I would like to extend the native JSON object of node.js. In my example, I was able to extend it to add a merge(json1, json2) function, which merges 2 JSONs:
JSON.merge = function(target) {
var sources = [].slice.call(arguments, 1);
sources.forEach(function (source) {
for (var prop in source) {
target[prop] = source[prop];
}
});
return target;
}
This script is larglely inspired from this question: Combine or merge JSON on node.js without jQuery
To have a cleaner code, I put this script in a library folder, and require it in my main script. This is what I did...
My lib/JSON.js file:
extends.merge = function(target){
// The same script as above.
}
and in my app.js file:
JSON = require('./lib/JSON')
It works well, but now, native JSON methods don't work (like .stringify). Then I digged a little bit, and tried to extend JSON using .prototype, like this (in lib/JSON.js):
extends.prototype.merge = ...
But get the following error:
TypeError: Cannot set property 'merge' of undefined
I really don't know what to do (and what I'm doing) since solving a problems causes another problem.
Please, need help.
Thanks.
Related
I am creating functional tests dynamically using Intern v4 and dojo 1.7. To accomplish this I am assigning registerSuite to a variable and attaching each test to the Tests property in registerSuite:
var registerSuite = intern.getInterface('object').registerSuite;
var assert = intern.getPlugin('chai').assert;
// ...........a bunch more code .........
registerSuite.tests['test_name'] = function() {
// READ JSON FILE HERE
var JSON = 'filename.json';
// ....... a bunch more code ........
}
That part is working great. The challenge I am having is that I need to read information from a different JSON file for each test I am dynamically creating. I cannot seem to find a way to read a JSON file while the dojo javascript is running (I want to call it in the registerSuite.tests function where it says // READ JSON FILE HERE). I have tried dojo's xhr.get, node's fs, intern's this.remote.get, nothing seems to work.
I can get a static JSON file with define(['dojo/text!./generated_tests.json']) but this does not help me because there are an unknown number of JSON files with unknown filenames, so I don't have the information I would need to call them in the declare block.
Please let me know if my description is unclear. Any help would be greatly appreciated!
Since you're creating functional tests, they'll always run in Node, so you have access to the Node environment. That means you could do something like:
var registerSuite = intern.getPlugin('interface.object').registerSuite;
var assert = intern.getPlugin('chai').assert;
var tests = {};
tests['test_name'] = function () {
var JSON = require('filename.json');
// or require.nodeRequire('filename.json')
// or JSON.parse(require('fs').readFileSync('filename.json', {
// encoding: 'utf8'
// }))
}
registerSuite('my suite', tests);
Another thing to keep in mind is assigning values to registerSuite.tests won't (or shouldn't) actually do anything. You'll need to call registerSuite, passing it your suite name and tests object, to actually register tests.
I have a problem with my application. Anyone can help me?
Error:
Converting circular structure to JSON
My Service to create items and save on localstorage:
addItem(item: Item): void {
this.itens.unshift(item);
let itens;
if (localStorage.getItem('itens') == null){
itens = [];
itens.unshift(itens);
localStorage.setItem('itens', JSON.stringify(itens));
} else {
JSON.parse(localStorage.getItem('itens'));
itens.unshift(itens);
localStorage.setItem('itens', JSON.stringify(itens));
}
}
And my component.ts:
addItem(): void {
this.itemAdicionado.emit({
nome: this.nome,
unidade: this.unidade,
quantidade: this.quantidade,
preco: this.preco,
perecivel: true,
validade: this.validade,
fabricacao: this.fabricacao,
});
this.nome = '';
this.unidade ;
this.quantidade ;
this.preco;
this.validade;
this.fabricacao;
console.log(this.nome, this.unidade, this.quantidade, this.preco, this.validade, this.fabricacao);
}
This isn't an Angular error. It's a JavaScript runtime error thrown by the JSON.stringify function. The error tells you that itens contains a circular object reference. This is OK while you run the application, but when stringifying it causes a problem: the JSON generated would become infinitely long.
As Kevin Koelzer indicated in his answer. The problem is that you wrote itens.unshift(itens);. Basically this adds the array of items to the array of items, thus creating a circular reference. Therefore, writing itens.unshift(item); instead solves your problem and is probably what you intended to do anyway.
itens.unshift(itens);
could this be:
itens.unshift(iten);
I'm starting to write Google scripts to automatize certain tasks, and here I'm stuck on a problem I can't figure out by myself. I must say I'm neither an expert in app scripts (yet) nor in javascript.
Here is my problem. I make a call to a (private) REST API to retrieve some data. I get the result, parse it to get a Json object. Then I want to write some properties in a spreadsheet. For some reason, I can't get to manipulate nested objects.
Say I have a list of this json payload :
{
id: 2146904633,
status: "in_progress",
success_probability: 99,
amount: "0.0",
decision_maker: "Bob Mauranne",
business_contact: {
id: 2142664162,
nickname: "NIL",
}
}
EDIT : I made a mistake with the code I pasted (businessContact was not declared, instead a variable bc was declared).Thanks for the comment :) The code below is correct now, but still doesn't work.
I get it like with this (overly simplified) code :
var response = UrlFetchApp.fetch(url);
var dataAll = JSON.parse(response.getContentText());
var data, businessContact;
for (i = 0; i < dataAll.length; i++) {
data = dataAll[i];
businessContact = data.business_contact;
Logger.log(data.status);
Logger.log(businessContact);
Logger.log(businessContact.id);
}
My problem is that when I call businessContact.id I get the error "TypeError: unable to read property id from null object". And I don't understand since I can see the content from businessContact : either from the log call or from the debugger, it's definately not null.
It seems to happen only on nested objects, because on simple properties, I don't have any error. And I have the same problems on all nested objects, whatever json payload I've tried so far...
I searched on the internet for a solution but found none. It probably is very basic, but I can't get it to work.
Any idea ?
You never define "businessContact" that your using in the logger. You define "bc" but not "businessContact". If you changed it to Logger.log(bc.id) it should work.
Here is a trimmed down version of what your trying to do also.
function getJSON() {
var url = "your url";
var response = UrlFetchApp.fetch(url).getContentText();
var data = JSON.parse(response)
data.forEach(function(item) {
Logger.log(item.business_contact.id)
})
}
Heres an example pulling weather data.
function myFunction() {
var url = "https://www.aviationweather.gov/gis/scripts/TafJSON.php";
var response = UrlFetchApp.fetch(url).getContentText();
var data = JSON.parse(response)
data.features.forEach(function(feature) {
Logger.log(feature.properties.id)
})
}
I finally found the solution. This code is in a loop, sometimes the object business_contact is null and I hadn't seen it :|
Clearly I should stop working late in the evening when I learn a new technology ...
My bad, sorry for the noise, and thanks for the answers and comments guys.
This is a slightly messy questions. Although it appears I'm asking question about amCharts, I really just trying to figure how to extract an array from HTTP request and then turn it into a variable and place it in to 3-party javacript.
It all starts here, with this question, which was kindly answered by AmCharts support.
As one can see from the plnker. The chart is working. Data for the chart is hard coded:
`var chartData = [{date: new Date(2015,2,31,0,0,0, 0),value:372.10,volume:2506100},{date: new Date(2015,3,1,0, 0, 0, 0),value:370.26,volume:2458100},{date: new Date(2015,3,2,0, 0, 0, 0),value:372.25,volume:1875300},{date: new Date(2015,3,6,0, 0, 0, 0),value:377.04,volume:3050700}];`
So we know the amCharts part works. Know where the problem is changing hard coded data to a json request so it can be dynamic. I don't think this should be tremendously difficult, but for the life of me I can't seem figure it out.
The first issue is I can't find any documentation on .map, .subscribe, or .observable.
So here is a plunker that looks very similar to the first one, however it has an http providers and injectable. It's broken, because I can't figure out how to pull the data from the service an place it into the AmCharts function. I know how pull data from a http provider and display it in template using NgFor, but I don't need it in the template (view). As you can see, I'm successful in transferring the data from the service, with the getTitle() function.
this.chart_data =_dataService.getEntries();
console.log('Does this work? '+this.chart_data);
this.title = _dataService.getTitle();
console.log('This works '+this.title);
// Transfer the http request to chartData to it can go into Amcharts
// I think this should be string?
var chartData = this.chart_data;
So the ultimate question is why can't I use a service to get data, turn that data into a variable and place it into a chart. I suspect a few clues might be in options.json as the json might not be formatted correctly? Am I declaring the correct variables? Finally, it might have something to do with observable / map?
You have a few things here. First this is a class, keep it that way. By that I mean to move the functions you have inside your constructor out of it and make them methods of your class.
Second, you have this piece of code
this.chart_data =_dataService.getEntries().subscribe((data) => {
this.chart_data = data;
});
What happens inside subscribe runs asynchronously therefore this.chart_data won't exist out of it. What you're doing here is assigning the object itself, in this case what subscribe returns, not the http response. So you can simply put your library initialization inside of the subscribe and that'll work.
_dataService.getEntries().subscribe((data) => {
if (AmCharts.isReady) {
this.createStockChart(data);
} else {
AmCharts.ready(() => this.createStockChart(data));
}
});
Now, finally you have an interesting thing. In your JSON you have your date properties contain a string with new Date inside, that's nothing but a string and your library requires (for what I tested) a Date object, so you need to parse it. The problem here is that you can't parse nor stringify by default a Date object. We need to convert that string to a Date object.
Look at this snippet code, I used eval (PLEASE DON'T DO IT YOURSELF, IS JUST FOR SHOWING PURPOSES!)
let chartData = [];
for(let i = 0; i < data[0].chart_data.length; i++) {
chartData.push({
// FOR SHOWING PURPOSES ONLY, DON'T TRY IT AT HOME
// This will parse the string to an actual Date object
date : eval(data[0].chart_data[i].date);
value : data[0].chart_data[i].value;
volume : data[0].chart_data[i].volume;
});
}
Here what I'm doing is reconstructing the array so the values are as required.
For the latter case you'll have to construct your json using (new Date('YOUR DATE')).toJSON() and you can parse it to a Date object using new Date(yourJSON) (referece Date.prototype.toJSON() - MDN). This is something you should resolve in your server side. Assuming you already solved that, your code should look as follows
// The date property in your json file should be stringified using new Date(...).toJSON()
date : new Date(data[0].chart_data[i].date);
Here's a plnkr with the evil eval. Remember, you have to send the date as a JSON from the server to your client and in your client you have to parse it to a Date.
I hope this helps you a little bit.
If the getEntries method of DataService returns an observable, you need to subscribe on it to get data:
_dataService.getEntries().subscribe(
(data) => {
this.chart_data = data;
});
Don't forget that data are received asynchronously from an HTTP call. The http.get method returns an observable (something "similar" to promise) will receive the data in the future. But when the getEntries method returns the data aren't there yet...
The getTitle is a synchronous method so you can call it the way you did.
I am new to Angular and I am trying to build a simple todo application using it. I have designed a module called TodoServices in which I am creating a User service using the factory method. The code looks something like:
angular.module('TodoServices', ["ngResource"])
.factory('User', function($resource){
return $resource('http://todoapi.rohanchhabra.in/users/:id');
});
The code in my app.js looks like:
var angularApp = angular.module('angularApp', ['TodoServices']);
angularApp.controller('UsersController', function(User){
this.users = {};
this.users = User.query();
});
When I run my application, I get this error: Error link
I think this is because my web service is returning an object which not only has the data but also has a few other things such as a status and messages. Now Is it a wrong way of doing it? Should I just return the array from the back end? What is the actual problem here and how to solve this?
As your error link says:
By default, all resource actions expect objects, except query which expects arrays.
You should use an other function like User.Get() when you're not expecting an array but just a single object.