I am retrieving specific data as an array from firestore, the value is the there on the console.log(), but i cant seems to retrieve the specific data from the array itself,
here's my event.ts
import { Event } from '../../models/event';
invitedEvents: Event[] = [];
this.invitedEvents = invitedEvents;
console.log(invitedEvents, invitedEvents.name);
on console.log()
as you can see the invitedEvents.name return value of undefined, i'm sure you guys know the proper way of retrieving the value of name, send help.
The object is in the array, so you have to access object from array first invitedEvents[0]
console.log(invitedEvents, invitedEvents[0].name);
Here you have to invitedEvents is an array. So if you need to access you can't directly like invitedEvents.name like this, here is the few ways to access.
for(let item of invitedEvents){
console.log("Data",item);
console.log("Specific Name",item.name);
}
This example is used to print multiple values.
If you have only one value.Simply do like this.
console.log("Specific Name Second way", invitedEvents[0].name);
I hope its helps you.
Thanks,
Muthu
Related
I'm trying to convert an Object array into an array without use "let item of array" on html, I already google a lot but nothing that I find works.
Why I don't use loops? because I pretend to display data inside a page that comes from a liteSQL database, so all the data that I extract from that it's an Object and sure I can display the data without issues if I use a loop like "let item of array" but in this case I just want to show information on the HTML like item.name or item.avatar
Thanks in advance for any help, If you guys need more information please let me know.
The database have students so every array have: name, age, avatar, etc, so I try to show some like a profile after they tap the name on the list
EDIT:
What you are receiving from your server is an array of objects.
array of objects ->
[{
key1:vlaue1,
key2:value2
},
{
key1:vlaue1,
key2:value2
}]
You refer the values here by using array[0]['key1'] array[0]['key2'] and so on
In your case, you are receiving only one object in the array, so simply use array[0].name array[0].age and so on
Thanks for the help, I actually found the solution by my self, I just need to use:
item: array = <array>{};
in order to use my object array as a simple array items without any loop on html
I am trying to update the data in a document in Cloud Firestore with an array however whenever I try to do this I get an error: Terminating app due to uncaught exception 'FIRInvalidArgumentException', reason: 'Unsupported type: __SwiftValue (found in field upvotes)'. I would really appreciate it if someone could help me understand what I am doing wrong and how I can fix this. Thanks. Code is below.
Code for updating array-
db.collection("forum").document(data[0].id!).setData(["upvotes": data[0].upvotes!.remove(at: data[0].upvotes!.firstIndex(of: MainView.username ?? "Anonymous")!)])
You must pass an array to Firestore to update an array property. What you're doing is passing an element of an array. The remove(at:) method, when used like this:
let removedElement = someArray.remove(at: someIndex)
will remove the element but return the value of that removed element; it doesn't return the updated array. You must first remove the element and then get the truncated array:
someArray.remove(at: someIndex)
let updated = someArray
Therefore, first remove, then update:
data[0].upvotes!.remove(at: data[0].upvotes!.firstIndex(of: MainView.username ?? "Anonymous")! // first remove
db.collection("forum").document(data[0].id!).setData([
"upvotes": data[0].upvotes!) // then pass
])
However, I'd recommend reformatting the code because it doesn't read very well, IMO, and there is too much force unwrapping for my taste.
I'm using React Native and Open Weather Map API to build a small weather app. The data I retrieve from the API call is more than I want to use so I parse out just the pieces I need and store them in an array. I then take the array and set it to a state object. I can reference the object, but instead of saying my array is an array, it says it's an object, and thus won't let me use any array methods on it. How do I get around this?
//reponseData is the data retrieved from the API call; the data retrieved is an object with arrays and objects
within. The forecast data for the next five days is given in 3 hour increments, so you have a 40 item array of
data pieces. I loop through this list of 40 items, pull out just what I need...
let forecastArray = [];
for (let i=0; i<responseData.list.length; i++) {
let day = responseData.list[i].date
let high = responseData.list[i].weather[0].hiTemp
let low = responseData.list[i].weather[0].loTemp
let condition = responseData.list[i].sys.condition
forecastArray.push(day)
forecastArray.push(high)
forecastArray.push(low)
forecastArray.push(condition)
this.setState({
forecastData: forecastArray
})
When I log, I get an array....
console.warn("forecast is: ", this.state.forecastData)
OUTPUTS: forecast is: ["11-06-2019", 52.5, 47.3, "sunny", "11-06-2019", 63.9, 39.7, "sunny", ...]
Referencing this.state.forecastData[2], for example, however was giving me errors. So I checked the typeof this.state.forecast to see why and it says the array is an Object? I need to further divide out the array data and manipulate it. The first several items (e.x. forecastData[0] through forecastData[9] would be for the forecasted weather for 11-06-2019 at 3pm, ,6pm, 9pm so I need to pull those items, get the highest high and lowest low, etc. I can't do that since I can't even reference the items in the array.
Things I've tried:
using Object.entries and Object.assign methods, but that just splits the items into several arrays, with the first item being the location number and the second item being the array item content. I've tried manipulating the array within the component that uses it, but it still is an Object not an Array, so I can't reference the individual items. The data set is large enough I don't think it would be best practice to push each of the 40+ items into their own state object key.
in Javascript array is a subset of object , i'e it has the same prototype. So typeof Array will be an object. Thats not an issue. Can you update with the error which you are getting while accessing this.state.forecastData[2] coz what i . believe its something not with syntax , rather with the duration of API call.
I would recommend when accessing this.state.forecastData[2] first check if its length is greater than 0 , that way you are sure that there is data inside the array.
constructor(props){
forecastData:[]
}
and when you use it ,
if(this.state.forecastData.length > 0){
this.state.forecastData[2]
}
Try this, and revert with doubts.
Thank you, Gaurav Roy! You were partly correct. The typeof didn't matter at all. But the issue wasn't with the duration of my API, it was that my component was trying to render when it didn't have the data from the API call yet! I put in a conditional
{this.state.forecast !== null && <Forecast forecast=this.state.forecastData />}
and got things working now. Thanks for the quick reply!
Hello everyone I am beginner at react. I want to search i my state which array of object I write the following function for the search. It works perfectly fine to search for the first time.
But when I try to search for the second time it does't work because "tempdata" is now in state. Can anyone please help me to sort?
Here are my code please have a look thanks in Advance.
categorySearch(event){
let tempdata=[];
this.state.data.map((categoryObject,index) => {
if(categoryObject.name.includes(event.target.value)){
tempdata.push(categoryObject);
}
this.setState({data:tempdata});
});
}
I think filter is a better option here instead of map?
Filter returns a new array with all the items that passed the internal conditional - in your case the String includes method.
categorySearch(event){
const filteredElements =
this.state.data.filter(categoryObject => categoryObject.name.includes(event.target.value));
this.setState({filteredElements: filteredElements});
}
Additionally, I suggest keeping your original data unmodified and use a new key in your state filteredElements to store all the search results that match the search query. That way if you want to do a second search, all the original data is still available.
i'm having some problem in updating my array which is global by the way.
here is my code:
Ti.App.dinercolor=["#FF5A00","#007EFF","#dccdc0","#C2FF95","#A700FD","#dccdc0","#dccdc0","#5F9EA0","#dccdc0","#dccdc0","#22A000","#DCCDC0","#dccdc0","#FF003C","#dccdc0","#FF003C","#dccdc0","#22A000","#dccdc0","#FFF191"];
thats my global array which i can access data from it from anywhere in the application.
the problem comes when i want to update the array like:
for(var q=0; q<Ti.App.dinercolor.length; q++){Ti.App.dinercolor[q] = '#dccdc0';}
so, the array i was expecting after the operation thats done is something like this:
Ti.App.dinercolor=["#dccdc0","#dccdc0","#dccdc0","#dccdc0","#dccdc0","#dccdc0","#dccdc0","#dccdc0","#dccdc0","#dccdc0","#dccdc0","#dccdc0","#dccdc0","#dccdc0","#dccdc0","#dccdc0","#dccdc0","#dccdc0","#dccdc0","#dccdc0"];
but somehow i'm getting the same array with out updating,
Ti.App.dinercolor=["#FF5A00","#007EFF","#dccdc0","#C2FF95","#A700FD","#dccdc0","#dccdc0","#5F9EA0","#dccdc0","#dccdc0","#22A000","#DCCDC0","#dccdc0","#FF003C","#dccdc0","#FF003C","#dccdc0","#22A000","#dccdc0","#FFF191"];
please help me out, i have no idea what i'm doing wrong here,
Thank you,,
Your code is correct, but you shouldn't extend the Ti object as unexpected things like this will happen. Create your own object and it will work.
myObj = {};
myObj.dinercolor = [];
And so on.
It is recommended you keep your app in a single context so you will be able to access the object from anywhere. Check out the forging titanium video series for some best practices.
I agree with Jeff, however if you want the above approach to work you will need to update the whole array, you cannot just update elements.
So read the array out into a new variable, update the specific elements and then set the property again
In App.js:
Ti.App.my_variable = 0;
In some_other_page.js:
Ti.App.my_variable = 101;
In yet_another_page.js:
alert( Ti.App.my_variable );
This will alert 101 !!