I have an object and within this object I have items and one of the items is an array which also contains objects. A sample of the data is shown below.
I am using knockout to bind this data to the view so I think I need to implement a double loop for returning the objects and the objects within the child array to be able to bind them in the view.
Sample data:
"singers": {
"ijiyt6ih": {
"id": ObjectId('ijiyt6ih'),
"name": "John",
"songs": [
{
"id": ObjectId('okoiu8yi'),
"songName": "Hello There",
"year": "1980"
},
{
"id": ObjectId('sewfd323'),
"songName": "No More",
"year": "1983"
}
]
},
"98usd96w": {
"id": ObjectId('98usd96w'),
"name": "Jack",
"songs": [
{
"id": ObjectId('iew342o3'),
"songName": "Hurry Up",
"year": "1985"
}
]
}
}
I need to find a way to appropriately loop through this so that I can modify the returned data to bind it to the viewModel using knockout.
Here is how my viewModel looks like:
singersViewModel = function(data) {
var self = {
singerId: ko.observable(data.id),
singerName: ko.observable(data.name),
songName: ko.observable(...),
songYear: ko.observable(...)
};
I am not sure if I will have to return two different sets of data or not.
As for the looping. I was able to loop and return the list of singers to display on the page but I am not able to get the list of songs displayed within each singer.
Here is my loop so far:
var self = {},
singer,
tempSingers = [];
self.singers = ko.observableArray([]);
for (singer in singers) {
if (singers.hasOwnProperty(singer)) {
tempSingers.push(new singersViewModel(singers[singer]));
}
}
self.singers(tempSingers);
I tried to duplicate the same type of loop for songs within this loop but i would get an error using hasOwnProperty because songs is an array.
In the included snippet you can see how you can map the original data to a viewmodel that can be bound to a view.
I've left the ids as regular properties, and converted the names into observables, so thatthey can be edited. At the bottom you can see the current viewmodel state.
There is also a sample view which iterates the list of singers, and also the list of song within each singer.
As you can see I'm implementing the solution using mapping. For mapping you need to implement a callback that receives each original object and returns a new one with a new structure. For example this part of the code
_.map(_singers, function(singer) {
return {
id: singer.id,
name: ko.observable(singer.name),
// ... songs:
})
iterates over each singer (the sample data in the question), and for each one creates a new object with the id, an observable which includes the name (and the mapping of songs, which I don't show in this fragment).
NOTE: I'm using lodash, but many browsers support map natively as an array function
var ObjectId = function (id) { return id; }
var singers = {
"ijiyt6ih": {
"id": ObjectId('ijiyt6ih'),
"name": "John",
"songs": [
{
"id": ObjectId('okoiu8yi'),
"songName": "Hello There",
"year": "1980"
},
{
"id": ObjectId('sewfd323'),
"songName": "No More",
"year": "1983"
}
]
},
"98usd96w": {
"id": ObjectId('98usd96w'),
"name": "Jack",
"songs": [
{
"id": ObjectId('iew342o3'),
"songName": "Hurry Up",
"year": "1985"
}
]
}
};
var SingersVm = function(_singers) {
var self = this;
self.singers = _.map(_singers, function(singer) {
return {
id: singer.id,
name: ko.observable(singer.name),
songs: _.map(singer.songs, function(song) {
return {
name: ko.observable(song.songName),
id: song.id
};
})
};
});
return self;
};
var vm = new SingersVm(singers);
//console.log(vm);
ko.applyBindings(vm);
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/3.10.1/lodash.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/3.2.0/knockout-min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div data-bind="foreach: singers">
<div>
<input data-bind="value: name"/> (<span data-bind="text: id"></span>)
<ul data-bind="foreach:songs">
<li>
<input data-bind="value: name"/> (<span data-bind="text: id"></span>)
</li>
</ul>
</div>
</div>
<pre data-bind="html: ko.toJSON($root,null,2)">
</pre>
Related
I am trying to update through useState a child object with an additional object. I created an example to make this more clear :
https://codesandbox.io/s/affectionate-wescoff-u01x0?file=/src/App.js
The example object looks like :
{
"id": 123,
"books": {
"book": {}
}
}
When I push more data in I want it to look like this :
{
"id": 123,
"books": {
"book": {
"name": "Sirens of Titan",
"author": "Kurt Vonnegut"
},
"book": {
"name": "The Hobbit",
"author": "J.R.R. Tolkein"
}
}
}
At this stage I have it pretty messed up and it looks like :
{
"id":123,
"books":[
{
"0":{
"book":{
},
"sampleData1":{
"book":{
"name":"Sirens of Titan",
"author":"Kurt Vonnegut"
}
}
},
"sampleData2":{
"book":{
"name":"The Hobbit",
"author":"J.R.R. Tolkein"
}
}
}
]
}
This is the way I set that broken object :
const [main, setMain] = useState(library);
function addNestedObj() {
setMain({ ...main, books: [{ ...main.books, sampleData1 }] });
}
Just take the destructuring a stage further:
setMain({...main, kids: [...main.kids, secondObj]})
The books property of your library object was an object, not an array. This might have been necessary but I guessed that it isn't since your book objects already have a name property, so they don't need a separate key.
With that change, you can modify your setMain function to add the book property of the sampleData to the books property of your state:
setMain({ ...main, books: [...main.books, sampleData1.book] });
I've added these changes in a fork of your CodeSandbox: https://codesandbox.io/s/modest-fog-byegh?file=/src/App.js
I am trying to use underscoreJs to manipulate a JavaScript object and having problems doing so.
Here is my example
var data = {
"label": "SomeName",
"parent": [{
"id": "parentId",
"resources": [{
"name": "ID1NAME",
"calls": [
"user_get", "user2_post", "user3_delete"
]
}, {
"name": "ID2",
"calls": [
"employee1_get", "employee2_delete", "employee3_update"
]
}]
}]
};
var res = _(data).chain().
pluck('parent').
flatten().
findWhere(function(item){
item === "user_get"
}).
value();
console.log(res);
Using an element which is a part of data.parent.calls[] (example : "user_get") I would like to extract its parent object, i.e. data.parent[0].
I tried above but always get undefined. I appreciate any help on this.
One of the problems you're having is your use of _.pluck. If you execute _.pluck over an object, it'll go over the keys of the object trying to retrieve the property you specified as the second argument (in this case, 'parent'). 'label' is a string and 'parent' is an array so thus the array that you get as a result is [undefined, undefined]. The rest will then go wrong.
One solution could be as follows:
function findCallIndexInParent(call, parent) {
return _.chain(parent)
.pluck('resources')
.flatten()
.findIndex(function (obj) {
return _.contains(obj.calls, call);
})
.value();
}
function findCall(call, data) {
var parent = data.parent;
return parent[findCallIndexInParent(call, parent)];
}
console.log(findCall('user_get', data));
findCall is just a convenient method that will pass the parent property of data to findCallIndexInParent (that will retrieve the index where call is) and return the desired object with the parent array.
Lodash (a fork of underscore) provides a method to get the property of an object that would have come really handy in here (sadly, underscore doesn't have it).
The explanation of findCallIndexInParent is as follows:
Chain the parent list
pluck the resources array
As pluck maps, it returns a list of lists so a flatten is needed.
Find the index of the element which calls contains call
Return the value (the index) of the object that contains call within parent.
Here's the fiddle. Hope it helps.
This would seem to do the trick.
function findByCall(data, call) {
return _.find(data.parent, function(parent) { //From data.parent list, find an item that
return _.some(parent.resources, function(resource) {//has such parent.resource that it
return _.includes(resource.calls, call); //includes the searched resource.calls item
});
});
}
//Test
var data = {
"label": "SomeName",
"parent": [{
"id": "parentId",
"resources": [{
"name": "ID1NAME",
"calls": [
"user_get", "user2_post", "user3_delete"
]
}, {
"name": "ID2",
"calls": [
"employee1_get", "employee2_delete", "employee3_update"
]
}]
}]
};
console.log(findByCall(data, 'user_get'));
<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore.js"></script>
If I understand correctly, you want to get the index of the element in the parent array which has any resource with the specified call.
data = {
"label": "SomeName",
"parent": [{
"id": "parentId",
"resources": [{
"name": "ID1NAME",
"calls": [
"user_get", "user2_post", "user3_delete"
]
}, {
"name": "ID2",
"calls": [
"employee1_get", "employee2_delete", "employee3_update"
]
}]
}]
}
// find the index of a parent
const index = _.findIndex(data.parent, parent =>
// that has any (some) resources
_.some(parent.resources, resource =>
// that contains 'user_get' call in its calls list
_.contains(resource.calls, 'user_get')
)
)
console.log(index) // 0
<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script>
If you want to find the actual parent object, use find instead of findIndex
If you want to find all parent objects matching this call, use filter instead of findIndex
I'm trying to add an object into an empty array that is stored in one of my collections.
Currently this is how I have my collection setup:
[
{
"name": "user_added",
"DRGs": []
},
...
]
How can I insert an object into the collection so that it looks like this;
[
{
"name": "user_added",
"DRGs": [
{
"code": "491",
"name": "Back & neck procedures"
}
]
},
...
]
Check out $push documentation.
You should be able to accomplish your goal with the following:
var collectionName = 'users'; // or whatever your actual collection name is
var objectToPush = {
code: "491",
name: "Back & neck procedures"
};
db.collection(collectionName).updateOne(
{"name": "user_added"},
{ $push: { "DRGS": objectToPush }}
);
I'm trying to add data to the end of an observable array but it's just not working as expected. I bet it is something minor but I just can't get my head around it.
What I am doing:
self.businesses = ko.observableArray();
function Business(business) {
var self = this;
self.BusinessID = ko.observable(business.BusinessID );
self.Type = ko.observable(business.Type);
self.Location = ko.observable(business.Location);
}
/*ajax get array of businesses as follows:
[
{
"$id": "1",
"BusinessID ": 62,
"Type": "Data",
"Location": "Data"
},
{
"$id": "2",
"BusinessID ": 63,
"Type": "Data",
"Location": "Data"
},
{
"$id": "3",
"BusinessID ": 64,
"Type": "Data",
"Location": "Data",
} ]
*/
var mappedBusinesses = $.map(data, function (business) { return new Business(business) });
self.businesses(mappedBusinesses);
This all works as expected and the obersablearray is populated.
However if I go to add another business, it wont work. For example, if I call the ajax that returns this (as newBusiness):
{
"$id": "1",
"BusinessID ": 68,
"Type": "Data",
"Location": "Data"
}
and I do:
self.businesses().push(newBusiness);
It adds to the array as an "Object" not a Business. So I thought I would do:
var bus = $.map(newBusiness, function (business) { return new Business(business) });
self.businesses().push(bus);
But I get the error in the JS console "Uncaught TypeError: Cannot read property 'BusinessID' of null
So I made a new var and added the brackets: [] in and it adds to the observable array but not as a "Business" object but rather as an "Array[1]" object at the end and this doesn't function as per the others. Code as follows:
var newBus = {
BusinessID: newBusiness.BusinessID,
Type: newBusiness.Type,
Location: newBusiness.Location
}
var bus = $.map(newBus, function (business) { return new Business(business) });
self.businesses().push(bus);
As mentioned this adds to the observable array but doesn't actually add as a "business" object but rather as an "array[1]" object.
I bet it's something so basic but just can't get it working!
Argh I knew it would be simple!
It was posting the whole array to the ObservableArray...not just the object.
The fix:
self.businesses.push(newBusiness[0])
Had to add the [0] in to get it to push the actual data into the array, not the object!
Thanks for the answers!
You're evaluating the array with your push:
self.businesses().push(newBusiness);
Observable Arrays have their own array functions, you should just do this (no parens):
self.businesses.push(newBusiness);
See this page: http://knockoutjs.com/documentation/observableArrays.html
i have some json objects and some of them have some other objects inside them.
if i leave only the json obj that don't have other obj inside them and then apply the template, everything goes well, i get, in this case 3 li elements.
but if i grab the original json obj the results are a bit wired. I believe i need to do a each statement to iterate through each sub json obj from inside each main one
maybe i am a bit confuse so here is some code.
i have some json data like this:
{
"msg_id":"134",
"message":"Nick",
"comment":[
{
"com_id":"9",
"comment":"test",
},
{
"com_id":"10",
"comment":"testtt",
},
{
"com_id":"11",
"comment":"testtttt",
}]
},
{
"msg_id":"134",
"message":"Nick",
},
{
"msg_id":"134",
"message":"Nick",
}
and i am trying to arive at something like this:
Nick
test
testtt
testtttt
Nick
Nick
i've created a template like this:
function messagesTamplate(data)
{
$.each(data, function(index, obj)
{
msg += template.replace( /{{message}}/ig , obj.message );
if(obj.comment) {
$.each(obj.comment, function(key, val)
{
msg += template.replace( /{{comment}}/ig , val.comment );
});
}
});
return msg;
}
then i just append this to the main ul.
thanks
data needs to be an array (see the enclosing [])
var data = [{
"msg_id": "134",
"message": "Nick",
"comment": [{
"com_id": "9",
"comment": "test",
}, {
"com_id": "10",
"comment": "testtt",
}, {
"com_id": "11",
"comment": "testtttt",
}]
}, {
"msg_id": "134",
"message": "Nick",
}, {
"msg_id": "134",
"message": "Nick",
}]
is just this in mustache templates:
{{#data}} //loop through all data
{{message}} //pick out the "message" per iteration
{{#comment}} //loop through all comments in an iterated item
{{comment}} //pick out the comment
{{/comment}}
{{/data}}