topic Re: Recreate object from json in Revit API Forum

Recreate object from json

Moustafa_el-sawy — Mon, 14 Nov 2022 16:30:49 GMT

Hi, Im to Revit API but I have been searching regarding this for a while. Is there any functionality in the API to recreate a certain object if you have a json of this object.

For example:
Using the Revit API I can get a selected TextNote as an object. If I serialize this into a Json, am I able to recreate this using the Revit API without hardcoding the api call to recreate this TextNote?

Grasshopper has this functionality where you can recreate objects from a json (https://developer.rhino3d.com/api/RhinoCommon/html/M_Rhino_Runtime_CommonObject_FromJSON_1.htm)

Is there anything similar in Revit API?

Thanks!

Re: Recreate object from json

jeremy_tammik — Mon, 14 Nov 2022 18:06:15 GMT

Welcome to the Revit API.

Yes, sure.

You are talking about serialisation, or, more generally storage in an external (file) format.

<joke>

Please be aware that the BIM is a pretty complex construct full of mutual dependencies. Therefore, it is hardly feasible to store the entire BIM in JSON. For that reason, instead of JSON, Revit uses the file RVT format.

</joke>

A simple object such as a TextNote with relatively few constraints and relationships to other objects can easily be serialised to JSON and recreated via the API from that data. Due to the complexity of the BIM in general, though, the Revit API does not provide a built-in method to serialise objects to JSON or any other text based format. You can create you own, if you like.

Re: Recreate object from json

Moustafa_el-sawy — Mon, 14 Nov 2022 18:28:47 GMT

Hi Jeremy,

Thanks for your quick response. Yes I am aware of the complexity of BIM objects :).

I was planning on limiting the json to object to just 2D elements (in a drafting view) such as AnnotionSymbol, DetailLines, Dimensions,Sketch,TextNotes etc (this what I have so far roughly from exploring the views using Revit Lookup). This means in theory I am able to parse a 2d view, convert all my objects to json and then re-import this json into any revit version/model and re-create this view. Theoretically this is possible right (assuming API calls didnt change much between the versions). I am simplifying it and I am sure will face issues but in terms of API capabilities, this should be doable right?

Thanks!

Re: Recreate object from json

jeremy_tammik — Mon, 14 Nov 2022 21:24:33 GMT

Yes, absolutely doable. Sounds like a great project and absolutely viable. You might run into difficulties, just as you say. Try not to invest effort in fixing them, just try to work around or avoid them. Follow these:

Then, all will be well.

Re: Recreate object from json

Moustafa_el-sawy — Mon, 14 Nov 2022 21:26:08 GMT

haha true. I follow KISS as much as I can. Hope it works out and this would solve the issue of not being able to transfer 2D details backwards in revit versions!