http call.
UI
User provide stock symbol and click search.
user click on add to watch list system will add stock in watch list.
In view(html) use
- stockSearchWatchListController.js :-JS for searching stock and adding it to watchlist
- yahooFinanceYQLAPIService.js :-
- Service for communicating with remote server on http.
- Caching common data required for searching and watchlist activities.
- we are using google font
<script src=”https://ajax.googleapis.com/ajax/libs/angularjs/1.3.15/angular.min.js”></script>
<script src=”stockSearchWatchListController.js”></script>
<script src=”yahooFinanceYQLAPIService.js”></script>
<link href=’http://fonts.googleapis.com/css?family=Amaranth:400,400italic’ rel=’stylesheet’ type=’text/css’>
<style>
body {font-family: ‘Amaranth’, sans-serif;}
table, th , td {border: 1px solid grey;border-collapse: collapse;padding: 5px;}
table tr:nth-child(even) {background-color: #f1f1f1;}
table tr:nth-child(odd) {background-color: #ffffff;}
table th {background-color: #A0AFD8;color:F9F7F7;}
button {background-color: #A0AFD8; border-radius: 5px;font-style: italic; text-decoration: underline;}
input{border-radius: 5px; font-style: italic;}
</style>
Create module in stockSearchWatchListController.js
//define module named stockModule
var stockModule = angular.module(‘stockModule’,[]);
Create yahooFinanceYQLAPIService and register it in module
Create default implementation of
var yahooFinanceYQLAPIService=function($http){
//default implementation
};
Register service with module.
var module=angular.module(“stockModule”);
module.factory(“yahooFinanceYQLAPIService”,yahooFinanceYQLAPIService);
stockSearchWatchListController.js
//define module named stockModule
var stockModule = angular.module(‘stockModule’,[]);
//replace $http with yahooFinanceYQLAPIService since yahooFinanceYQLAPIService is taking care of http communication
stockModule.controller(‘myStockSeachController’,function($scope,yahooFinanceYQLAPIService){
$scope.getScriptDetails=function(){
console.log(“script details “+$scope.scriptcode);
var response=yahooFinanceYQLAPIService.getScriptsDetails($scope.scriptcode);
response.success(function(data, status, headers, config) {
$scope.scriptDetails=data;
});
response.error(function(data, status, headers, config) {
console.log(“failure “+data+” status “+status+” headers “+headers);
});
};
});
stockModule.controller(‘addStockToWatchListController’,function($scope,yahooFinanceYQLAPIService){
$scope.addToWatchList=function(){
console.log(“adding script to watchList”);
var response=yahooFinanceYQLAPIService.addScriptToWatchList();
if (response === undefined) {
return;
}
response.success(function(data, status, headers, config) {
if(data.query.count!=1){
$scope.scripts=data.query.results.quote;
}else{
var scriptArray=[];
scriptArray.push(data.query.results.quote);
$scope.scripts=scriptArray;
}
});
response.error(function(data, status, headers, config) {
console.log(“failure “+data+” status “+status+” headers “+headers);
});
};
});
yahooFinanceYQLAPIService.js
var yahooFinanceYQLAPIService=function($http){
var latestScriptCode=”;//useful for addScriptToWatchList i.e. shared between both search controller and watchlist controller.
var getScriptsDetails=function(script){
var url=’https://query.yahooapis.com/v1/public/yql’;
var query=’select%20*%20from%20yahoo.finance.quotes%20where%20symbol%20in%20(%22’+’\”+script+’%22)&format=json&diagnostics=true&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys&callback’;
url=url+’?q=’+query;
latestScriptCode=script;
return $http.get(url);
};
var watchListScripts=[];
var addScriptToWatchList=function addScriptToWatchList(){
if(watchListScripts.indexOf(latestScriptCode)>=0){
return;
}
watchListScripts.push(latestScriptCode);
console.log(“watchListScripts:- “+watchListScripts.join());
var url=’https://query.yahooapis.com/v1/public/yql’;
var query=’select%20*%20from%20yahoo.finance.quotes%20where%20symbol%20in%20(%22’+’\”+watchListScripts.join()+’%22)&format=json&diagnostics=true&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys&callback’;
url=url+’?q=’+query;
return $http.get(url);
};
return{
getScriptsDetails:getScriptsDetails,
addScriptToWatchList:addScriptToWatchList
};
};
var module=angular.module(“stockModule”);
module.factory(“yahooFinanceYQLAPIService”,yahooFinanceYQLAPIService);
view(html)
<body ng-app=”stockModule”>
<div ng-controller=”myStockSeachController” align=”center”>
<div>Stock Quote</div>
<div>
<form name=”stockQuoteForm”>
<input type=”text” required placeholder=”scriptcode” class=”form-control” ng-model=”scriptcode”>
<button ng-click=”getScriptDetails()” type=”button” class=”btn btn-primary”>Search</button>
</form>
</div>
<table ng-show=”scriptDetails”>
<thead>
<tr>
<th>Name</th>
<th>symbol</th>
<th>LastTradePriceOnly</th>
<th>Ask</th>
<th>Bid</th>
<th>AverageDailyVolume</th>
<th>Currency</th>
<th>LastTradeDate</th>
<th>LastTradeTime</th>
<th>DaysLow</th>
<th>DaysHigh</th>
<th>YearLow</th>
<th>YearHigh</th>
<th>PE Ratio</th>
</tr>
</thead>
<tbody>
<tr>
<td>{{scriptDetails.query.results.quote.Name}}</td>
<td>{{scriptDetails.query.results.quote.symbol}}</td>
<td>{{scriptDetails.query.results.quote.LastTradePriceOnly}}</td>
<td>{{scriptDetails.query.results.quote.Ask}}</td>
<td>{{scriptDetails.query.results.quote.Bid}}</td>
<td>{{scriptDetails.query.results.quote.AverageDailyVolume}}</td>
<td>{{scriptDetails.query.results.quote.Currency}}</td>
<td>{{scriptDetails.query.results.quote.LastTradeDate}}</td>
<td>{{scriptDetails.query.results.quote.LastTradeTime}}</td>
<td>{{scriptDetails.query.results.quote.DaysLow}}</td>
<td>{{scriptDetails.query.results.quote.DaysHigh}}</td>
<td>{{scriptDetails.query.results.quote.YearLow}}</td>
<td>{{scriptDetails.query.results.quote.YearHigh}}</td>
<td>{{scriptDetails.query.results.quote.PERatio}}</td>
</tr>
</tbody>
</table>
</div>
<div ng-controller=”addStockToWatchListController” align=”center”>
<p>
<button ng-click=”addToWatchList()” type=”button” class=”btn btn-primary”>AddToWatchList</button>
</p>
<div ng-show=”scripts”>
<table>
<thead>
<tr>
<th ng-click=”sortColumn(‘Name’)” >Name</th>
<th ng-click=”sortColumn(‘symbol’)”>symbol</th>
<th ng-click=”sortColumn(‘LastTradePriceOnly’)”>LastTradePriceOnly</th>
<th ng-click=”sortColumn(‘Ask’)”>Ask</th>
<th ng-click=”sortColumn(‘Bid’)”>Bid</th>
<th ng-click=”sortColumn(‘AverageDailyVolume’)”>AverageDailyVolume</th>
<th>Currency</th>
<th ng-click=”sortColumn(‘LastTradeDate’)”>LastTradeDate</th>
<th ng-click=”sortColumn(‘LastTradeTime’)”>LastTradeTime</th>
<th ng-click=”sortColumn(‘DaysLow’)”>DaysLow</th>
<th ng-click=”sortColumn(‘DaysHigh’)”>DaysHigh</th>
<th ng-click=”sortColumn(‘YearLow’)”>YearLow</th>
<th ng-click=”sortColumn(‘YearHigh’)”>YearHigh</th>
<th ng-click=”sortColumn(‘PERatio’)”>PE Ratio</th>
</tr>
</thead>
<tbody>
<tr ng-repeat=”sc in scripts”>
<td>{{sc.Name}}</td>
<td>{{sc.symbol}}</td>
<td>{{sc.LastTradePriceOnly}}</td>
<td>{{sc.Ask}}</td>
<td>{{sc.Bid}}</td>
<td>{{sc.AverageDailyVolume}}</td>
<td>{{sc.Currency}}</td>
<td>{{sc.LastTradeDate}}</td>
<td>{{sc.LastTradeTime}}</td>
<td>{{sc.DaysLow}}</td>
<td>{{sc.DaysHigh}}</td>
<td>{{sc.YearLow}}</td>
<td>{{sc.YearHigh}}</td>
<td>{{sc.PERatio}}</td>
</tr>
</tbody>
</table>
</div>
</div>
</body>
Angular JS HTTP Communication
July 12, 2015 1 Comment
In earlier post we understood just about basic facts about how to configure controller in angular JS. In this post we will concentrate on how to send HTTP requests and consume the JSON response.
Example for HTTP request
We will be using Yahoo’s query API for getting stock details. i.e. https://query.yahooapis.com/v1/public/yql
We need to also attach following query parameters to the above URL.
- q= YQL query (it is SQL like query to fetch details. More information on Yahoo developer network
- format= JSON
- diagnostics=true
- env=store
- Callback
YQL for fetching data for YAHOO (YHOO).
Replacing $scope. scriptcode=YHOO
select * from yahoo.finance.quotes where symbol in (‘+’\”+$scope.scriptcode+’)
Complete URL for getting stock details
var query=’select%20*%20from%20yahoo.finance.quotes%20where%20symbol%20in%20(%22’+’\”+$scope.scriptcode+‘%22)&format=json&diagnostics=true&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys&callback’;
url=url+’?q=’+query;
What we want to do?
We will offer a search facility to the end-user where users can give stock symbol.
When a user provides stock symbol and click search then the system will give call to yahoo server and fetch the response in JSON to display stock details in the following way.
View layer (HTML)
JS and CSS dependency
<script src=”https://ajax.googleapis.com/ajax/libs/angularjs/1.3.15/angular.min.js”></script>
<script src=”angularjsHttpCall.js”></script>
<link href=’http://fonts.googleapis.com/css?family=Amaranth:400,400italic’ rel=’stylesheet’ type=’text/css’>
<style>
body {font-family: ‘Amaranth’, sans-serif;}
table, th , td {border: 1px solid grey;border-collapse: collapse;padding: 5px;}
table tr:nth-child(even) {background-color: #f1f1f1;}
table tr:nth-child(odd) {background-color: #ffffff;}
table th {background-color: #A0AFD8;color:F9F7F7;}
button {background-color: #A0AFD8; border-radius: 5px;font-style: italic; text-decoration: underline;}
input{border-radius: 5px; font-style: italic;}
</style>
We are adding google fonts. In order to add different fonts, please visit https://www.google.com/fonts
ng-app, ng-controller
<body ng-app=”angularJSHTTPCallModule” ng-controller=”angularJSHTTPCallController”>
Search form
<div>Stock Quote</div>
<div>
<form name=”stockQuoteForm”>
<input type=”text” required placeholder=”scriptcode” class=”form-control” ng-model=”scriptcode”>
<button ng-click=”getScriptDetails()” type=”button” class=”btn btn-primary”>Search</button>
</form>
</div>
By looking at above code two important attributes (directives) highlighted. More information about all available directives here
- ng-model- this directive will bind input value and make it available in the controller
- ng-click – it will trigger a function on click event
Search result
<table ng-show=”scriptDetails”>
<thead>
<tr>
<th>Name</th>
<th>symbol</th>
<th>LastTradePriceOnly</th>
<th>Ask</th>
<th>Bid</th>
<th>AverageDailyVolume</th>
<th>Currency</th>
<th>LastTradeDate</th>
<th>LastTradeTime</th>
<th>DaysLow</th>
<th>DaysHigh</th>
<th>YearLow</th>
<th>YearHigh</th>
<th>PE Ratio</th>
</tr>
</thead>
<tbody>
<tr>
<td>{{scriptDetails.query.results.quote.Name}}</td>
<td>{{scriptDetails.query.results.quote.symbol}}</td>
<td>{{scriptDetails.query.results.quote.LastTradePriceOnly}}</td>
<td>{{scriptDetails.query.results.quote.Ask}}</td>
<td>{{scriptDetails.query.results.quote.Bid}}</td>
<td>{{scriptDetails.query.results.quote.AverageDailyVolume}}</td>
<td>{{scriptDetails.query.results.quote.Currency}}</td>
<td>{{scriptDetails.query.results.quote.LastTradeDate}}</td>
<td>{{scriptDetails.query.results.quote.LastTradeTime}}</td>
<td>{{scriptDetails.query.results.quote.DaysLow}}</td>
<td>{{scriptDetails.query.results.quote.DaysHigh}}</td>
<td>{{scriptDetails.query.results.quote.YearLow}}</td>
<td>{{scriptDetails.query.results.quote.YearHigh}}</td>
<td>{{scriptDetails.query.results.quote.PERatio}}</td>
</tr>
</tbody>
</table>
JS
angularjsHttpCall.js
(function() {
var angularJSHTTPCallModule = angular.module(‘angularJSHTTPCallModule’,[]);
angularJSHTTPCallModule.controller(‘angularJSHTTPCallController’,function($scope,$http){
$scope.getScriptDetails=function(){
var url=’https://query.yahooapis.com/v1/public/yql’;
var query=’select%20*%20from%20yahoo.finance.quotes%20where%20symbol%20in%20(%22’+’\”+$scope.scriptcode+’%22)&format=json&diagnostics=true&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys&callback’;
url=url+’?q=’+query;
var response=$http.get(url);
response.success(function(data, status, headers, config) {
$scope.scriptDetails=data;
var js1=JSON.stringify(data);
console.log(“js12 “+js1);
});
response.error(function(data, status, headers, config) {
console.log(“failure “+data+” status “+status+” headers “+headers);
});
};
});
}());
in above code asynchronous successful response available from server is given to success method while error handled with error method.
Angular JS Controller
July 12, 2015 Leave a comment
Introduction
In earlier post we concentrated on the benefits of designing JS in a specific way. In this post we will look at
- How to configure Angular JS?
- Configure the controller
- Important angular JS specific attributes (directives)
- Important angular specific objects eg :- $scope, angular
Configure Angular JS
To work with the core angular js functionality one needs to include only angular js in view(jsp, html….)
<script src=”https://ajax.googleapis.com/ajax/libs/angularjs/1.3.15/angular.min.js”></script>
Configure Controller
Define Module in JS
In above case empty array indicates no dependency but has implicit dependency with core module.
Attach controller to the module
//Define MyController and attaching it to the module
myfirstAgnularModule.controller(‘MyController’,function($scope){
$scope.message=”Hello Angular”;
});
In above case $scope is an angular specific object. Any parameter which starts with $ managed by angular js.
In above case we are attaching message to $scope object. Anything which we are attaching to $scope object will be acting as models.
By looking at this example we can say controller is not directly communicate with a view (html) but it is through the model.
On macroscopic level controller is responsible for
- Organizing information
- Control things to visible/hide on view
- Communicate with remote server to fetch data.
Configure view for module and controller
<!– load angular js from CDN –>
<script src=”https://ajax.googleapis.com/ajax/libs/angularjs/1.3.15/angular.min.js”></script>
<body ng-app=”myfirstAgnularModule” ng-controller=”MyController”>
{{message}}
</body>
Angular js specific attributes/directives and binding expression
These attributes are known as directives
- ng-app
- Only one attribute must be present in whole html
- Whenever angular js find this attribute. It will bootstrap itself.
- ng-controller
- One page can have multiple ng-controller directives
- It must be defined at the same level or at child level of ng-app
- Binding expression
- In the above case {{message}} acts as binding expression
- Binding expression helps displaying model data to view.
Output
Complete Example
myFirstAngularExample.js
(function() {
var myfirstAgnularModule = angular.module(‘myfirstAgnularModule’,[]);
myfirstAgnularModule.controller(‘MyController’,function($scope){
$scope.message=”Hello Angular”;
});
}());
myFirstAngularExample.htm
<html>
<head>
<script src=”https://ajax.googleapis.com/ajax/libs/angularjs/1.3.15/angular.min.js”></script>
<script src=”myFirstAngularExample.js”></script>
</head>
<body ng-app=”myfirstAgnularModule” ng-controller=”MyController”>
{{message}}
</body>
</html>
Pre Angular JS
July 11, 2015 3 Comments
Target Audience: – Beginner
Angular JS is a Java script open source framework from Google and downloadable from https://angularjs.org/
Important concepts before start playing with Angular JS
Angular is based on following important concepts
- Using function expression instead of the function declaration
- Functions for encapsulation
- Using modules for functions
- Avoid using global variables
Function expressions VS function declaration
Function declaration
- As variable declaration starts with var function declaration starts with function.
- The JS object created same as a function name. In following case object with name myFunction created.
- Function declaration parsed and executed before any other expressions.
function myFunction(){
console.log (“I am in myFunction”);
}
Function expression
Assign function to variable.
By doing this, one can dynamically change call to the function.
Used inside function to make encapsulation and code more and more modular
var myWork=function(){
console.log(“myWork Invoked”);
};
Function expressions are of two types
An anonymous function expression
var myWork=function(){
console.log(“myWork Invoked”);
};
Named function expression
var myWork=function myWorkFunction(){
console.log(“myWork Invoked”);
};
Functions for encapsulation
function expression offer better facility for encapsulation
Consider the following simple example
//Step 1: – concentrate on implementation logic: -Function expression with global variable myProcess
var myProcess=function myProcessF(){
var preProcess=function(){
console.log(“in preProcess”);
};
var postProcess=function(){
console.log(“in postProcess”);
};
var doProcess=function(){
console.log(“in process”);
};
// Some private function which used internally
var somePrivateFunction=function(){
console.log(“some internal function”);
}
//Expose functions and variable which used outside this function: Good example of encapsulation
return{
//Aliasing
preProcessing:preProcess,
postProcessing:postProcess,
doProcessing:doProcess
};
};
//Invoke Function
var process =myProcess();
process.preProcessing();
process.doProcessing();
process.postProcessing();
When this code executed it give the following output.
Avoid creating Global variables
By looking at above example, we can see that myProcess is a global variable. These types of variables are candidate for overriding hence one needs to avoid creating global variables with the help of IIFY
(function() {
// The code here executed once in its own scope
}());
polganesh
GANESH POL 