hc_roles_mixin

Generic holochain mixin to include administrator and dynamic roles in any holochain application, using the progenitor pattern.

This mixin is built to target hc v0.0.42-alpha3. It also depends on the holochain_anchors to be present and configured.

Known issue: due to updated entries not being propagated, this mixin won't actually work in a real environtment, since it depends on an update on the role entry to be propagated througout the network.

Design

Here is the design for this mixin: https://hackmd.io/6xfwfSVYSGeZe3vQ_-1cWw?view.

Documentation

Here you can find the documentation for this mixin: https://docs.rs/hc_roles_mixin.

Installation

Add the following to your zomes cargo toml.

holochain_anchors = "0.2.1"
hc_roles_mixin = "0.1.3"

Usage

Setup

Add the anchor entry definition to your zome.

 #[entry_def]
fn anchor_def() -> ValidatingEntryType {
    holochain_anchors::anchor_definition()
}

Add the roles entry definition to your zome.

 #[entry_def]
fn roles_def() -> ValidatingEntryType {
    hc_roles_mixin::role_entry_def()
}

In your init function, create the Admin role:

#[init]
fn init() {
    hc_roles_mixin::handlers::create_admin_role()?;
    Ok(())
}

Create a role

To create a role, simply call the create_role function:

#[zome_fn("hc_public")]
fn some_public_function() {
    let my_role_name = String::from("editor");

    hc_roles_mixin::handlers::create_role(&my_role_name)?;
    ...
}

Assign a role

To assign a role, simply call the assign_role function:

#[zome_fn("hc_public")]
fn some_other_public_function(agent_address: Address) {
    let my_role_name = String::from("editor");

    hc_roles_mixin::handlers::assign_role(&my_role_name, &agent_address)?;
    ...
}

Check if user has a certain role

To check if a user has a certain role, you can use the validation has_agent_role function:

validation: | _validation_data: hdk::EntryValidationData<MyEntry>| {
    match _validation_data {
        hdk::EntryValidationData::Create { entry, validation_data } => {
            let agent_address = &validation_data.sources()[0];
            let is_agent_permitted_to_create_this_entry = hc_roles_mixin::validaton::has_agent_role(&agent_address, String::from("editor"))?;

            if !is_agent_permitted_to_create_this_entry {
                return Err(String::from("Only editors can create a new entry"));
            }
            ...
            

Unassign a role

To unassign a role, simply call the unassign_role function:

#[zome_fn("hc_public")]
fn some_other_public_function(agent_address: Address) {
    let my_role_name = String::from("editor");

    hc_roles_mixin::handlers::unassign_role(&my_role_name, &agent_address)?;
    ...
}