Invoke method to remove a key-value pair in json gives error

Help Studio
1

There is probably silly but I am trying to remove a value in json. I have a json object and want to remove a line.
I am trying to use Invoke method,
TargetObject: blahjson
Method: Remove

param - in -string - “remove this”

I get “object does not have public instance” err

2

Hi @Nick101

Could you maybe provide a dummy sample of the JSON and a screenshot of how you configured your Invoke Method activity?

3

it’s not the json giving err, it is saying the jObject does not have a public instance method named Remove matching the parameter types, generic type arguments, …

4

if your JSON data is in string format, first convert it to a JObject using JObject.Parse(jsonString)

5

image
image278×149 3.47 KB

The image shows a UiPath workflow with an "Invoke Method" activity aimed to call the "Remove" method on a target object named "outblah" and includes a parameter of type string with the value "isDirty". (Captioned by AI)
The image shows a UiPath workflow with an "Invoke Method" activity aimed to call the "Remove" method on a target object named "outblah" and includes a parameter of type string with the value "isDirty". (Captioned by AI)724×422 13.5 KB

6

I gave it a try and it worked:

Some ideas:

  • make sure the Imports panel has the corresponding namespaces added:
    Newtonsoft.Json
Newtonsoft.Json.Linq
  • make sure to update your System activity package

If these two simple fixes don’t work, it would help if you share your Studio and System package versions :slight_smile:

7

The image shows a sequence of activities in a workflow, where an Assign activity assigns a parsed JSON object to a variable, followed by an Invoke Method activity to remove an element from the JSON object. (Captioned by AI)
The image shows a sequence of activities in a workflow, where an Assign activity assigns a parsed JSON object to a variable, followed by an Invoke Method activity to remove an element from the JSON object. (Captioned by AI)467×310 8.69 KB

8

weird, I have all the requiremets

The image shows a workflow with an "Invoke Method" activity in a software development environment, where the variable "outblah" of type JObject is being used, with its details listed below. (Captioned by AI)
The image shows a workflow with an "Invoke Method" activity in a software development environment, where the variable "outblah" of type JObject is being used, with its details listed below. (Captioned by AI)1060×452 19.6 KB

The image shows a list of imported namespaces in a software development environment, including Newtonsoft.Json, Newtonsoft.Json.Linq, System, and others. (Captioned by AI)
The image shows a list of imported namespaces in a software development environment, including Newtonsoft.Json, Newtonsoft.Json.Linq, System, and others. (Captioned by AI)501×232 4.61 KB

9

This will be a stretch, but…
I reproduced your issue by adding an extra space at the beginning of the Method Name:


It also breaks when you add it at the end.

2 Likes
10

Indeed that was the case!

1 Like
11

Stuck again, now I am trying to remove a key value from nested json
I can print it out using this write
outblah(“Towel”)(0)(“IsDirty”).ToString
I tried to make the target object as outblah(“Towel”)(0) and pass the params as (“IsDirty”)
I am getting this msg jtoken does not have a public instance named Remove
Tried all variations, like Target to be outblah and params to be towel as string and IsDirty as Jobject, still get err

12

Convert the JToken to JObject
towelObj = CType(outblah(“Towel”)(0), JObject)
outblah(“Towel”)(0) = towelObj.Property(“IsDirty”).Remove()

13

Thanks, that was the solution

1 Like
14

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