To my understanding, JSON strings were ways to package information to be sent around, much like xml.
This is also what's highly circulated in the stack-exchange questions
eg: What is JSON and why would I use it?
However, a recent bot for a game that I play took json files as "scripts" of actions to perform. In this way, users of the bot were able to customize actions that the bot was expected to perform.
This seemed to violate my mental model of what json's were and what they could accomplish. My current suspicion is that rather than using these "script" json files as packages of information to send, they are instead processed internally by the bot, which then translates our "scripts" into real actions.
Please enlighten me if I've misunderstood what json is.
JSON is just a structure, literally it is "JavaScript Object Notation", http://json.org/.
processed internally by the bot
is basically what is going on.
The json string is parsed into an object, and based on the values of that object the bot reacts. There is no scripting involved in it. However, it is possible that some of the values are literally script in a string, which can be used in JavaScript with eval in order to execute.
I suspect that eval is not being used in that fashion though, and that the bot is simply reading key value pairs to take as instruction for example moveright:5 feet.
Here is a very quick example of taking expected commands in json and then executing them in some sort of process. The implementation is basic, just a proof of concept.
var json = '{ "actions": [ { "speak": "hello world" }, { "color" : "red" } ]}';
var obj = JSON.parse(json);
var i = 0;
var bot = document.querySelector("#bot");
var actions = {
speak : function(text){ bot.innerText = text; },
color : function(c){ bot.style.color = c; }
};
function act(action){
for(var key in action){
var value = action[key];
actions[key](value);
}
if(i <= obj.actions.length)
setTimeout(function(){
act(obj.actions[i++]);
},500);
}
setTimeout(function(){
act(obj.actions[i++]);
},500);
<div id="bot">:)</div>
Related
So let's say I've got a massive JSON file, and the general structure is roughly like so:
{
"apples": { complex object },
"oranges": { complex object },
"grapes": { complex object }
}
Is there some way to specifically target an object to return while using express? As in, say, if someone made a simple get request to my server, it'd return specifically the given object(s). I know the syntax and concept is completely wrong in this instance but for lack of a better way to say it, something like...
let testData = 'testdata.json';
app.get('/thing', res => {
res.json(testData.oranges);
}
I know you can return the entire file, but that adds a good amount of loading time in this instance, and is impractical in this particular case.
Or, alternatively - would it be better to have node parse the JSON file and split it into an apples.json, oranges.json, etc files to use? Trying to understand A, the best practice for doing something like this, and B, the most effective way to translate this into a practical application for a medium sized project.
Any thoughts or advice along this line - even if it's a library recommendation - would be greatly appreciated.
It should work if you make a POST request caring the payload of the specific 'thing', and then returning an object based on that thing. Example:
let testData = {
"apples": { complex object },
"oranges": { complex object },
"grapes": { complex object }
};
app.post('/route', (req, res) => {
thing = req.body.thing;
res.json(testData[thing]);
}
This is a GET request for some data and essentially since the JSON file can be used as a key/value store to query for the desired response data.
Assuming the query parameter for specifying the desired key for the object to return is part then the following example would work:
const testData = require('./testdata.json');
app.get('/thing', (req, res) => res.json(testdata[req.query.part]);
Querying for /thing?part=apples would return testdata.apples in the response.
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 have a rest service for which I am sending the Json data as ["1","2","3"](list of strings) which is working fine in firefox rest client plugin, but while sending the data in application the structure is {"0":"1","1":"2","2":"3"} format, and I am not able to pass the data, how to convert the {"0":"1","1":"2","2":"3"} to ["1","2","3"] so that I can send the data through application, any help would be greatly appreciated.
If the format of the json is { "index" : "value" }, is what I'm seeing in {"0":"1","1":"2","2":"3"}, then we can take advantage of that information and you can do this:
var myObj = {"0":"1","1":"2","2":"3"};
var convertToList = function(object) {
var i = 0;
var list = [];
while(object.hasOwnProperty(i)) { // check if value exists for index i
list.push(object[i]); // add value into list
i++; // increment index
}
return list;
};
var result = convertToList(myObj); // result: ["1", "2", "3"]
See fiddle: http://jsfiddle.net/amyamy86/NzudC/
Use a fake index to "iterate" through the list. Keep in mind that this won't work if there is a break in the indices, can't be this: {"0":"1","2":"3"}
You need to parse out the json back into a javascript object. There are parsing tools in the later iterations of dojo as one of the other contributors already pointed out, however most browsers support JSON.parse(), which is defined in ECMA-262 5th Edition (the specification that JS is based on). Its usage is:
var str = your_incoming_json_string,
// here is the line ...
obj = JSON.parse(string);
// DEBUG: pump it out to console to see what it looks like
a.forEach(function(entry) {
console.log(entry);
});
For the browsers that don't support JSON.parse() you can implement it using json2.js, but since you are actually using dojo, then dojo.fromJson() is your way to go. Dojo takes care of browser independence for you.
var str = your_incoming_json_string,
// here is the line ...
obj = dojo.fromJson(str);
// DEBUG: pump it out to console to see what it looks like
a.forEach(function(entry) {
console.log(entry);
});
If you're using an AMD version of Dojo then you will need to go back to the Dojo documentation and look at dojo/_base/json examples on the dojo.fromJson page.
I just working with JSON data and am playing around with jQuery and Ajax requests. Pretty basic stuff, but here's my problem.
I have a basic data set which I was using for time tracking. I know how to parse the simple JSON data like this:
{
"end" : "1/18/2011",
"start" : "1/18/2011",
"task" : "Code Review",
},
It's the more complicated stuff I'm trying to parse like this where I'm trying to pull the "time" data out.
{
"end" : "1/17/2011",
"start" : "1/17/2011",
"task" : "Exclusive Brands",
"time" : {
"analysis" : 4,
"documentation" : 3,
"meetings" : 2
}
This is the code for the script I've been using to parse the simple data:
$(function() {
$('.load').click(function(){
$.getJSON("data.js",function(data){
$.each(data.timesheet, function(i,data){
var div_data ="<div class='box'>"+data.start+" "+data.task+"</div>";
$(div_data).appendTo("#time-tracking");
});
}
);
return false;
});
});
My question is what's the format to parse the time data, or what's the best way to parse the information nested inside the time element?
Any help will be greatly appreciated.
A JSON string will be parsed into an object. When parsed, the time is the key of one object. You could retrieve the value of this object through the dot operator (.).
data = JSON.parse('{"end":"1/17/2011", "start":"1/17/2011", "task":"Exclusive Brands", "time": {"analysis":4, "documentation":3, "meetings":2 } }')
// => obj
data.time.analysis
// => 4
In your case similarly you could use the data.time.meetings to access your data from remote server.
Unless I am terribly mistaken, since jquery already converted data into a javascript for you, you should be able to access time as if it was a javascript object like so:
var analysis = data.time.analysis;
var documentation = data.time.documentation;
var meetings = data.time.meetings;
etc...