Find an element from a json file using purrr or rlist

Question

I have a JSON file with very deep hierarchy (e.g. https://raw.githubusercontent.com/APSIMInitiative/ApsimX/master/Models/Resources/Wheat.json)

# read data
library(jsonlite)
m <- read_json('https://raw.githubusercontent.com/APSIMInitiative/ApsimX/master/Models/Resources/Wheat.json')

I would like to find an element with Name == "PotentialBranchingRate".

{
    "$type": "Models.Functions.PhaseLookup, Models",
     "Name": "PotentialBranchingRate",
     "Children": [...]
}

The expected results are to return parental node of "Name": "PotentialBranchingRate".

List of 2
 $ $type: chr "Models.Functions.PhaseLookup, Models"
 $ Name : chr "PotentialBranchingRate"
 $ Children : list ...

I have searched functions in the packages rlist and purrr, but cannot find any ways to do it.

Any suggestions to solve this problem?

Answer 1

library(data.tree)

x <- as.Node(m)

Traverse(x, filterFun = function(.) 
  identical(GetAttribute(., "Name"), "PotentialBranchingRate")
)
#> [[1]]
#>                               levelName
#> 1  2                                   
#> 2   °--Children                        
#> 3       ¦--1                           
#> 4       ¦   °--Children                
#> 5       ¦       °--1                   
#> 6       ¦           °--Children        
#> 7       ¦               °--1           
#> 8       ¦                   ¦--X       
#> 9       ¦                   ¦--Y       
#> 10      ¦                   °--Children
#> 11      °--2                           
#> 12          °--Children                
#> 13              °--1                   
#> 14                  °--Children        
#> 
#> [[2]]
#>              levelName
#> 1 1                   
#> 2  °--Children        
#> 3      °--1           
#> 4          ¦--X       
#> 5          ¦--Y       
#> 6          °--Children

res <- .Last.value
lapply(res, function(.) jsonlite::prettify(rjson::toJSON(as.list(.))))
#> [[1]]
#> {
#>     "$type": "Models.Functions.PhaseLookup, Models",
#>     "Enabled": true,
#>     "IncludeInDocumentation": true,
#>     "Name": "PotentialBranchingRate",
#>     "ReadOnly": false,
#>     "Children": {
#>         "1": {
#>             "$type": "Models.Functions.PhaseLookupValue, Models",
#>             ....
#>        
#> ....... (truncated output for clarity) 
#> 
#> [[2]]
#> {
#>     "$type": "Models.Functions.LinearInterpolationFunction, Models",
#>     "Enabled": true,
#>     "IncludeInDocumentation": true,
#>     "Name": "PotentialBranchingRate",
#>     "ReadOnly": false,
#>     "XProperty": "[Structure].LeafTipsAppeared",
#>     "Children": {
#>         "1": {
#>             "$type": "Models.Functions.XYPairs, Models",
#>             "Enabled": true,
#>             "IncludeInDocumentation": true,
#>             "Name": "XYPairs",
#>             "ReadOnly": false,
#>             "X": {
#>                 "1": 1,
#>                 "2": 2,
#>                 "3": 3,
#>                 "4": 4,
#>                 "5": 5,
#>                 "6": 6,
#>                 "7": 7,
#>                 "8": 8
#>             },
#>             "Y": {
#>                 "1": 0,
#>                 "2": 0,
#>                 "3": 1,
#>                 "4": 2,
#>                 "5": 4,
#>                 "6": 7,
#>                 "7": 12,
#>                 "8": 20
#>             },
#>             "Children": [
#> 
#>             ]
#>         }
#>     }
#> }
#> 

^{Created on 2019-02-21 by the reprex package (v0.2.1)}