I'm using scala play and am attempting to traverse a json tree in order to validate that specific name values have specific children with specific name values. I have the following Json in the form of a JsObject:
{ "name": "user", "children": [ { "name": "$a", "children": [ { "name": "foo", "children": [ ] }, { "name": "fooBar", "children": [ { "name": "$a", "children": [ { "name": "subFoobar1", "children": [ ] }, { "name": "subFoobar2", "children": [ { "name": "TEST", "children": [ ] } ] }, { "name": "subFoobar3", "children": [ ] } ] } ] }, { "name": "bar", "children": [ { "name": "$a", "children": [ ] }, { "name": "$c", "children": [ ] }, { "name": "$b", "children": [ ] } ] }, { "name": "barFoo", "children": [ ] } ] } ] }
Ideally I would use nested for loops to traverse but the JsObject structure is preventing me from accessing the underlying values when attempting traverse. I have also attempted mapping the JsObject to a map of type [Map[String,Map[String,Any]]] but I am getting invalid cast compiler errors.
Any tips on how I can traverse and validate the name value at each level would be appreciated. I would preferably like to use the play json library
Issue was in the case class I was attempting to use. I wasn't accounting for the recursive nature of my Json structure
case class ActorTree(name : String, children:Seq[ActorTree] )
Related
I have a requirement to roll a collection of nodes that uses the current node name (within the collection) and for the value take each child nodes value (single node) into a string array, then use the parents key as the key.
Given.
{
"client": {
"addresses": [
{
"id": "27ef465ef60d2705",
"type": "RegisteredOfficeAddress"
},
{
"id": "b7affb035be3f984",
"type": "PlaceOfBusiness"
},
{
"id": "a8a3bef166141206",
"type": "EmailAddress"
}
],
"links": [
{
"id": "29a9de859e70799e",
"type": "Director",
"name": "Bob the Builder"
},
{
"id": "22493ad4c4fd8ac5",
"type": "Secretary",
"name": "Jennifer"
}
],
"Names": [
{
"id": "53977967eadfffcd",
"type": "EntityName",
"name": "Banjo"
}
]
}
}
from this the output needs to be
{
"client": {
"addresses": [
"RegisteredOfficeAddress",
"PlaceOfBusiness",
"EmailAddress"
],
"links": [
"Director",
"Secretary"
],
"Names": [
"EntityName"
]
}
}
What is the best way to achieve this? Any pointers to what/how to do this would be greatly appreciated.
Ron.
You can iterate over entries of your client object first with the help of the $each function, then get types for each of them, and combine via $merge:
{
"client": client
~> $each(function($list, $key) {{ $key: $list.type }})
~> $merge
}
Live playground: https://stedi.link/OpuRdE9
I'm trying to prune nodes deeply within a JSON structure and I'm puzzled why empty behaves seemingly different from a normal value here.
Input
[
{
"name": "foo",
"children": [{
"name": "foo.0",
"color": "red"
}]
},
{
"name": "bar",
"children": [{
"name": "bar.0",
"color": "green"
},
{
"name": "bar.1"
}]
},
{
"name": "baz",
"children": [{
"name": "baz.0"
},
{
"name": "baz.1"
}]
}
]
Program
jq '(.[].children|.[])|=if has("color") then . else empty end' foo.json
Actual output
[
{
"name": "foo",
"children": [
{
"name": "foo.0",
"color": "red"
}
]
},
{
"name": "bar",
"children": [
{
"name": "bar.0",
"color": "green"
}
]
},
{
"name": "baz",
"children": [
{
"name": "baz.1"
}
]
}
]
Expected output
The output I get, except without the baz.1 child, as that one doesn't have a color.
Question
Apart from the right solution, I'm also curious why replacing empty in the script by a regular value like 42 would replace the children without colors with 42 as expected, but when replacing with empty, it looks like the else branch doesn't get executed?
.[].children |= map(select(.color))
Will remove children that does not has an color so the output becomes:
[
{
"name": "foo",
"children": [
{
"name": "foo.0",
"color": "red"
}
]
},
{
"name": "bar",
"children": [
{
"name": "bar.0",
"color": "green"
}
]
},
{
"name": "baz",
"children": []
}
]
Online demo
Regarding why your filter does not seem to like empty;
This git issue seems to be the cause, multiple elements with empty will fail.
There must be a bug with assigning empty to multiple paths.
In this case you can use del instead:
del(.[].children[] | select(has("color") | not))
Online demo
I am going to write json schema to verify tree data.
Schema consisting of top root and block below.
There may be another block below the block.
Schema for validation.
schema = {
"$schema": "http://json-schema.org/draft-04/schema",
"$ref": "#/definitions/root",
"definitions":{
"root": {
"properties": {
"name": {
"type": "string"
},
"children": {
"type": "array",
"items": [
{"$ref":"#/definitions/block"}
]
}
},
"required": ["name", "children"]
},
"block": {
"properties": {
"name": {
"type": "string"
},
"children": {
"type": "array",
"items": [
{"$ref":"#/definitions/block"}
]
}
},
"required": ["name"]
}
}
}
Below is incorrect data for testing. The last name properties do not exist.
{
"name": "group8",
"children": [
{
"name": "group7",
"children": [
{
"name": "group6",
"children": [
{
"name": "group5",
"children": [
{ ###### wrong
"children": []
}
]
}
]
}
]
}
]
}
This data validates well, but it doesn't work on a slightly complex tree.
# Error: ValidationError: file /home/gulliver/.local/lib/python2.7/site-packages/jsonschema/validators.py line 934: 'name' is a required property #
{
"name": "group8",
"children": [
{
"name": "group7",
"children": [
{
"name": "group6",
"children": [
{
"name": "group12",
"children": [
{
"name": "group11",
"children": [
{
"name": "group10",
"children": []
}
]
}
]
},
{
"name": "group9",
"children": [
{
"name": "group5",
"children": [
{ ####### wrong
"children": []
}
]
}
]
}
]
}
]
},
{
"name": "group13",
"children": [
{
"name": "null1",
"children": []
}
]
}
]
}
It does not work when the data at the bottom of the tree is invalid.
My guess is that the branch splits and this happens, does anyone know why or how to fix it?
I tested using python and jsonschema.
When items is an array, it applies the subschema values to the same index location in the array in the instance.
For example, where you define...
"items": [
{"$ref":"#/definitions/block"}
]
only the first item in the array will be tested. It has nothing to do with deep nesting. For example, the follwing data is valid according to your schema...
{
"name": "group8",
"children": [
{
"name": "group7"
},
{
"something": "else",
"Not": "name"
}
]
}
(Live demo: https://jsonschema.dev/s/etFGE)
If you modify your use of items, then it will work like you expect:
"items": {"$ref":"#/definitions/block"}
(do this for both uses)
Live demo: https://jsonschema.dev/s/rk1OD
I have a single table in database like database table. I want to search a child from database and return a hierarchical JSON to a front end in order to create a tree. How can I do that in FLASK.
My expected JSON for mat should be like expected JSON
Since you have tagged your question with flask, this post assumes you are using Python as well. To format your database values in JSON string, you can query the db and then use recursion:
import sqlite3, collections
d = list(sqlite3.connect('file.db').cursor().execute("select * from values"))
def get_tree(vals):
_d = collections.defaultdict(list)
for a, *b in vals:
_d[a].append(b)
return [{'name':a, **({} if not (c:=list(filter(None, b))) else {'children':get_tree(b)})} for a, b in _d.items()]
import json
print(json.dumps(get_tree(d), indent=4))
Output:
[
{
"name": "AA",
"children": [
{
"name": "BB",
"children": [
{
"name": "EE",
"children": [
{
"name": "JJ",
"children": [
{
"name": "EEV"
},
{
"name": "FFW"
}
]
},
{
"name": "KK",
"children": [
{
"name": "HHX"
}
]
}
]
}
]
},
{
"name": "CC",
"children": [
{
"name": "FF",
"children": [
{
"name": "LL",
"children": [
{
"name": "QQY"
}
]
},
{
"name": "MM",
"children": [
{
"name": "RRV"
}
]
}
]
},
{
"name": "GG",
"children": [
{
"name": "NN",
"children": [
{
"name": "SSW"
}
]
}
]
}
]
},
{
"name": "DD",
"children": [
{
"name": "HH",
"children": [
{
"name": "OO",
"children": [
{
"name": "TTZ"
}
]
}
]
},
{
"name": "II",
"children": [
{
"name": "PP",
"children": [
{
"name": "UUW"
}
]
}
]
}
]
}
]
}
]
I'm working on json Data with inner childrens. i need to get all the name's in the json.
json data
this.res = [
{
"children": [
{
"children": [
{
"children": [],
"name": "P Sub Child 3",
},
{
"children": [
{
"children":[],
"name" : "data"
}
],
"name": "PSubChild2",
}
],
"name": "PChild1",
},
{
"children": [
{
"children": [],
"name": "PSubChild3",
}
],
"name": "PChild2",
}
],
"name": "Parent1",
},
{
"children": [],
"name": "Parent2",
}
];
in my application names of every child has to store in the variables using angular2.
Data is dynamic changes as per the user in my application
From what I understand you want to just get the value of the name property down the hierarchical data you have then as most here suggested you have to use recursion to get to the name property. With Rxjs it becomes a bit easier to do like following:
Observable.from(this.res)
.expand(d => d.children.length > 0 ? Observable.from(d.children) : Observable.empty())
.subscribe(d => console.log(d.name));
I have made a working sample here: https://jsfiddle.net/ibrahimislam/ba17w8xz/1/
Here is a plunkr of a possible implementation
https://plnkr.co/edit/njM1HLx7vuZY9loto2pM?p=preview
Create your own datatype:
export class MyNode {
children:Array<MyNode>;
name:string;
}
and then create a method to recursively loop your parents to get their names and the names of the children
parents:Array<MyNode> = [
{
"children": [
{
"children": [
{
"children": [],
"name": "P Sub Child 3",
},
{
"children": [
{
"children":[],
"name" : "data"
}
],
"name": "PSubChild2",
}
],
"name": "PChild1",
},
{
"children": [
{
"children": [],
"name": "PSubChild3",
}
],
"name": "PChild2",
}
],
"name": "Parent1",
},
{
"children": [],
"name": "Parent2",
}
];
names:Array<string>=[];
getAllNames(){
this.getNameHelper(this.parents);
}
getNameHelper(parents:Array<MyNode>){
for(var p of parents){
if(p.name){
this.names.push(p.name);
}
if(p.children){
this.getNameHelper(p.children);
}
}
}