Unable to decode req.Body in CallResource function

[ashritha]

Hi,

I am trying to implement a custom HTTP call for variable substitution with type Query in datasource-backend-sdk-go plugin.
Followed the steps mentioned in this article and was able to capture the query input from the Variables page.
I have overridden metricFindQuery method in datasource.ts file and made call to backend using postResource() method.
Here’s how my metricFindQuery and CallResource method looks

async metricFindQuery(query: string, options?: any) {
 const response = await this.postResource('facet-query', { query: query, test: 'val' });
  }

func (d *DataSetDatasource) CallResource(ctx context.Context, req *backend.CallResourceRequest, sender backend.CallResourceResponseSender) error {
        var fm filterModal
	err1 := json.Unmarshal(req.Body, &fm)
}

type filterModal struct {
    query string `json:"query"`
}

So, the issue is, the documentation says req.Body should have the data that has been passed through postResource method. But when I try to access the data, it shows an encoded string in bytes format, and Unmarshall always returns empty.

Any help on this is appreciated

[marcusolsson]

In case anyone drops in from Google, the issue was that the frontend URL-encoded the JSON before sending it to the resource handler, which meant that the json package couldn’t decode the payload.