Jump to content

Unflatten from JSON and variant to data


Recommended Posts

Hi,

I'm receiving a JSON string from a web API, which I'm trying to convert into a cluster (of clusters) but I've run into some problems:

1) Sometimes the order of the elements in the JSON string changes, which causes my conversion to fail.

2) Sometimes the "object" returned via JSON is null, which causes my conversion to fail if I use clusters within clusters. It works with variants in clusters but then I need to convert the all the variants manually

Is there any way to improve my code to fix those problems? The attached snippet is a simplified version. In my project, the first JSON string to data is done in a library. The second conversion from "result" variant to data is done in my application. This makes a direct conversion from JSON string more difficult.

snip2.png

Link to post
Share on other sites
35 minutes ago, ThomasGutzler said:

1) Sometimes the order of the elements in the JSON string changes, which causes my conversion to fail.

2) Sometimes the "object" returned via JSON is null, which causes my conversion to fail if I use clusters within clusters. It works with variants in clusters but then I need to convert the all the variants manually

To solve both issues, insert "Adapt to Type.vi" before "Variant to Data". However, your cluster element names are now case-sensitive. "TimeStamp" will not match "timeStamp" in the JSON string.

  • Like 1
Link to post
Share on other sites
1 hour ago, smithd said:

Drjdpowell's json library has functionality for breaking subclusters apart and all sorts of other useful ways of manipulating the json strings directly. If you can use 2017 its worth a look.

Unfortunately, I'm still stuck in 2016 land.

But JKSH's suggestion got me going. Thanks

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Similar Content

    • By drjdpowell
      View File JSONtext
      Package for working with JSON.  Uses high-speed text parsing, rather than building an intermediate representation as with prior LabVIEW JSON libraries (this is much faster).  Allows easy working with "subitems" in JSON format, or one can convert to/from LabVIEW types.  Uses the new "malleable VIs" of LabVIEW 2017 to convert to any LabVIEW type directly.
      JSON text makes use of a form a JSON Path notation, allowing easy and rapid access to the subitems of interest.
      Requires LabVIEW 2017 and install by VIPM 2017 or later.
      Original conversation about JSONtext.
      On the LabVIEW Tools Network.
      JDP Science Tools group on NI.com.
      Copyright 2017 JDP Science Limited
      Submitter drjdpowell Submitted 08/02/2017 Category General LabVIEW Version 2017 License Type BSD (Most common)  
    • By drjdpowell
      Package for working with JSON.  Uses high-speed text parsing, rather than building an intermediate representation as with prior LabVIEW JSON libraries (this is much faster).  Allows easy working with "subitems" in JSON format, or one can convert to/from LabVIEW types.  Uses the new "malleable VIs" of LabVIEW 2017 to convert to any LabVIEW type directly.
      JSON text makes use of a form a JSON Path notation, allowing easy and rapid access to the subitems of interest.
      Requires LabVIEW 2017 and install by VIPM 2017 or later.
      Original conversation about JSONtext.
      On the LabVIEW Tools Network.
      JDP Science Tools group on NI.com.
      Copyright 2017 JDP Science Limited
    • By drjdpowell
      View File JSON LabVIEW
      JSON is a data interchange format (sometimes compared to XML, but simpler). There are multiple projects to create a JSON package for LabVIEW. This is yet another one motivated by this hijacked conversation originally about a different project to convert JSON into LabVIEW Variants.

      This project uses a set of LVOOP classes to match the recursive structure of JSON, rather than variants. It allows conversation to and from JSON. All functionality is available through two polymorphic VIs: Set and Get. In addition to Get and Set VIs for common data types, one can also convert directly to or from complex clusters via variant-JSON tools.

      Copyright 2012-2016 James David Powell, Shaun Rumbell, Ton Plomp and James McNally.
      [Note: if you are using LabVIEW 2017, please also see the JSONtext library as a an alternative.]
      Submitter drjdpowell Submitted 10/04/2012 Category General LabVIEW Version  
    • By drjdpowell
      JSON is a data interchange format (sometimes compared to XML, but simpler). There are multiple projects to create a JSON package for LabVIEW. This is yet another one motivated by this hijacked conversation originally about a different project to convert JSON into LabVIEW Variants.

      This project uses a set of LVOOP classes to match the recursive structure of JSON, rather than variants. It allows conversation to and from JSON. All functionality is available through two polymorphic VIs: Set and Get. In addition to Get and Set VIs for common data types, one can also convert directly to or from complex clusters via variant-JSON tools.

      Copyright 2012-2016 James David Powell, Shaun Rumbell, Ton Plomp and James McNally.
      [Note: if you are using LabVIEW 2017, please also see the JSONtext library as a an alternative.]
    • By Pavanb
      Hi There 
      I want to go from TestStand's output i.e. database to HTML5 SPC charts. Sorta like http://moderndata.plot.ly/using-plotly-from-labview-via-python/ Has anyone done this or used Bokeh or Enthough's data tool before?  What about these tools with TDMS or HDF5?
      Thanks. I appreciate it.
      Best,
      Pavan 
      By the way, https://www.enthought.com/services/consulting/case-studies/TAIPAN/ (like TestStand without TestStand)
       
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.