Develop Reference

Javascript function to return page id's

I'm lookingfor a javascript function which returns the next value from an array on every function call.. I have created a script but i'm a little stuck now.. is there someone to help me?
My location:
resultLocation= "beugen";
This should be the identifier to get the correct array of id's. There will be more arrays with id''s for example resultLocation = "mill";
My array of Id's
var beugen = [];
beugen[0] = "140";
beugen[1] = "33";
beugen[2] = "121";
beugen[3] = "150";
beugen[4] = "52";
beugen[5] = "68";
beugen[6] = "70";
beugen[7] = "82";
beugen[8] = "15";
My function to return a value. (the next value should be shown on each call of getId (resultLoction)
getId = function(resultLocation) {
var arrayLength = beugen.length;
page = beugen;
for (var i = 0; i < arrayLength; i++) {
init_table(page[i]);
}
}
getId(resultLocation);
Now my function keeps on looping and calls the init_table(page[i]) as many times as there are id's in my array. It should get the first (140) on the first call of getId and the 2nd (33) on the next call, and if it reaches the end, it should start over again at the the top.
Maybe an array is not the best solution? I don't really know. Since there are multiple locations?

var i = -1;
function getId(){
i++;
if(i>beugen.length-1){
i=0;
}
init_table(beugen[i]);
return beugen[i];
}
or something like that might work if i understand the problem.

How to get the 'Value' using 'Key' from json in Javascript/Jquery

I have the following Json string. I want to get the 'Value' using 'Key', something like
giving 'BtchGotAdjust' returns 'Batch Got Adjusted';
var jsonstring=
[{"Key":"BtchGotAdjust","Value":"Batch Got Adjusted"},{"Key":"UnitToUnit","Value":"Unit To Unit"},]

Wow... Looks kind of tough! Seems like you need to manipulate it a bit. Instead of functions, we can create a new object this way:
var jsonstring =
[{"Key":"BtchGotAdjust","Value":"Batch Got Adjusted"},{"Key":"UnitToUnit","Value":"Unit To Unit"},];
var finalJSON = {};
for (var i in jsonstring)
finalJSON[jsonstring[i]["Key"]] = jsonstring[i]["Value"];
You can use it using:
finalJSON["BtchGotAdjust"]; // Batch Got Adjusted

As you have an array in your variable, you have to loop over the array and compare against the Key-Property of each element, something along the lines of this:
for (var i = 0; i < jsonstring.length; i++) {
if (jsonstring[i].Key === 'BtchGotAdjust') {
console.log(jsonstring[i].Value);
}
}
By the way, I think your variable name jsonstring is a little misleading. It does not contain a string. It contains an array. Still, the above code should give you a hint in the right direction.

Personally I would create a map from the array and then it acts like a dictionary giving you instantaneous access. You also only have to iterate through the array once to get all the data you need:
var objectArray = [{"Key":"BtchGotAdjust","Value":"Batch Got Adjusted"},{"Key":"UnitToUnit","Value":"Unit To Unit"}]
var map = {}
for (var i=0; i < objectArray.length; i++){
map[objectArray[i].Key] = objectArray[i]
}
console.log(map);
alert(map["BtchGotAdjust"].Value)
alert(map["UnitToUnit"].Value)
See js fiddle here: http://jsfiddle.net/t2vrn1pq/1/

accessing nested properties based on structure

Could anyone please give me an alternate syntax to the following
var id = '-JLxSeCPUCVN13FxifTY';
var ResultsContainer = results[id];
var i=0;
for(var k in ResultsContainer)
{
var TheArrayOfObjectsThatIneed = ResultsContainer[Object.keys(ResultsContainer)[i]];
console.log(TheArrayOfObjectsThatIneed);
//loop the TheArrayOfObjectsThatIneed do the processing
i++;
}
as you see in the image i have an array within an object within an object and i have no idea what the property names are but the structure is always the same {results:{id:{idthatidontknow:[{}]}}} and all i need is to access the arrays
the above code is working nicely but i am new to javescript and i was wondering if there is a nicer syntax and if i am doing it the right way

Perhaps something like this?
var id = '-JLxSeCPUCVN13FxifTY';
var ResultsContainer = results[id];
for(var k in ResultsContainer) {
if (ResultsContainer.hasOwnProperty(k)) {
var TheArrayOfObjectsThatIneed = ResultsContainer[k];
console.log(TheArrayOfObjectsThatIneed);
//loop the TheArrayOfObjectsThatIneed do the processing
}
}

concatenate an increment counter onto the end of an array selector within a json response loop

so I'm looping through a json response and I'm trying to use the counter (var i) to say data.newarray[i].time+i so with each loop the next array is chosen and the time also increases in number. So 1st loop will spit out data.newarray[0].time0 then data.newarray[1].time1 then data.newarray[2].time2 and so on. The bit that is currently failing is my concatenation time+i at the end. How do I format this to work?
var data = JSON.parse(xmlHTTP.responseText);
for(var i=0; i<data.newarray.length; i++)
{
alert(data.newarray[i].time+i);
}

You can access variable property names by using the quoted notation: obj['prop'] instead of obj.prop.
The solution is:
var data = JSON.parse(xmlHTTP.responseText);
for(var i=0; i<data.newarray.length; i++)
{
alert(data.newarray[i]['time'+i]);
}

Try something like this:
for(var i=0; i<data.newarray.length; i++) {
alert(data.newarray[i]['time'+i]);
}

JavaScript stop referencing object after pass it to a function

I know JavaScript passes Objects by reference and thus I'm having a lot of trouble with the following code:
function doGradeAssignmentContent(dtos) {
var x = 5;
var allPages = [];
var stage = new App.UI.PopUpDisplay.PopUpStageAssignmentGrader(null, that);// pass launch element
for(var i = 0; i < dtos[0].result.students.length; ++i) {
var pagesSet = [];
for(var j = 0; j < dtos[0].result.questions.length; ++j) {
var questionObject = jQuery.extend(true, {}, new Object());
questionObject = dtos[0].result.questions[j];
if(dtos[0].result.students[i].answers[j].assignmentQuestionId === questionObject.questionId) {// expected, if not here something is wrong
questionObject.answer = dtos[0].result.students[i].answers[j].studentAnswer;
questionObject.pointsReceived = dtos[0].result.students[i].answers[j].pointsReceived;
} else {
var theAnswer = findAssociatedStudentAnswer(questionObject.questionId, dtos[0].result.students[i].answers[j]);
if(theAnswer !== null) {
questionObject.answer = theAnswer.studentAnswer;
questionObject.pointsReceived = theAnswer.pointsReceived;
} else {
alert("Unexpected error. Please refresh and try again.");
}
}
pagesSet[pagesSet.length] = new App.UI.PopUpDisplay.StageAssignmentGradingPages[dtos[0].result.questions[j].questionType.charAt(0).toUpperCase() + dtos[0].result.questions[j].questionType.slice(1) + "QuestionAssignmentGradingPage"](j + 1, questionObject);
}
var studentInfo = {};
studentInfo.avatar = dtos[0].result.students[i].avatar;
studentInfo.displayName = dtos[0].result.students[i].displayName;
stage.addPageSet(pagesSet, studentInfo);
}
stage.launch();
}
First let me show you what the result (dtos) looks like so you can better understand how this function is parsing it:
The result (dtos) is an Object and looks something like:
dtos Array
dtos[0], static always here
dtos[0].result, static always here
dtos[0].questions Array
dtos[0].questions.index0 - indexN. This describes our Questions, each one is an Object
dtos[0].students Array
dtos[0].students[0]-[n].answers Array. Each student array/Object has an Answers array. Each student will have as many elements in this answers Array that there were questions in dtos[0].questions. Each element is an Object
Now what we do in this here is create this Object stage. Important things here are it has an array called "this.studentsPages". This array will ultimately have as many entries as there were students in dtos[0].students.
So we loop through this for loop disecting the dtos array and creating a pagesSet array. Here comes my problem. On the first iteration through the for loop I create this questionObject element. I also have tried just doing var questionObject = {}, but what you see now was just an attempt to fix the problem I was seeing, but it didn't work either.
So at the end of the first iteration of the outer for loop I call stage.addPageSet, this is what happens here:
var pageObject = [];
pageObject["questions"] = pageSet;
pageObject["displayName"] = studentInfo.displayName;
this.studentsPages[this.studentsPages.length] = pageObject;
if(this.studentsPages.length === 1) {// first time only
for(var i = 0; i < pageSet.length; ++i) {
this.addPage(pageSet[i]);
}
}
The important thing to take notice of here is where I add pageObject on to this.studentsPages which was an empty array before the first call. pageObject now has pageSet plus a little bit more information. Remember, pageSet was an Object and thus passed by reference.
On the next iteration of the for loop, when I hit this line:
questionObject.answer = dtos[0].result.students[i].answers[j].studentAnswer;
It goes wrong. This changes the local copy of questionObject, BUT it also changes the copy of questionObjec that was passed to addPageSet and added to the studentsPages array in the first iteration. So, if I only had 2 students coming in, then when all is said and done, studentsPages hold 2 identical Objects. This should not be true.
The problem is questionObject in the doGradeAssignmentContent function is keeping a reference to the Object created on the previous iteration and then overrides it on all subsequent iterations.
What can I do to fix this?
Thanks for the help!

With out having looked at it too closely I believe you need to change the following:
// Before:
var questionObject = jQuery.extend(true, {}, new Object());
questionObject = dtos[0].result.questions[j];
// After:
var questionObject = jQuery.extend(true, {}, dtos[0].result.questions[j]);
I didn't look too closely if there are other instances in the code where this needs to be applied, but the core concept is to utilize jQuery's deep copy to generate a duplicate of the object you do not wish to retain a reference to.