Develop Reference

jQuery Pull array from JSON response into new variable

Thank you for the help in advance. I am using a plugin which is expecting a JSON response to be an array not a object. Below is a sample of the JSON response I am getting
{
"instruments": [
{
"id": 3316,
"code": "WES",
"market_code": "ASX",
"name": "Wesfarmers Limited",
"currency_code": "AUD",
"pe_ratio": 16.38,
"nta": 4.44,
"eps": 2.55,
"current_price": 41.78,
"current_price_updated_at": "2017-10-26T16:10:09.000+11:00",
"sector_classification_name": "Retail Trade",
"industry_classification_name": "Food Retail",
"security_type": "Ordinary Shares",
"registry_name": "Computershare"
},
{
"id": 2955,
"code": "RIO",
"market_code": "ASX",
"name": "Rio Tinto Limited",
"currency_code": "AUD",
"pe_ratio": 14.95,
"nta": 27.77,
"eps": 4.66,
"current_price": 69.66,
"current_price_updated_at": "2017-10-26T16:10:11.000+11:00",
"sector_classification_name": "Non-Energy Minerals",
"industry_classification_name": "Other Metals/Minerals",
"security_type": "Ordinary Shares",
"registry_name": "Computershare"
},
],
"links": {}
}
The array I need to pull out into its own JSON object is the instruments array.
Now typically I know I would access that data via (if the response variable was called data) data.instruments[0].name as a example which would give me Wesfarmers limited
but if I want that entire array to sit in a new variable, which can then be parsed, how can I get that to happen?
Cheers

arr=new Array(data.instruments)

Indexing array values in an object in an IndexedDB

For a Chrome app, wich stores data in IndexedDB, i have a object like this:
var simplifiedOrderObject = {
"ordernumber": "123-12345-234",
"name": "Mr. Sample",
"address": "Foostreet 12, 12345 Bar York",
"orderitems": [
{
"item": "brush",
"price": "2.00"
},
{
"item": "phone",
"price": "30.90"
}
],
"parcels": [
{
"service": "DHL",
"track": "12345"
},
{
"service": "UPS",
"track": "3254231514"
}
]
}
If i store the hole object in an objectStore, can i use an index for "track", which can be contained multiple times in each order object?
Or is it needed or possibly better/faster to split each object into multiple objectStores like know from relational DBs:
order
orderitem
parcel
The solution should also work in a fast way with 100.000 or more objects stored.

Answering my own question: I have made some tests now. It looks like it is not possible to do this with that object in only 1 objectStore.
An other example object which would work:
var myObject = {
"ordernumber": "123-12345-234",
"name": "Mr. Sample",
"shipping": {"method": "letter",
"company": "Deutsche Post AG" }
}
Creating an index will be done by:
objectStore.createIndex(objectIndexName, objectKeypath, optionalObjectParameters);
With setting objectKeypath it is possible to address a value in the main object like "name":
objectStore.createIndex("name", "name", {unique: false});
It would also be possible to address a value form a subobject of an object like "shipping.method":
objectStore.createIndex("shipping", "shipping.method", {unique: false});
BUT it is not possible to address values like the ones of "track", which are contained in objects, stored in an array. Even something like "parcels[0].track" to get the first value as index does not work.
Anyhow, it would be possible to index all simple elements of an array (but not objects).
So the following more simple structure would allow to create an index entry for each parcelnumber in the array "trackingNumbers":
var simplifiedOrderObject = {
"ordernumber": "123-12345-234",
"name": "Mr. Sample",
"address": "Foostreet 12, 12345 Bar York",
"orderitems": [
{
"item": "brush",
"price": "2.00"
},
{
"item": "phone",
"price": "30.90"
}
],
"trackingNumbers": ["12345", "3254231514"]
}
when creating the index with multiEntry set to true:
objectStore.createIndex("tracking", "trackingNumbers", {unique: false, multiEntry: true});
Anyhow, the missing of the possibility to index object values in arrays, makes using indexedDB really unneeded complicated. It's a failure in design. This forces the developer to do things like in relational DBs, while lacking all the possibilities of SQL. Really bad :(

How do I access values in a d3 json file with nested array objects

Previously I was using a json file with the following format:
[{"lat":43.788458853157117,"lng":-79.282781549043008,"category":"volunteer","name":"Rita","url":"", "description":"xxx is a member of 13"},{"lat":43.7,"lng":-79.4,"category":"organization","name":"TCAN","url":"http://tcan.ca","description":"Lorem ipsum"}]
Now I am attempting to generate the json file from a Drupal site and am getting the following structure. How can I reference the lowest level fields. I have looked at examples using d3.net but have not found any that apply.
{
"organizations": [
{
"member": {
"field_category": "organization",
"body": "A network of organizations in Toronto devoted to climate change mitigation and adaptation.",
"URL": "xxx.ca",
"title": "Toronto Climate Action Network",
"field_lat": 43.7,
"field_long": -79.4
}
},
{
"member": {
"field_category": "abc",
"body": "xxx.",
"URL": "",
"title": "yyy",
"field_lat": 43.7,
"field_long": -79.28
}
}
]
}

Assuming that your data is stored in the variable data:
var bottom = data.organizations.map(function(d) { return d.member; });

How to create Backbone collection from following json array?

I am getting a following JSON(/users.json) which contains users:
[
[
{ "id": "43343", "project_id": "1", "username": "Amy" }
{ "id": "34244", "project_id": "1", "username": "Tommy" }
],
[
{ "id": "76575", "project_id": "2", "username": "Izzy" }
{ "id": "13322", "project_id": "2", "username": "Sam" }
],
{ "id": "09983", "project_id": "3", "username": "Max" }
]
When project has one user I get one user hash which is not in array.
I would like to build a Backbone collection with all users. How to do that?

You provide an array of arrays of users. So to fetch all users in the init method, you can give it data but as an array of users, i.e. you will flatten this original array of arrays once with underscore flatten method :
data = _(data).flatten(true);
Then the collection constructor will natively understand your json array.
But maybe you already do this transformation in the fetching method and this is not the problem you are facing..

If you have defined a collection (say userCollection) with a user model you should be able to simply do something like this:
var col;
$.getJSON("/users.json", function(data) {
col = new userCollection(data);
});
This would more likely be done in the fetch function of the collection, but the principle here is that you can pass an array of objects to a collection and it will marshal all from json to backbone models.

JSON parsing in JS

I am getting a JSON in response from server:
{
"width": "765",
"height": "990",
"srcPath": "http://192.168.5.13:8888/ebook/user_content/_ADMIN_/_MERGED_/1273.pdf",
"coverPage": "",
"documents": [
{
"index": "1",
"text": "Archiving Microsoft® Office SharePoint® Server 2007 Data with the Hitachi Content Archive Platform and Hitachi Data Discovery for Microsoft SharePoint",
"type": "doc",
"id": "HDS_054227~201106290029",
"children": [
{
"text": "Page 1",
"leaf": "true",
"pageLocation": "http://192.168.5.13:8888/ebook/user_content/_ADMIN_/_IMAGES_/HDS_054227~201106290029/image_1.png"
},
{
"text": "Page 2",
"leaf": "true",
"pageLocation": "http://192.168.5.13:8888/ebook/user_content/_ADMIN_/_IMAGES_/HDS_054227~201106290029/image_2.png"
}
]
},
{
"index": "11",
"text": "Brocade FCoE Enabling Server I/O Consolidation",
"type": "doc",
"id": "HDS_053732~201105261741",
"children": [
{
"text": "Page 1",
"leaf": "true",
"pageLocation": "http://192.168.5.13:8888/ebook/user_content/_ADMIN_/_IMAGES_/HDS_053732~201105261741/image_1.png"
},
{
"text": "Page 2",
"leaf": "true",
"pageLocation": "http://192.168.5.13:8888/ebook/user_content/_ADMIN_/_IMAGES_/HDS_053732~201105261741/image_2.png"
}
]
}
]
}
And I want to get pagelocation of the children.
Can anyone tell me how to do this?
Hi
i also want to get indexes from this and then want to get pagelocations of that particular children. Can you tell me how would i do that?
And also when i when i am getting indexes array it is returning me ,, only and not the index nos.
I am using following code for that :
indexes=response.documents.map(function(e){ return e.children.index; })
Thanks & Regards

If you're interested in simply retrieving all the page locations, you can do it using filter:
var locations = [];
json.documents.forEach(function(e,i) {
e.children.forEach(function(e2,i2) {
locations.push(e2.pageLocation);
)}
});
// returns flat array like [item1,item2,item3,item4]
You can get an array of arrays using map:
var locations = [];
var locations = json.documents.map(function(e) {
return e.children.map(function(e2) {
return e2.pageLocation;
});
});
// returns 2-dimensional array like [[item1,item2],[item1,item2]]

Your json response is an appropriate javascript object So you can access all elements of the object like you do as in back end.
here, you have an array of object of the type documents and each document object has array of objects of the type children. so
syntax would be
myjson.documents[0].children[0].pagelocation
( = http://192.168.5.13:8888/ebook/user_content/_ADMIN_/_IMAGES_/HDS_054227~201106290029/image_1.png)
will give you the very first page location..
and so on