Develop Reference

How do I join separate json objects output from a for loop into an array?

I am scraping websites using CasperJS and one of the tasks involve crawling across url set by a for loop counter. The url looks like this
www.example.com/page/no=
where the no is any number from 0-10 set by the for loop counter. The scraper then goes through all the pages, scrapes the data into a JSON object and repeats until no=10.
The data that I am trying to get is stored in discrete groups in each page- what I would like to work with is a single JSON object by joining all the scraped output from each page.
Imagine Page1 has Expense 1 and the object I am getting is { expense1 } and Page 2 has Expense 2 and object that I am getting is { expense2 }. What I would like to have is one JSON at the end of scraping that looks like this:
scrapedData = {
"expense1": expense1,
"expense2": expense2,
}
What I am having trouble is joining all the JSON object into one array.
I initialized an empty array and then each object gets pushed to array.
I have tried a check where if iterator i in for loop is equal to 10, then the JSON object is printed out but that didnt seem to work. I looked up and it seems Object spread is an option but I am not sure how to use it this case.
Any pointers would be helpful. Should I be using any of the array functions like map?
casper.then(function(){
var url = "https:example.net/secure/SaFinShow?url=";
//We create a for loop to go open the urls
for (i=0; i<11; i++){
this.thenOpen(url+ i, function(response){
expense_amount = this.fetchText("td[headers='amount']");
Date = this.fetchText("td[headers='Date']");
Location = this.fetchText("td[headers='zipcode']");
id = this.fetchText("td[headers='id']");
singleExpense = {
"Expense_Amount": expense_amount,
"Date": Date,
"Location": Location,
"id": id
};
if (i ===10){
expenseArray.push(JSON.stringify(singleExpense, null, 2))
this.echo(expenseArray);
}
});
};
});

Taking your example and expanding on it, you should be able to do something like:
// Initialize empty object to hold all of the expenses
var scrapedData = {};
casper.then(function(){
var url = "https:example.net/secure/SaFinShow?url=";
//We create a for loop to go open the urls
for (i=0; i<11; i++){
this.thenOpen(url+ i, function(response){
expense_amount = this.fetchText("td[headers='amount']");
Date = this.fetchText("td[headers='Date']");
Location = this.fetchText("td[headers='zipcode']");
id = this.fetchText("td[headers='id']");
singleExpense = {
"Expense_Amount": expense_amount,
"Date": Date,
"Location": Location,
"id": id
};
// As we loop over each of the expenses add them to the object containing all of them
scrapedData['expense'+i] = singleExpense;
});
};
});
After this runs the scrapedData variable should be of the form:
scrapedData = {
"expense1": expense1,
"expense2": expense2
}
Updated code
One problem with the above code is that inside the for loop when you loop over the expenses, the variables should be local. The variable names also should not be Date and Location since those are built-in names in JavaScript.
// Initialize empty object to hold all of the expenses
var scrapedData = {};
casper.then(function(){
var url = "https:example.net/secure/SaFinShow?url=";
//We create a for loop to go open the urls
for (i=0; i<11; i++){
this.thenOpen(url+ i, function(response){
// Create our local variables to store data for this particular
// expense data
var expense_amount = this.fetchText("td[headers='amount']");
// Don't use `Date` it is a JS built-in name
var date = this.fetchText("td[headers='Date']");
// Don't use `Location` it is a JS built-in name
var location = this.fetchText("td[headers='zipcode']");
var id = this.fetchText("td[headers='id']");
singleExpense = {
"Expense_Amount": expense_amount,
"Date": date,
"Location": location,
"id": id
};
// As we loop over each of the expenses add them to the object containing all of them
scrapedData['expense'+i] = singleExpense;
});
};
});

how can i convert my data in javascript server side to json object and array?

i'm working with xpages and javascript server side i want to convert the fields in format json then i parse this dat and i put them in a grid,the problem is that these fields can contains values :one item or a list how can i convert them in json ?
this is my code :
this.getWFLog = function ()
{
var wfLoglines = [];
var line = "";
if (this.doc.hasItem (WF.LogActivityPS) == false) then
return ("");
var WFLogActivityPS = this.doc.getItem ("WF.LogActivityPS");
var WFActivityInPS = this.doc.getItem ("WFActivityInPS");
var WFActivityOutPS = this.doc.getItem ("WFActivityOutPS");
var WFLogDecisionPS = this.doc.getItem ("WF.LogDecisionPS");
var WFLogSubmitterPS = this.doc.getItem ("WF.LogSubmitterPS");
var WFLogCommentPS = this.doc.getItem ("WF.LogCommentPS");
var WFLogActivityDescPS = this.doc.getItem ("WF.LogActivityDescPS");
var Durr =((WFActivityOutPS-WFActivityInPS)/3600);
var json= {
"unid":"aa",
"Act":WFLogActivityPS,
"Fin":WFActivityOutPS,
"Durr":Durr,
"Decision":WFLogDecisionPS,
"Interv":WFLogSubmitterPS,
"Instruction":WFLogActivityDescPS,
"Comment":WFLogCommentPS
}
/*
*
* var wfdoc = new PSWorkflowDoc (document1, this);
histopry = wfdoc.getWFLog();
var getContact = JSON.parse(histopry );
*/ }

Careful. Your code is bleeding memory. Each Notes object you create (like the items) needs to be recycled after use calling .recycle().
There are a few ways you can go about it. The most radical would be to deploy the OpenNTF Domino API (ODA) which provides a handy document.toJson() function.
Less radical: create a helper bean and put code inside there. I would call a method with the document and an array of field names as parameter. This will allow you to loop through it.
Use the Json helper methods found in com.ibm.commons.util.io.json they will make sure all escaping is done properly. You need to decide if you really want arrays and objects mixed - especially if the same field can be one or the other in different documents. If you want them flat use item.getText(); otherwise use item.getValues() There's a good article by Jesse explaining more on JSON in XPages. Go check it out. Hope that helps.

If an input field contains several values that you want to transform into an array, use the split method :
var WFLogActivityPS = this.doc.getItem("WF.LogActivityPS").split(",")
// input : A,B,C --> result :["A","B","C"]

How to push object to array in angularjs?

This is my code
$scope.studentDetails=[];
$scope.studentIds={};
$scope.studentIds[0]{"id":"101"}
$scope.studentIds[1]{"id":"102"}
$scope.studentIds[2]{"id":"103"}
in the above code when i select student id:101 i got marks from services like
$scope.studentMarks={};
$scope.studentMarks[0]{"marks":"67"}
$scope.studentMarks[1]{"marks":"34"}
next i select student id:102 i got marks from services like
$scope.studentMarks={};
$scope.studentMarks[0]{"marks":"98"}
$scope.studentMarks[1]{"marks":"85"}
finally i want to store student details in to one array like
$scope.studentDetails=[{"id":"101","marks":[67,34]},{"id":"102","marks":[98,85]}]
using angularjs.

Seems like its more of a JS question than angular.
What about the Javascript push method?
$scope.studentDetails.push({id: 101, marks: [67, 34]});

You can use Array.push to add one object, or concat, to concat array into another array. See the references.

angularJS is just a library to extend Javascript. You push into an array just like you would any object in Javascript.
First off, you need to declare an array.
$scope.studentIds = []; // Array of student ids.
Then when you want to add, you push:
$scope.studentIds.push({id: "101"});

To do this naively you need to loop through the student ids and then loop through the marks object and adding it to your studentDetails object if the ids match:
var studentDetails = [];
for (var id in studentIds) {
var studentDetail = {}; // this will be a single student
var marks = [];
if (studentIds.hasOwnProperty(id)) {
for (var mark in studentMarks) {
if (studentMarks.hasOwnProperty(mark) && mark.id === id) {
studentDetail.id = id;
marks.push(mark.marks);
}
}
studentDetail.marks = marks;
}
studentDetails.push(studentDetail);
}
$scope.studentDetails = studentDetails;

JS/Jquery - using variable in json selector

I need to use a variable when selecting data from a json source like this.
The json is retrieved with jquery getJSON().
"prices":[{
"fanta":10,
"sprite":20,
}]
var beverage = fanta;
var beverage_price = data.prices.beverage;
Now beverage_price = 10
var beverage = sprite;
var beverage_price = data.prices.beverage;
Now beverage_price = 20
When I try to do it like in the examples, the script tries to look up the beverage entry in prices.
Thanks a lot!!

You can access it like:
var beverage = 'fanta';
var beverage_price = data.prices[0][beverage];

As VisioN mentioned in the comment, data.prices is an array, you need to access its first element with [0] which contains prices { "fanta":10, "sprite":20}
here is the working example : http://jsfiddle.net/2E8AH/
Or else you can make data.prices an object like below : (if it is in your control)
var data = {
"prices" :
{
"fanta":10,
"sprite":20,
}
};
and can access without [0] like this : http://jsfiddle.net/Y8KtT/1/

Dictionary equivalent data structure?

I'm working in JavaScript and want to keep a list of set km/mph approximations to hand. (I can't convert programmatically, I'm working with an external API that expects certain values, so it really does have to be a dictionary equivalent.)
Currently I'm using an object:
var KM_MPH = { 10: 16, 12: 20, 15: 24 };
Going from mph to km is pretty easy:
var km = KM_MPH[10];
How do I find mph, given km? Also, is an object the best data structure to use for this sort of thing in JavaScript? I'm more used to Python.

A basic JavaScript object is in fact the best choice here. To find a reverse mapping, you can do:
function mphToKM(val){
for(var km in KM_MPH){
if(KM_MPH[km] === val){
return km;
}
}
return null;
}
Or, if you anticipate having to do a lot of lookups, I would recommend having a secondary JS Object that is the mirror of the first
var mph_km = {};
for(var km in KM_MPH){
mph_km[KM_MPH[km]] = km;
}
// mph_km[16] ==> 10
I don't know if you are in fact doing this for conversion between kilometres per hour to miles per hour... if so, it seems to make more sense to just do the conversion directly instead of relying on a hash mapping of the values.
var conversionRate = 1.609344; // kilometres per mile
function kphToMPH(val){
return val / conversionRate ;
}
function mphToKPH(val){
return val * conversionRate;
}

You can use iterate over all entries to find to find your key
Mostly a dict is used to from key=>value
Alternatively you can have two lists
var km = [];
var mph = [];
with their corresponding indices mapped

This is much closer to a Dictionary data structure, since you can have dozens of elements:
var dictionary = [
{ key: 10, value: 12 },
{ key: 12, value: 20 },
{ key: 15, value: 24 }
];
Then you can also use some JavaScript Framework like jQuery to filter elements:
var element = $.filter(dictionary, function() {
return $(this).attr("key") == 10;
});
alert($(element).attr("value"));

Yes, the JavaScript object is the correct choice.
Create a second object to do the reverse lookup:
var i, MPH_KM = {};
for(i in KM_MPH) MPH_KM[KM_MPH[i]] = i;
var mph = MPH_KM[16];

The dictionary equivalent structure for a javascript object would look like this:
var dictionary = { keys:[], values:[] };
Above structure is an equivalent of
Dictionary(Of Type, Type) **For VB.Net**
Dictionary<Type, Type>) **For C#.Net**
Hope this helps!