How can I get the id of an object?
In this example I want to get the 'ok' and store it in a variable.
I know how to access the data.I need to access the id and store it for some purpose.
I use Angular so the console log is like this
'console.log (this.Data');'
{ok: Array(2)}
ok: Array(2)
.
.
.
Always depends in your JSON structure but if you want the object inside the 'ok' key you can access through the key, for example:
{
"ok": Array(2)
}
You can access with the key associated at the object:
this.Data.ok;
this.Data[ok];
Ok i find the solution.I changed the object.I set an 'id' and a 'data' field.Now i can access it like this.Data.id and this.Data.data.
You can get every key from your JSON with Object.keys.
Object.keys(this.data)
Related
I can't figure out how to access this output from JSON
p (2 items)
0:"message" -> "ok"
1:"results" -> List (1 item)
key:"results"
value:List (1 item)
[0]:Map (4 items)
0:"uid" -> "1"
1:"name" -> "TallyMini"
2:"camera" -> "2"
3:"Version" -> "0.1.0"
enter code here
lst.add(convertDataToJson[1]['value']['name']);
I have tried various combinations of indexs 'result', 'list', 'value', name
I guess you are using http and get a JSON object from the server. And in this case, call json.decode() method then
Flutter understands JSON as a Map . ( Map<String, dynamic> json).
So, to get the value of name field, firstly you need to access to results field.
json['results'] . It is a list, and continue accessing to the name field.
It my answer is not helpful for you, please show me more your code.
You can try like as:
String name= jsonData['results'][0]['name'];
Please let me know it's work or not.
I have defined a list for operational data in yang model as:
list listener-state {
key “listener-name”;
config false;
description
“common statistics for given listener (i.e sent messages)”;
uses listener-state-info;
…
}
I use opendaylight api (org.opendaylight.yangtools.yang.data.codec.gson.JsonParserStream) which will convert the json body in request to org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode, in order to finally generate the XML rpc for confd server.
In my case, I want to fetch all rows from this operation list, then I try to make the json as :
“command”: {“service” : {“server” : {“listener-state” : {}}}},
I will get exception that : “Input is missing some of the keys of listener-state”
Then I can add the key value to the json body :
“command”: {“service” : {“server” : {“listener-state” : {“listener-name”: “first”}}}},
This case, I can only get one row. I also try to leave the key value as blank:
“command”: {“service” : {“server” : {“listener-state” : {“listener-name”: “”}}}},
Then the response will be all key values instead of all rows. So now my question is what the json will be in order to get all rows in the list without knowing the key values ?
This should be feasible since I figure out XML request can do that. But I can't figure out what the matching json will be.
Thanks.
I did bunch of investigation. Unfortunately, I don't think there is a way to fetch the whole table
function updateFirebase(){
const fb=firebase.database().ref()
//get field values
author = document.getElementById('uname').value
user_email = document.getElementById('umail').value
data = {author, user_email}
//update database
fb.child('Article/').update(data);
}
</script>
I have problem with my code. I want to update the data inside a table named "Article". Article has generated items with a unique key/id and each key has its own content. Lets say I want to be able to edit the "author" or change the "title", the problem is they each have a randomly generated key/id that I cant access. for example that "-LS39kReBHrKGqNj7h_". I can only save the data inside the "Article" tree but I cant change the "author" or the "title". How do i get a workaround this so I can change those properties?
Here is how my firebase looks like
It depends whether you have the record reference on the frontend before update or not (whether you have fetched it before you are trying to update it).
But generally, you have two options
You can store the key reference as an "id" field on the object.
To achieve that, you need two step process when creating the record at the first place
// Creates a new record in DB and returns it to you. Now you can get the "key"
const newRecord = firebase.database().ref('TABLE_NAME_REF').push();
newRecord.set({
id: newRecord.key
...
});
This is great if you fetch the list of records on the frontend and then you want to update one of them. Then you can just build the ref path like this
fb.child('Article/' + record.id ).update(data); // where record is the prefetched thing
You need to find the element based on its fields first. And once you have it, you can update it right away.
To achieve this, you can simply do something like:
firebase.database()
.ref('TABLE_NAME_REF') // let's say 'Article'
.orderByChild('RECORD_KEY') // Let's say 'author'
.equalTo('KEY_VALUE') // let's say 'zoranm'
.limitToFirst(1)
.once("value")
.then(res => {
// You need to loop, it always returns an array
res.forEach(record => {
console.log(record.key); // Here you get access to the "key"
fb.child('Article/' + record.key ).update(data); // This is your code pasted here
})
})
I need value from MySQL send into PLC via OPC UA (in NODE-RED). Everything works ok, but I don't know how to get pure value without descriptions of array etc.
I use this code:
SELECT `user_info` FROM `users` WHERE `user_name` LIKE 'Lukas'
The answer is:
array[1]
0: object
user_info: "6"
If I send it to PLC as STRING the value in PLC is:
[object Object]
Can I edit the code somehow? I need answer only:
6
Thank you
The answer is array[1] 0: object user_info: "6"
I assume you've copied that out of the Debug window which shows you the exact structure of the payload you've received.
That is saying, the payload is an array with a single element. That element is an object with a user_info property of value 6.
In other words:
[
{
"user_info": "6"
}
]
In which case, to access the value you would use:
msg.payload[0].user_info
For example, a Function node to pull that value out and put it into the payload would be:
msg.payload = msg.payload[0].user_info;
return msg;
Or you could use a Change node to set the value of msg.payload to the value of msg.payload[0].user_info.
I have this JSON output
{
"status":1,
"complete":1,
"list":{
"792489954":{
"item_id":"792489954",
"resolved_id":"792489954",
"given_url":"http:\/\/www.liveathos.com\/?gclid=Cj0KEQiAzb-kBRDe49qh9s75m-wBEiQATOxgwZcJ5_ws34o4PUSUYDGqs8HEbLF-LyjxrTPOwn6AYV8aAmMk8P8HAQ",
"given_title":"Athos - Wearable Technology for Fitness",
"favorite":"0",
"status":"0",
"time_added":"1418754744",
"time_updated":"1418754746",
"time_read":"0",
"time_favorited":"0",
"sort_id":0,
"resolved_title":"Wearable Technology for Fitness",
"resolved_url":"http:\/\/www.liveathos.com\/?gclid=Cj0KEQiAzb-kBRDe49qh9s75m-wBEiQATOxgwZcJ5_ws34o4PUSUYDGqs8HEbLF-LyjxrTPOwn6AYV8aAmMk8P8HAQ",
"excerpt":"Thank you for reserving Athos. You will receive a confirmation email with reservation details and a referral link where you get $10 off your next order.",
"is_article":"0",
"is_index":"0",
"has_video":"0",
"has_image":"0",
"word_count":"25"
},
"692647226":{
"item_id":"692647226",
"resolved_id":"692647226",
"given_url":"http:\/\/www.terrafugia.com\/news",
"given_title":"News | Terrafugia",
"favorite":"0",
"status":"0",
"time_added":"1418754204",
"time_updated":"1418754204",
"time_read":"0",
"time_favorited":"0",
"sort_id":1,
"resolved_title":"News",
"resolved_url":"http:\/\/www.terrafugia.com\/news",
"excerpt":"",
"is_article":"0",
"is_index":"1",
"has_video":"0",
"has_image":"0",
"word_count":"0"
},
`...etc` "since":1419641101
};
It's a JSON with a list that should have article items on it. I want to access the properties of these smaller items like given_url.
I'm using
for key in (BIGJSONRESPONSE).list
do etc...
When I try printing the key, I get only the id that comes before an item. Any idea how to access more?
Thanks!
You asked for the keys, you got the keys. To get the item associated with that key, use BIGJSONRESPONSE.list[key].
This should be correct:
for in returns the keys of an object. Since the key refers to a property of the object one can access the property using [key].
for (key in (BIGJSONRESPONSE).list)
{
console.log(BIGJSONRESPONSE.list[key]) // log the entry to console for debugger.
}