Create / Update multiple objects from one API response - ember.js

all new jsfiddle: http://jsfiddle.net/vJxvc/2/
Currently, i query an api that will return JSON like this. The API cannot be changed for now, which is why I need to work around that.
[
{"timestamp":1406111961, "values":[1236.181, 1157.695, 698.231]},
{"timestamp":1406111970, "values":[1273.455, 1153.577, 693.591]}
]
(could be a lot more lines, of course)
As you can see, each line has a timestamp and then an array of values. My problem is, that i would actually like to transpose that. Looking at the first line alone:
{"timestamp":1406111961, "values":[1236.181, 1157.695, 698.231]}
It contains a few measurements taken at the same time. This would need to become this in my ember project:
{
"sensor_id": 1, // can be derived from the array index
"timestamp": 1406111961,
"value": 1236.181
},
{
"sensor_id": 2,
"timestamp": 1406111961,
"value": 1157.695
},
{
"sensor_id": 3,
"timestamp": 1406111961,
"value": 698.231
}
And those values would have to be pushed into the respective sensor models.
The transformation itself is trivial, but i have no idea where i would put it in ember and how i could alter many ember models at the same time.

you could make your model an array and override the normalize method on your adapter. The normalize method is where you do the transformation, and since your json is an array, an Ember.Array as a model would work.

I am not a ember pro but looking at the manual I would think of something like this:
a = [
{"timestamp":1406111961, "values":[1236.181, 1157.695, 698.231]},
{"timestamp":1406111970, "values":[1273.455, 1153.577, 693.591]}
];
b = [];
a.forEach(function(item) {
item.values.forEach(function(value, sensor_id) {
b.push({
sensor_id: sensor_id,
timestamp: item.timestamp,
value: value
});
});
});
console.log(b);
Example http://jsfiddle.net/kRUV4/
Update
Just saw your jsfiddle... You can geht the store like this: How to get Ember Data's "store" from anywhere in the application so that I can do store.find()?

Related

MongoDB: Aggregation using $cond with $regex

I am trying to group data in multiple stages.
At the moment my query looks like this:
db.captions.aggregate([
{$project: {
"videoId": "$videoId",
"plainText": "$plainText",
"Group1": {$cond: {if: {$eq: ["plainText", {"$regex": /leave\sa\scomment/i}]},
then: "Yes", else: "No"}}}}
])
I am not sure whether it is actually possible to use the $regex operator within a $cond in the aggregation stage. I would appreciate your help very much!
Thanks in advance
UPDATE: Starting with MongoDB v4.1.11, there finally appears to be a nice solution for your problem which is documented here.
Original answer:
As I wrote in the comments above, $regex does not work inside $cond as of now. There is an open JIRA ticket for that but it's, err, well, open...
In your specific case, I would tend to suggest you solve that topic on the client side unless you're dealing with crazy amounts of input data of which you will always only return small subsets. Judging by your query it would appear like you are always going to retrieve all document just bucketed into two result groups ("Yes" and "No").
If you don't want or cannot solve that topic on the client side, then here is something that uses $facet (MongoDB >= v3.4 required) - it's neither particularly fast nor overly pretty but it might help you to get started.
db.captions.aggregate([{
$facet: { // create two stages that will be processed using the full input data set from the "captions" collection
"CallToActionYes": [{ // the first stage will...
$match: { // only contain documents...
"plainText": /leave\sa\scomment/i // that are allowed by the $regex filter (which could be extended with multiple $or expressions or changed to $in/$nin which accept regular expressions, too)
}
}, {
$addFields: { // for all matching documents...
"CallToAction": "Yes" // we create a new field called "CallsToAction" which will be set to "Yes"
}
}],
"CallToActionNo": [{ // similar as above except we're doing the inverse filter using $not
$match: {
"plainText": { $not: /leave\sa\scomment/i }
}
}, {
$addFields: {
"CallToAction": "No" // and, of course, we set the field to "No"
}
}]
}
}, {
$project: { // we got two arrays of result documents out of the previous stage
"allDocuments" : { $setUnion: [ "$CallToActionYes", "$CallToActionNo" ] } // so let's merge them into a single one called "allDocuments"
}
}, {
$unwind: "$allDocuments" // flatten the "allDocuments" result array
}, {
$replaceRoot: { // restore the original document structure by moving everything inside "allDocuments" up to the top
newRoot: "$allDocuments"
}
}, {
$project: { // include only the two relevant fields in the output (and the _id)
"videoId": 1,
"CallToAction": 1
}
}])
As always with the aggregation framework, it may help to remove individual stages from the end of the pipeline and run the partial query in order to get an understanding of what each individual stage does.

How to give a route a model that contains both sides of hasMany and belongsTo relationship?

I have successfully managed to get this rather ember-unfriendly API result into a parent/child pair of models called 'connector' and 'pin', where the connector is the parent and an array of pins is the children. I have a hasMany('pin') on the connector model and belongsTo('connector') on the pins.
{
"Connector" : {
"ConnectorID" : "2015-11-30T16:34:34.217",
"ConnectorName" : "D38999/20WA98SN"
},
"Pins" : [{
"ConnectorID" : "2015-11-30T16:34:34.217",
"PinName" : "A"
}, {
"ConnectorID" : "2015-11-30T16:34:34.217",
"PinName" : "B"
}, {
"ConnectorID" : "2015-11-30T16:34:34.217",
"PinName" : "C"
}
]
}
So far, all is well, I think. I am now faced with getting all of the data from both to appear on a route called 'connector'. I can't quite wrap my mind around how to chain the promises so that I can get both
this.get('store').findRecord('connector', params.connector_id);
and
this.get('store').findRecord('connector', params.connector_id).findAll(???);
It seems like I am fighting an up-hill battle on this relationship. I wish I could just get Ember to treat the array of pins as it would any other singular data type and get/save the data with the record. Am I think of this correctly?
The answer to "I wish I could just get Ember to treat the array of pins..." comment was solved with
ember g transform array
Tips to this post:
How to represent arrays within ember-data models?.
I am pretty happy with the final code after I cleaned up all of my experiments. I didn't have to call
App.register("transform:array", DS.ArrayTransform);
At least I didn't have to write the call myself.

How to get from CouchDB only certain fields of certain documents with a single request?

create a view that return only a subset of values from a document, each with its key and value within a json string. like if one given view returns a document as this following, Is it possible to get some fields information for a one request? thank you
{
"total_rows":10,
"offset":3,
"rows":[{
"id":"doc1",
"key":"abc123",
"value": {
"_id":"aaaa",
"_rev":"bbb",
"field1":"abc",
"field2":"bcd",
"field3":"cde",
"field4":"123",
"field5":"789",
"field6":"aa#email.com",
"field7":"ttt",
"field8":"iii",
"field9":[{
"field91":"tyui",
"field92":"55555"
}],
"field10"::"0000",
"field11"::"55555",
"field12"::"0030".........
}
}
I just want to create a view that returns some fields only the following:
{
"field1":"abc",
"field2":"bcd",
"field3":"cde",
"field4":"123",
"field5":"789",
"field6":"aa#email.com",
"field7":"ttt",
"field8":"iii",
"field9":[{
"field91":"tyui",
"field92":"55555"
}]
}
A map function that emits a new document with selected fields only. As an example, let's map field1 (a string) and field9 (an array) only:
function map(doc) {
emit(doc._id, {
field1: doc.field1,
field9: doc.field9
});
}
In the above example, each document will be fired with a key being the original doc ID and the value being the mapped fields you require.
This is useful if you are planning to add a reduce function later.
Depending on your use case, you may just want to emit the mapped objects:
function map(doc) {
emit({
field1: doc.field1,
field9: doc.field9
});
}
Please see http://guide.couchdb.org/draft/views.html
The documentation on building data views is pretty good, you can discover a lot by experimenting..

Restless - "objects" wrapper

I'm working with Restless and as stated in the documentation, returning Model.objects.all() produces something like this:
{
"objects": [
{
"id": 1,
"title": "First Post!",
"author": "daniel",
"body": "This is the very first post on my shiny-new blog platform...",
"posted_on": "2014-01-12T15:23:46",
},
{
# More here...
}
]
}
This works fine. However, I don't want the "objects" wrapper to be here. My front-end code expects an array.
Is there any way of telling Restless not to wrap the array?
You can do this by overriding method Resource.wrap_list_response(). Default implementation just wraps data in a dictionary (within the objects key), you can modify this to return data unchanged.

How do Django Fixtures handle ManyToManyFields?

I'm trying to load in around 30k xml files from clinicaltrials.gov into a mySQL database, and the way I am handling multiple locations, keywords, etc. are in a separate model using ManyToManyFields.
The best way I've figured out is to read the data in using a fixture. So my question is, how do I handle the fields where the data is a pointer to another model?
I unfortunately don't know enough about how ManyToMany/ForeignKeys work, to be able to answer...
Thanks for the help, sample code below: __ represent the ManyToMany fields
{
"pk": trial_id,
"model": trials.trial,
"fields": {
"trial_id": trial_id,
"brief_title": brief_title,
"official_title": official_title,
"brief_summary": brief_summary,
"detailed_Description": detailed_description,
"overall_status": overall_status,
"phase": phase,
"enrollment": enrollment,
"study_type": study_type,
"condition": _______________,
"elligibility": elligibility,
"Criteria": ______________,
"overall_contact": _______________,
"location": ___________,
"lastchanged_date": lastchanged_date,
"firstreceived_date": firstreceived_date,
"keyword": __________,
"condition_mesh": condition_mesh,
}
}
A foreign key is simple the pk of the object you are linking to, a manytomanyfield uses a list of pk's. so
[
{
"pk":1,
"model":farm.fruit,
"fields":{
"name" : "Apple",
"color" : "Green",
}
},
{
"pk":2,
"model":farm.fruit,
"fields":{
"name" : "Orange",
"color" : "Orange",
}
},
{
"pk":3,
"model":person.farmer,
"fields":{
"name":"Bill",
"favorite":1,
"likes":[1,2],
}
}
]
You will need to probably write a conversion script to get this done. Fixtures can be very flimsy; it's difficult to get the working so experiment with a subset before you spend a lot of time converting the 30k records (only to find they might not import)