district-ui-web3-chain

Clojurescript re-mount module, that handles the web3 chain the user wallet is connected to.

Installation

Add into your project.clj Include [district.ui.web3-chain] in your CLJS file, where you use mount/start

API Overview

Warning: district0x modules are still in early stages, therefore API can change in a future.

• district.ui.web3-chain
• district.ui.web3-chain.subs
  • ::chain
  • ::has-chain?
• district.ui.web3-chain.events
  • ::load-chain
  • ::set-chain
  • ::poll-chain
  • ::load-chain
  • ::chain-changed
• district.ui.web3-chain.queries
  • chain
  • has-chain?
  • assoc-chain

district.ui.web3-chain

This namespace contains web3-chain mount module. Once you start mount it'll take care of loading web3 chain.

You can pass following args to initiate this module:

• :disable-loading-at-start? Pass true if you don't want load chain at start
• :disable-polling? Pass true if you want to disable polling for chain changes (needed for MetaMask account switching)
• :polling-interval-ms How often should poll for chain changes. Default: 4000
• :load-injected-chain-only? Pass true if you want to load chain only when web3 is injected into a browser

  (ns my-district.core
    (:require [mount.core :as mount]
              [district.ui.web3-chain]))

  (-> (mount/with-args
        {:web3 {:url "https://mainnet.infura.io/"}
         :web3-chain {:polling-interval-ms 5000}})
    (mount/start))

district.ui.web3-chain.subs

re-frame subscriptions provided by this module:

::chain

Returns chain.

::has-chain?

Returns true if user is connected to a chain.

(ns my-district.home-page
  (:require [district.ui.web3-chain.subs :as chain-subs]
            [re-frame.core :refer [subscribe]]))

(defn home-page []
  (let [chain (subscribe [::chain-subs/chain])]
    (fn []
      (if @chain
        [:div "Your active chain is " @chain]
        [:div "You don't have any active chain"]))))

district.ui.web3-chain.events

re-frame events provided by this module:

::load-chain [opts]

Loads web3 chain

::set-chain [chain-id]

Sets chain into db

::poll-chain [opts]

Event fired when polling for chain changes in an interval. Note, polling is used only as fallback option, since MetaMask provides callback registration for chain changed event).

::chain-changed

Fired when chain have been changed. Use this event to hook into event flow from your modules. One example using re-frame-forward-events-fx may look like this:

(ns my-district.events
    (:require [district.ui.web3-chain.events :as chain-events]
              [re-frame.core :refer [reg-event-fx]]
              [day8.re-frame.forward-events-fx]))

(reg-event-fx
  ::my-event
  (fn []
    {:register :my-forwarder
     :events #{::chain-events/chain-changed}
     :dispatch-to [::do-something]}))

::request-switch-chain [chain-id & chain-info]

Makes a RPC request to trigger a chain switch in the connected wallet. If chain id is unknown and chain-info is provided, it will trigger ::request-add-chain event

::request-add-chain [chain-info]

Makes a RPC request to trigger adding a new chain to the connected wallet.

district.ui.web3-chain.queries

DB queries provided by this module: You should use them in your events, instead of trying to get this module's data directly with get-in into re-frame db.

chain [db]

Returns chain

(ns my-district.events
    (:require [district.ui.web3-chain.queries :as chain-queries]
              [re-frame.core :refer [reg-event-fx]]))

(reg-event-fx
  ::my-event
  (fn [{:keys [:db]}]
    (if (empty? (chain-queries/chain db))
      {:dispatch [::do-something]}
      {:dispatch [::do-other-thing]})))

has-chain? [db]

Returns true if user is connected to chain.

assoc-chain [db chain]

Associates chain and returns new re-frame db.

Dependency on other district UI modules

• district-ui-web3
• district-ui-window-focus

Development

lein deps

# To run tests and rerun on changes
lein doo chrome tests