I have a parse data model like...
Parent
------
children - Array of pointers to Child objects
I'm trying to create a query that says...
Find all Parents where the children array contains the specific Child object.
It's sort of the opposite of this function from the docs.
query.containedIn("playerName", ["Jonathan Walsh", "Dario Wunsch", "Shawn Simon"]);
// note you can also do this with object pointers which is EXACTLY opposite to what I want.
This will find all the players where the playerName is contained in the given array.
I want this but I want to give a value and that value to be in the array for the key.
I imagine it's something like...
query.contains("children", someChildObject);
but the docs for contains shows it only works for substrings of strings.
How would I do what I'm looking for?
You should use query.equalTo for key with an array type.
Try query like following:
var ChildClass = Parse.Object.extend('ChildClass');
var childObj = new ChildClass();
childObj.id = 'objId';
// you don't need to do above if you already have the object.
query.equalTo("children", childObj);
...
ref. Queries on Array Values
Related
I have the mapping of abbreviation and full name as follow:
object = {"TSLA":"TESLA INC.","GOOG":"GOOGLE INC.","APPL":"APPLE INC.","AMZN":"AMAZON CORPORATION", "MSFT":"MICROSOFT CORPORATION"}
as an output of function i get the following array:
array = ["AMZN","APPL"]
I want to display the values of the associated keys as follows:
output_array = ["AMAZON CORPORATION", "APPLE INC."]
Note that, the actual object has more key: value pairs
Using IndexOf() I can replace one value. However, I believe there must be a way of mapping the array elements to replace the values at once.
Since I am new to JS, I would appreciate any suggestion.
array.map(abbr => object[abbr]) does the job; it iterates over the array rather than the object, which is more efficient as the object already is a lookup table with the right keys - you are right, there is no need to use indexOf which uses a linear search.
I have a React application which handles rooms and their statistics.
Previously, I had the code set up to pass as props to the next component:
the raw statistics (not a concern for the question)
an array of all the rooms set up as follows
I figured it would be simpler for me, though, to have the list of all rooms as an associative array where the keys of each element is the same as the ID it contains. To do that, I utilized a code similar to this in a for loop:
roomsList[rooms[v].ID] = rooms[v];
So that the result would be:
[a001: {...}, a002: {...}, ...]
I then proceeded to pass this style of array, and not the standard one with a numeric index, as a prop to the next component as such:
<StatsBreakdown stats={computedStats.current} roomsList={roomsList} />
BUT
Now, the next component sees that prop as an empty array.
Even more weirdly, if I initialize that roomsList array with a random value [0] and then do the same process, I end up with:
I cannot cycle through the array with .map, and, according to JS, the length is actually 0, it's not only Google Chrome.
Is there something I'm missing about the way JSX, JS or React work?
Your original roomsList was an array of objects, whose indices were 0,1,2 etc. roomsList[rooms[v].ID] = rooms[v]; implies you are inserting elements not using a number but an alphanumeric string. Hence your resulting array is no longer an array but an object.
So we can cycle over the object using Object.keys().
const renderRoomDets = Object.keys(roomsList).map(room => {
roomOwner = roomsList[room].owner_id;
return (
<div>
<p>{`Room Owner ${roomOwner}`}</p>
</div>
);
});
But I believe your original form is ideal, because you are reaping no special benefits from this notation.
A better alternative maybe using .find() or .findIndex() if you want iterate over an array based on a specific property.
const matchedRoom = roomsList.find(room => room.ID === 'Srf4323')
Iterate the new array using its keys not indexes.
Or even better store your data in an actual object instead of an array since you're using strings for ids.
First define your object like so:
let data = {};
Then start adding records to it. I'd suggest deleting the ID attribute of the object since you're storing it in the key of your record, it's redundant, and it won't go anywhere unless u delete the entry.
data[ID] = row;
To delete the ID attribute (optional):
row.ID = null;
delete row.ID;
Then iterate through it using
for(let key in data){}
Basically I have a complex object that retrieves the GPT API (google publisher tag) with this function:
googletag.pubads().getSlots();
The object value is something like this:
I need to know if there is a way to compare the value of each property with an X value without getting a problem of recursivity (because the object is huge and i need to to that validation several times)
Also, I tried to convert that object into a JSON with JSON.stringify(), and then tried to get the value with a regex, faster, but with this option, I have the problem with Cyclic Object Value.
Any suggestions ?
it's more simple. try it to convert it into an array and later use a filter for comparative with your value.
var objGoogle = {};
var arrayObjectGoogle = [objGoogle];
var filter = arrayObjectGoogle.filter(function(obj){
obj.yourAttr == yourValue; });
this will give you a second array with the values found it. later, index the array for pick up the value do you need.
I want to get the features from my layer. So I'm requesting WMSGetFeatureInfo method after a successful request for GetFeatureInfo on my layer.
The returned object is structured like this:
I can read values like BEVDICHTE with var bevdichte = features.BEVDICHTE and so on.
But when I want to get the value of the_geom with var the_geom = features.the_geom it returns an object. Yes it is nested so this is intended but my question is how to get the value ol.geom.MultiPoint
from the_geom?
EDIT:
Unfortunately var target = features.the_geom['actualEventTarget_']; will just return another 'actualEventTarget_' object. This is because the the_geom object is nested into infinity. I attached another screenshot to describe my problem. There are many more nested eventTargets following. Yet I was not able to get the property ol.geom.MultiPolygon.
To access a nested array, just use brackets: '[ ]'
var nestedArray = [[1,2], [3,4]];
var nestedArrayValue = nestedArray[0][0];
// --> returns 1
With your example:
var target = features.the_geom['actualEventTarget_']
By the way, from the looks of it var the_geom = features.the_geom doesn't seem like an array. It has keys, mapped to a value, are you sure this is an array, not an object?
I have a JSON collection produced from an object graph. Shown below is an example value. I am having trouble accessing the nested 'Type' object to retrieve any of it's values.
[{"Id":1,"Name":"My Name","Type":{"Id":1,"Name":"my Value"}}]
I am using a JS component that has a property that can be assigned a value similar to below.
myProperty: Type.Name, //Not working
Can someone recommend how I set this value?
What you have is a JavaScript array, not an object, and certainly not JSON. So if you have
var arr = [{"Id":1,"Name":"My Name","Type":{"Id":1,"Name":"my Value"}}]
you'd need to index it, and grab the Type object off of that.
var typeName = arr[0].Type.Name;