JavaScript, Web API import with D3 (Data Driven Document) - json

I'd like to import data from an Web API (JSON format) and use it for visualization. As you see in the following code, I've already implemented everything and it works (almost).
Question: The dataExport isn't the same as data. Why? How can I change my code so that dataExport the same like data?
Code:
var dataExport = d3.json("http://link to the Server...", function(error, data){
if(error) {
console.log(error);
} else {
console.log(data);
console.log(data.collection.items);
}
});
console.log(dataExport);
Console.log(data);
Object {collection: Object}
collection: Object
href: "http://link to the Server..."
items: Array[50]
links: Array[1]
queries: Array[1]
version: "1.0"
__proto__: Object
__proto__: Object
Console.log(dataExport);
Object {header: function, mimeType: function, responseType: function, response: function, get: function…}
abort: function (){return c.abort(),i}
get: function (){return i.send.apply(i,[n].concat(Qo(arguments)))}
header: function (n,t){return n=(n+"").toLowerCase(),arguments.length<2?a[n]:(null==t?delete a[n]:a[n]=t+"",i)}
mimeType: function (n){return arguments.length?(t=null==n?null:n+"",i):t}
on: function (){var r=e.apply(t,arguments);return r===t?n:r}
post: function (){return i.send.apply(i,[n].concat(Qo(arguments)))}
response: function (n){return e=n,i}
responseType: function (n){return arguments.length?(s=n,i):s}
send: function (e,r,u){if(2===arguments.length&&"function"==typeof r&&(u=r,r=null),c.open(e,n,!0),null==t||"accept"in a||(a.accept=t+",*/*"),c.setRequestHeader)for(var l in a)c.setRequestHeader(l,a[l]);return null!=t&&c.overrideMimeType&&c.overrideMimeType(t),null!=s&&(c.responseType=s),null!=u&&i.on("error",u).on("load",function(n){u(null,n)}),o.beforesend.call(i,c),c.send(null==r?null:r),i}
__proto__: Object
Thanks!

because you store the whole parsing-process in your dataStore-variable, while the data-variable only contains the data you call within the d3.json - as it should be.
you don't need to use another variable, so just try
d3.json("http://link to the Server...", function(error, dataStore){
if(error) {
console.log(error);
} else {
console.log(dataStore);
console.log(dataStore.collection.items);
}
});
dataStore should contain the wanted results
edit: to access it outside the d3.json
var dataStore; //declare a global variable somewhere at the beginning of your script
and then
d3.json("http://link to the Server...", function(error, data){
if(error) {
console.log(error);
} else {
dataStore=data;
}
});
console.log(dataStore);
console.log(dataStore.collection.items);

Related

Post JSON in DynamoDB via Lambda

I have trouble storing a JSON file in my DynamoDB table with the help of my Lambda function and my API Gateway on AWS. I have the following piece of code which gets executed once I press a button on my HTML site:
$('#submit').on('click', function(){
var example = {"number":"121212"};
$.ajax({
type: 'POST',
url: API_URL,
data: JSON.stringify(example),
contentType: "application/json",
success: function(data){
location.reload();
}
});
return false;
});
When pressed the website reloads, hence I assume function has successfully executed. However my problem is that the data does not arrive in the correct format in the lambda function and hence does not execute properly. When checking in CloudWatch it is shown as { number: '121212' } instead of {"number":"121212"}. Any idea how I can make sure that the value 'arrives' has a valid JSON format in my Lambda function?
Here's my Lambda function:
exports.handler = function index(e, ctx, callback) {
var params = {
Item: { number: e.number },
TableName: 'collectionOfNumbers'
};
docCLient.put(params, function(err, data) {
if (err) {
callback(err, null);
} else {
callback(null, data);
}
});
}
If I'm reading this right, e.number is the value of the JSON parameter 'number' that you are passing in, e.g. '121212'. I'm making the assumption from the usage that docClient is putItem under the hood.
I think your Item param should look like:
Item: {"number": {N: e.number}}
See AWS Docs for info regarding PutItem https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_PutItem.html

Wrong data format for store loadData method ExtJS

I want to call JSON data as much as the amount of data in the store. Here is the code:
storeASF.each(function(stores) {
var trano = stores.data['arf_no'];
Ext.Ajax.request({
results: 0,
url: '/default/home/getdataforeditasf/data2/'+trano+'/id/'+id,
method:'POST',
success: function(result, request){
var returnData = Ext.util.JSON.decode(result.responseText);
arraydata.push(returnData);
Ext.getCmp('save-list').enable();
Ext.getCmp('cancel-list').enable();
},
failure:function( action){
if(action.failureType == 'server'){
obj = Ext.util.JSON.decode(action.response.responseText);
Ext.Msg.alert('Error!', obj.errors.reason);
}else{
Ext.Msg.alert('Warning!', 'Server is unreachable : ' + action.response.responseText);
}
}
});
id++;
});
storeARF.loadData(arraydata);
StoreASF contains data[arf_no] which will be used as a parameter in Ajax request url. StoreASF could contain more than one set of the object store, so looping is possible. For every called JSON data from request would be put to array data, and after the looping is complete, I save it to storeARF with the loadData method.
The problem is, my data format is wrong since loadData can only read JSON type data. I already try JSON stringify and parse, but couldn't replicate the data format. Any suggestion how to do this? Thank you.
Rather than using Ext.util.Json.decode(), normalize the data in success() method using your own logic. For example:
success: function (response) {
console.log(response);
var myData = [];
Ext.Array.forEach(response.data, function (item) {
myData.push({
name: item.name,
email: item.email,
phone: item.phone
});
});
store.load();
}

AJAX HTTP-POST-Request - Saving JSON responses

I want to make a HTTP-POST-Request with AJAX to call a JSON API. So, the API should return a response in JSON. I can see on the console of the API, that the request is successful. But the problem is, that no data or status is returned, or that I can't use it with JQuery. Here is my function:
$.post("http://api-adress/controller",
{
email: input_mail,
password: input_pw
},
function(data, status){
alert(data);
alert(status);
}, 'json');
I guess the problem is that the response from the Server does not get saved in the variables data and status correctly.
I would suggest to change a little bit your code like below:
var dataString = {
email: input_mail,
password: input_pw
}
$.post("http://api-adress/controller", dataString, function (result) {
})
.done(function (result) {
//Here is your result. You must parseJSON if it is json format
var data = jQuery.parseJSON(result);
})
.fail(function () {
//use this if you need it
})
Also make sure that you get the response through firebug in console tab. You can check there what you post, what you get etc.

How to dynamically read external json files in node.js?

I am creating a website that reads externally hosted json files and then uses node.js to populate the sites content.
Just to demonstrate what I'm after, this is a really simplified version of what I'm trying to do in node.js
var ids = [111, 222, 333];
ids.forEach(function(id){
var json = getJSONsomehow('http://www.website.com/'+id+'.json');
buildPageContent(json);
});
Is what I want to do possible?
(Marked as a duplicate of "How do I return the response from an asynchronous call?" see my comment below for my rebuttal)
You are trying to get it synchronously. What you should aim for instead, is not a function used like this:
var json = getJSONsomehow('http://www.website.com/'+id+'.json');
but more like this:
getJSONsomehow('http://www.website.com/'+id+'.json', function (err, json) {
if (err) {
// error
} else {
// your json can be used here
}
});
or like this:
getJSONsomehow('http://www.website.com/'+id+'.json')
.then(function (json) {
// you can use your json here
})
.catch(function (err) {
// error
});
You can use the request module to get your data with something like this:
var request = require('request');
var url = 'http://www.website.com/'+id+'.json';
request.get({url: url, json: true}, (err, res, data) => {
if (err) {
// handle error
} else if (res.statusCode === 200) {
// you can use data here - already parsed as json
} else {
// response other than 200 OK
}
});
For a working example see this answer.
For more info see: https://www.npmjs.com/package/request
I think problem is in async request. Function will return result before request finished.
AJAX_req.open( "GET", url, true );
Third parameter specified async request.
You should add handler and do all you want after request finished.
For example:
function AJAX_JSON_Req( url ) {
var AJAX_req = new XMLHttpRequest.XMLHttpRequest();
AJAX_req.open( "GET", url, true );
AJAX_req.setRequestHeader("Content-type", "application/json");
AJAX_req.onreadystatechange = function() {
if (AJAX_req.readyState == 4 && AJAX_req.status == 200) {
console.log(AJAX_req.responseText);
}
};
}

Calling a JSON function from a module in Dojo

The contents of my dataHelper.js file:
define(["dojo/_base/declare", "dojo/dom", "dojo/_base/xhr", "dojo/json"],
function(declare, dom, xhr, json){
return {
getJSON: function(){
xhr.get({
url: "../../cpuusage.json",
handleAs: "json",
load: function(jsonData){
return jsonData;
},
error: function() {
}
});
}
};
});
I'm trying to run this from my index.html as follows:
var chartData = dataHelper.getJSON();
I think I have several issues. First of all, I'm not sure my module and the getJSON function is defined correctly. Secondly I get errors on my console:
TypeError: this.source is undefined
[Break On This Error]
= [],
dojo.js (line 362)
SyntaxError: missing : after property id
},
dojo.js (line 330)
SyntaxError: missing : after property id
},
dojo.js (line 330)
SyntaxError: missing : after property id
},
All I want to achieve first is load the json data into the chartData variable. Many thanks.
The first issue I'm seeing is you are treating an asynchronous process as if it was a synchronous one. The xhr.get returns immediately after the request to the server is sent, it does not block until a response is received.
First, I would add a console.log to your module definition to ensure that your dataHelper module is being loaded correctly.
define(["dojo/_base/xhr"],
function(xhr){
console.log('dataHelper.js loaded');
return {
//
};
});
Also note that above you aren't using any of the base dojo modules except dojo/_base/xhr, so it is unnecessary to include them (unless they are used outside this snippet).
You need to update your code to handle this call asynchronously. To do this, you could take advantage of the fact that the xhr.get method returns a Deferred object. This class makes dealing with asynchronous in a consistent manner quite easy.
To do this, update the dataHelper module to return the result of the xhr call:
define(["dojo/_base/xhr"], function(xhr){
return {
getJSON: function(){
//this returns a Deferred object, what to do on load and error is then handled by the invoker
return xhr.get({
url: "../../cpuusage.json",
handleAs: "json"
});
}
};
});
Then, when utilizing this module:
//replace dataHelper with whatever it's path is
require(['dataHelper'],function(dataHelper){
var deferred = dataHelper.getJSON();
deferred.then(function(data){
//this function is invoked once the data has been fully loaded
}, function(error){
//this function is invoked if an error occurs while loading the data (in case of a server error response or if the response isn't in the format you specified)
});
});
This is my proposal:
Your dataHelper.js file:
define("dataHelper", ["dojo/_base/declare", "dojo/dom", "dojo/_base/xhr"],
function(declare, dom, xhr){
return declare("dataHelper", [], {
getJSON: function(){
return xhr.get({
url: "../../cpuusage.json",
handleAs: "json"
});
});
};
});
your invocation:
require(["dataHelper"], function(dataHelper) {
var chartData;
dataHelper.getJSON().then(function(jsonData) {
chartData = jsonData;
//Continue doing stuff with chartData in here, not outside
});
});