Powershell append to an existing object breaks the format of json

Question

Trying to append an array to a json object but having formatting issues. after appending the desired output format is not a json or as expected.

i have a json object, then converted a json object to custom nested object then trying to append new objects to array which is where am getting formatting issues.

help on this is really appreciated.

below is code

$json = @'
{
  "scope": {
    "entities": [],
    "matches": [
      {
        "type": null,
        "managementZoneId": null,
        "mzId": null,
        "tags": [
          {
            "context": "CONTEXTLESS",
            "key": "DetectedName",
            "value": ""
          }
        ],
        "tagCombination": "AND"
      }
    ]
  }
}
'@

# Convert from JSON to a nested custom object.
$obj = $json | ConvertFrom-Json

# Append new objects to the array.
$obj.scope.matches += [pscustomobject] @{ type = 'null'
                                          managementZoneId = 'null'
                                          mzId = 'null' 
                                          tags = '[{ "context": "CONTEXTLESS", "key": "DetectedName", "value": "naae22let1ci1.ktb.kontoorbrands.com" }]'
                                            tagCombination = 'AND' }

# Convert back to JSON.
$obj | ConvertTo-Json -Depth 100"

output is:

{
  "scope": {
    "entities": [],
    "matches": [
      {
        "type": null,
        "managementZoneId": null,
        "mzId": null,
        "tags": [
          {
            "context": "CONTEXTLESS",
            "key": "DetectedName",
            "value": ""
          }
        ],
        "tagCombination": "AND"
      }
      {
                                      "type":  "null",
                                      "managementZoneId":  "null",
                                      "mzId":  "null",
                                      "tags":  "[{ \"context\": \"CONTEXTLESS\", \"key\": \"DetectedName\", \"value\": \"naae22let1ci1.ktb.kontoorbrands.com\" }]",
                                      "tagCombination":  "AND"
                                  }
    ]
  }
}

desired output :

$obj | ConvertTo-Json -Depth 100
{
    "scope":  {
                  "entities":  [

                               ],
                  "matches":  [
                                  {
                                      "type":  null,
                                      "managementZoneId":  null,
                                      "mzId":  null,
                                      "tags":  [
                                                   {
                                                       "context":  "CONTEXTLESS",
                                                       "key":  "DetectedName",
                                                       "value":  ""
                                                   }
                                               ],
                                      "tagCombination":  "AND"
                                  },
                                  {
                                      "type":  null,
                                      "managementZoneId":  null,
                                      "mzId":  null,
                                      "tags":  [
                                                   {
                                                       "context":  "CONTEXTLESS",
                                                       "key":  "DetectedName",
                                                       "value":  ""
                                                   }
                                               ],
                                      "tagCombination":  "AND"
                                  }
                              ]
              }
}

I think someone wrote a nice function to format JSON files on PowerShell, it should be here on SO, can't recall the link right now. — Santiago Squarzon, Jul 07 '21 at 18:16

score 2 · Accepted Answer · answered Jul 07 '21 at 18:41

As you are converting the json to an object, you need to add the new items as objects too, not as json strings.

Try

$json = @'
{
  "scope": {
    "entities": [],
    "matches": [
      {
        "type": null,
        "managementZoneId": null,
        "mzId": null,
        "tags": [
          {
            "context": "CONTEXTLESS",
            "key": "DetectedName",
            "value": ""
          }
        ],
        "tagCombination": "AND"
      }
    ]
  }
}
'@

# Convert from JSON to a nested custom object.
$obj = $json | ConvertFrom-Json

# Append new objects to the array.
$obj.scope.matches += [PsCustomObject]@{ 
    type             = $null
    managementZoneId = $null
    mzId             = $null
    # the next element is an array of PsCustomObjects, hence the need for @()
    tags             = @([PsCustomObject]@{
                            context = "CONTEXTLESS"
                            key     = "DetectedName"
                            value   = "naae22let1ci1.ktb.kontoorbrands.com"
                       })
    tagCombination   = 'AND'
}

# Convert back to JSON.
$obj | ConvertTo-Json -Depth 100

Output:

{
    "scope":  {
                  "entities":  [

                               ],
                  "matches":  [
                                  {
                                      "type":  null,
                                      "managementZoneId":  null,
                                      "mzId":  null,
                                      "tags":  [
                                                   {
                                                       "context":  "CONTEXTLESS",
                                                       "key":  "DetectedName",
                                                       "value":  ""
                                                   }
                                               ],
                                      "tagCombination":  "AND"
                                  },
                                  {
                                      "type":  null,
                                      "managementZoneId":  null,
                                      "mzId":  null,
                                      "tags":  [
                                                   {
                                                       "context":  "CONTEXTLESS",
                                                       "key":  "DetectedName",
                                                       "value":  "naae22let1ci1.ktb.kontoorbrands.com"
                                                   }
                                               ],
                                      "tagCombination":  "AND"
                                  }
                              ]
              }
}

^{P.S. PowerShell does not produce 'pretty' json. If you need to convert it to properly spaced json, see my function Format-Json}

Thanku Theo, helpful answer with nice explanation.. – Ram Jul 07 '21 at 19:28 — Ram, Jul 07 '21 at 19:28

Powershell append to an existing object breaks the format of json

1 Answers1