I have a mongoDB structure that looks like this:
values : { [
oneValue : {
number: '20'
unit: 'g'
}
differentValue : {
number : '30'
unit : 'g'
}
]}
I am using node js this is what I do:
doc.values.forEach(function(err, idx) {
var object = doc.values[idx];
}
And what ends up happening is I can get an object that looks like this:
object = oneValue : {
number: '20'
unit: 'g'
}
But node does not recognize it as a JSON because when I try to do JSON.parse(object) it doesn't know how to handle it.
I want to be able to get at the number field dynamically. So I don't want to say doc.values[idx].oneValue because this is a pretend case and in the real case oneValue could be one of 1000 different things. Does anyone know how I can access the 'number' field with this structure?
figured it out...
after
var object = docs.values[idx]
do this:
var objAsJson = JSON.stringify(object);
JSON.parse(objAsJson, function(k, v) {
console.log(k + " " + v);
});
That will print out all the data in the embedded object and you don't have to know the name.
Related
Introduction
I'm learning JavaScript on my own and JSON its something along the path. I'm working on a JavaScript WebScraper and I want, for now, load my results in JSON format.
I know I can use data base, server-client stuff, etc to work with data. But I want to take this approach as learning JSON and how to parse/create/format it's my main goal for today.
Explaining variables
As you may have guessed the data stored in the fore mentioned variables comes from an html file. So an example of the content in:
users[] -> "Egypt"
GDP[] -> "<td> $2,971</td>"
Regions[] -> "<td> Egypt </td>"
Align[] -> "<td> Eastern Bloc </td>"
Code
let countries = [];
for(let i = 0; i < users.length; i++)
{
countries.push( {
'country' : [{
'name' : users[i],
'GDP' : GDP[i],
'Region' : regions[i],
'Align' : align[i]
}]})
};
let obj_data = JSON.stringify(countries, null, 2);
fs.writeFileSync('countryballs.json', obj_data);
Code explanation
I have previously loaded into arrays (users, GDP, regionsm align) those store the data (String format) I had extracted from a website.
My idea was to then "dump" it into an object with which the stringify() function format would format it into JSON.
I have tested it without the loop (static data just for testing) and it works.
Type of error
let obj_data = JSON.stringify(countries, null, 2);
^
TypeError: Converting circular structure to JSON
--> starting at object with constructor 'Node'
| property 'children' -> object with constructor 'Array'
| index 0 -> object with constructor 'Node'
--- property 'parent' closes the circle
What I want from this question
I want to know what makes this JSON format "Circular" and how to make this code work for my goals.
Notes
I am working with Node.js and Visual Studio Code
EDIT
This is further explanation for those who were interested and thought it was not a good question.
Test code that works
let countries;
console.log(users.length)
for(let i = 0; i < users.length; i++)
{
countries = {
country : [
{
"name" : 'CountryTest'
}
]
}
};
let obj_data = JSON.stringify(countries, null, 2);
fs.writeFileSync('countryballs.json', obj_data);
});
Notice in comparison to the previous code, right now I am inputing "manually" the name of the country object.
This way absolutely works as you can see below:
Now, if I change 'CountryTest' to into a users[i] where I store country names (Forget about why countries are tagged users, it is out of the scope of this question)
It shows me the previous circular error.
A "Partial Solution" for this was to add +"" which, as I said, partially solved the problem as now there is not "Circular Error"
Example:
for(let i = 0; i < users.length; i++)
{
countries = {
country : [
{
"name" : users[i]+''
}
]
}
};
Resulting in:
Another bug, which I do not know why is that only shows 1 country when there are 32 in the array users[]
This makes me think that the answers provided are not correct so far.
Desired JSON format
{
"countries": {
"country": [
{
"name": "",
"GDP" : "",
"Region" : "",
"Align" : ""
},
{
"name": "",
"GDP" : "",
"Region" : "",
"Align" : ""
},
{
"name": "",
"GDP" : "",
"Region" : "",
"Align" : ""
}
]}
}
Circular structure error occurs when you have a property of the object which is the object itself directly (a -> a) or indirectly (a -> b -> a).
To avoid the error message, tell JSON.stringify what to do when it encounters a circular reference. For example, if you have a person pointing to another person ("parent"), which may (or may not) point to the original person, do the following:
JSON.stringify( that.person, function( key, value) {
if( key == 'parent') { return value.id;}
else {return value;}
})
The second parameter to stringify is a filter function. Here it simply converts the referred object to its ID, but you are free to do whatever you like to break the circular reference.
You can test the above code with the following:
function Person( params) {
this.id = params['id'];
this.name = params['name'];
this.father = null;
this.fingers = [];
// etc.
}
var me = new Person({ id: 1, name: 'Luke'});
var him = new Person( { id:2, name: 'Darth Vader'});
me.father = him;
JSON.stringify(me); // so far so good
him.father = me; // time travel assumed :-)
JSON.stringify(me); // "TypeError: Converting circular structure to JSON"
// But this should do the job:
JSON.stringify(me, function( key, value) {
if(key == 'father') {
return value.id;
} else {
return value;
};
})
The answer is from StackOverflow question,
Stringify (convert to JSON) a JavaScript object with circular reference
From your output, it looks as though users is a list of DOM nodes. Rather than referring to these directly (where there are all sort of possible cyclical structures), if you just want their text, instead of using users directly, try something like
country : [
{
"name" : users[i].textContent // maybe also followed by `.trim()
}
]
Or you could do this up front to your whole list:
const usersText = [...users].map(node => node.textContent)
and then use usersText in place of users as you build your object.
If GDP, regions and align are also references to your HTML, then you might have to do the same with them.
EUREKA!
As some of you have mentioned above, let me tell you it is not a problem of circularity, at first..., in the JSON design. It is an error of the data itself.
When I scraped the data it came in html format i.e <td>whatever</td>, I did not care about that as I could simply take it away later. I was way too focused in having the JSON well formatted and learning.
As #VLAZ and #Scott Sauyezt mentioned above, it could be that some of the data, if it is not well formatted into string, it might be referring to itself somehow as so I started to work on that.
Lets have a look at this assumption...
To extract the data I used the cheerio.js which gives you a kind of jquery thing to parse html.
To extract the name of the country I used:
nullTest = ($('table').eq(2).find('tr').eq(i).find('td').find('a').last());
//"Partial solution" for the OutOfIndex nulls
if (nullTest != null)
{
users.push(nullTest);
}
(nullTest helps me avoid nulls, I will implement some RegEx when everything works to polish the code a bit)
This "query" would output me something like:
whatEverIsInHereIfThereIsAny
or else.
to get rid off this html thing just add .html() at the end of the "jquery" such as:
($('table').eq(2).find('tr').eq(i).find('td').find('a').last().html());
That way you are now working with String and avoiding any error and thus solves this question.
I need a recursive function in javascript, which can return me all fieldname (Key Name) of my json document store in MarkLogic. JSON document is very dynamic and have multiple hierarchical elements. So need a function which can traverse through JSON and fetch all fieldname (Keys Name).
One option I thought was to get entire document into MaP object and run Map function to get all keys. But not sure whether MarkLogic allows to capture entire json doucment into Map and one can read fields names.
Thanks in Advance
Got the function to iterate through JSON document to pull Key Name
Sample JSON
var object = {
aProperty: {
aSetting1: 1,
aSetting2: 2,
aSetting3: 3,
aSetting4: 4,
aSetting5: 5
},
bProperty: {
bSetting1: {
bPropertySubSetting : true
},
bSetting2: "bString"
},
cProperty: {
cSetting: "cString"
}
}
Solution available at StackOverflow
Recursively looping through an object to build a property list
*
function iterate(obj, stack) {
for (var property in obj) {
if (obj.hasOwnProperty(property)) {
if (typeof obj[property] == "object") {
iterate(obj[property], stack + '.' + property);
} else {
console.log(property + " " + obj[property]);
$('#output').append($("<div/>").text(stack + '.' + property))
}
}
}
}
iterate(object, '')*
This handy page may help: MarkLogic - Native JSON
The following will extract all property names
var json = fn.head(xdmp.unquote('{ foo : "bar", baz : { buz: "boo", chicken : { option1 : "soup", option2 : "salad" } } }'))
json.xpath("//*/name()");
Output: foo baz buz chicken option1 option2
If, after reviewing the samples on that page you still need assistance, I suggest updating your question with example JSON and desired output (even if it is meant to be dynamic, an example people can copy/paste and work with helps alot)
I'm trying to increase different values in my collection using the same code.
I'm trying to compute that in a function where the updated properties will depend on the parameters:
BuyEntitee : function(id_fb,entitee)
{
var j = Joueur.findOne({id_fb:id_fb});
var prix_current = j["prix_"+entitee];
var update_query = {};
update_query[entitee+"s"] = j[entitee+"s"] + 1;
update_query["prix_"+entitee] = Math.round(50*Math.pow(1.1,j[entitee+"s"]));
Joueur.update( {id_fb:id_fb}, {
$set: {update_query}
}
);
j = Joueur.findOne({id_fb:id_fb}); // on recharge le jouer ... utile ??
console.log('nbHumains : ' + j.humains+ ' query = '+JSON.stringify(update_query));
return j.rochers;
}
But unfortunately, the query is 1 level too deep in the structure :
meteor:PRIMARY> db.joueur.findOne()
{
"_id" :
"humains" : 12,
"prix_humain" : 50,
"update_query" :
{
"humains" : 13,
"prix_humain" : 157
}
}
I'm creating the update_query object so that I can programmatically change the parameters in the update function (saw this here).
Is there a way to perform that?
What happened is, in fact, a result of the ES6 syntactic sugar for specifying objects.
When you specified {update_query}, it was interpreted as an object with the key of "update_query" and the value of the variable update_query.
Therefore, it is the equivalent of:
Joueur.update( {id_fb:id_fb}, {
$set: {
update_query: update_query
}
}
);
What you really want is to assign the update_query itself to the $set key:
Joueur.update( {id_fb:id_fb}, {
$set: update_query
}
);
On a side note, you probably want to use the $inc modifier in order to increment the entitee+"s" by 1.
I have the following code in a display template in sharepoint, I have an array of objects and I need to have the following result.
Name1
Name2
Name3
So I can replace the default rendering of sharepoint multiple people user field with a tooltip.
However, I dont know how to iterate and then concatenate:
Screenshot:
Code:
// List View - Substring Long String Sample
// Muawiyah Shannak , #MuShannak
(function () {
// Create object that have the context information about the field that we want to change it's output render
var projectTeamContext = {};
projectTeamContext.Templates = {};
projectTeamContext.Templates.Fields = {
// Apply the new rendering for Body field on list view
"Project_x0020_Team": { "View": ProjectTeamTemplate }
};
SPClientTemplates.TemplateManager.RegisterTemplateOverrides(projectTeamContext);
})();
// This function provides the rendering logic
function ProjectTeamTemplate(ctx) {
var projectTeamValue = ctx.CurrentItem[ctx.CurrentFieldSchema.Name];
//newBodyvalue should have the list of all display names and it will be rendered as a tooltip automaticlaly
return "<span title='" + projectTeamValue + "'>" + newBodyValue + "</span>";
}
You can "map" property values from the projectTeamValue array objects into a new array, then "join" those values together (using ", " as the separator in this example) all in one go:
var newBodyValue = projectTeamValue.map(function(person) {
return person.value;
}).join(", ");
If your projectTeamValue array looked like:
[{ value: "Name1" }, { value: "Name2" }, { value: "Name3" }]
Then newBodyValue would be:
"Name1, Name2, Name3"
jsFiddle Demo
Side note: Array.prototype.map() was not available in IE 8 and below but should work in every other browser.
I am sending some request on a server and it's reply me this:
{"COLUMNS":["REGISTRATION_DT","USERNAME","PASSWORD","FNAME","LNAME","EMAIL","MOBILE","FACEBOOK_ID"],"DATA":[["March, 17 2012 16:18:00","someuser",somepass,"somename","somesur","someemail",sometel,"someid"]]}
I tried a lot but nothing seems to working for me!
var xml2 = this.responseData;
var xml3 = xml2.getElementsByTagName("data");
Ti.API.log(xml3.FNAME);
For this code I get "null".
Any help would be appreciated!
If you're trying to use JSON format, your problem is that the data within the [...] also needs to be in pairs, and grouped in {...} like here.
For instance,
{
"sales": [
{ "firstname" : "John", "lastname" : "Brown" },
{ "firstname" : "Marc", "lastname" : "Johnson" }
] // end of sales array
}
So you might have:
{"COLUMNS": [
{"REGISTRATION_DT" : "19901212", "USERNAME" : "kudos", "PASSWORD" : "tx91!#1", ... },
{"REGISTRATION_DT" : "19940709", "USERNAME" : "jenny", "PASSWORD" : "fxuf#2", ... },
{"REGISTRATION_DT" : "20070110", "USERNAME" : "benji12", "PASSWORD" : "rabbit19", ... }
]
}
If the server is sending you something which you refer to as res, you can just do this to parse it in your Javascript:
var o=JSON.parse(res);
You can then cycle through each instance within columns like follows:
for (var i=0;i<o.COLUMNS.length;i++)
{
var date = o.COLUMNS[i].REGISTRATION_DT; ....
}
see that link. READ JSON RESPONSE
It's perfect.
JSON objects work just like any normal javascript objects or dictionaries
// You can do it this way
var data = this.responseData["DATA"]
// Or this way
var data = this.responseData.DATA
In your case, COLUMNS and data are both arrays, so it looks like you're trying to get the element from data that corresponds to the "FNAME" element in COLUMNS?
var columns = this.responseData["COLUMNS"];
var data = this.responseData["DATA"][0];
for(var i=0; i<columns.length; i++){
if(columns[i] == "FNAME"){
Ti.API.log(data[i]);
}
}
EDIT: If you can't change the data on the server end, you can make your own object client side. This also helps if you have to refer to multiple columns (which you probably do).
var columns = this.responseData["COLUMNS"];
var data = this.responseData["DATA"][0];
var realData = {};
for(var i=0; i<columns.length; i++){
realData[columns[i]] = data[i];
}
// Now you can access properties directly by name.
Ti.API.log(data.FNAME);
More edit:
My answers only consider the first row in DATA, because I misread originally. I'll leave it up to you to figure out how to process the others.
If you got here trying to find out how to read from [Response object] (as I did) -
this what can help:
- if you use fetch don't forget about res.json() before logging in console
fetch(`http://localhost:3000/data/${hour}`, {
method: 'get'
})
.then(res => {
return res.json()
})
.then((response) => {
console.log('res: ' + JSON.stringify(response))
})
Testing out your code in http://jsonlint.com/, it says that your server's response is not a valid JSON string.
Additionally, I recommend checking out jQuery.parseJSON http://api.jquery.com/jQuery.parseJSON/
Just use JSON.parse(serverResponse)