Framework's alternative to HasChange()

Terraform Providers Plugin Development
2

Hi @mkuzmin :wave: Welcome to HashiCorp Discuss and thank you for posting this. Apologies that this is not well documented at the moment. I have created Document Resource Update HasChange Equivalent · Issue #527 · hashicorp/terraform-plugin-framework · GitHub to address that issue.

To accomplish something similar in the framework, you can compare the plan and prior state data values from the resource.UpdateRequest type Plan and State fields.

If using a schema data model type:

type ThingResourceModel struct {
  ServiceName types.String `tfsdk:"service_name"`
  // ...
}

// Update logic
var plan, state ThingResourceModel

resp.Diagnostics.Append(req.Plan.Get(ctx, &plan)...)
resp.Diagnostics.Append(req.State.Get(ctx, &state)...)

if resp.Diagnostics.HasError() {
  return
}

if !plan.ServiceName.Equal(state.ServiceName) {
  srv.SetServiceName(plan.ServiceName.ValueString())
}

If working with individual attributes, it is a more verbose as more attributes are compared:

// Update logic
var serviceNamePlan, serviceNameState types.String

resp.Diagnostics.Append(req.Plan.GetAttribute(ctx, path.Root("service_name"), &serviceNamePlan)...)
resp.Diagnostics.Append(req.State.GetAttribute(ctx, path.Root("service_name"), &serviceNameState)...)

if resp.Diagnostics.HasError() {
  return
}

if !serviceNamePlan.Equal(serviceNameState) {
  srv.SetServiceName(serviceNamePlan.ValueString())
}

Hope this helps and please reach out if you have further questions.

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