The storage adapter specification for WeChat component application.

Since we need to temporarily storage some key data(e.g. access_token/component_access_token) for invoking WeChat APIs, this module is used for customizing the persistence when use elixir_wechat in the centralization nodes(hereinafter "hub") side of WeChat component application.

Notice: the scenario as a hub, we need to implement the completed functions to maintain the persistence.

writing-custom-storage-adapter

Writing custom storage adapter

Example for WeChat 3rd-party Platform application

defmodule MyComponentAppStorageHub do
  @behaviour WeChat.Storage.ComponentHub

  @impl true
  def fetch_access_token(appid, authorizer_appid, args) do
    access_token = "Get authorizer's access_token for WeChat component application from your persistence..."
    {:ok, %WeChat.Token{access_token: access_token}}
  end

  @impl true
  def fetch_component_access_token(appid, args) do
    access_token = "Get component access_token for WeChat component application from your persistence..."
    {:ok, %WeChat.Token{access_token: access_token}}
  end

  @impl true
  def fetch_component_verify_ticket(appid, args) do
    component_verify_ticket = "Get component_verify_ticket for WeChat component application from your persistence..."
    {:ok, component_verify_ticket}
  end

  @impl true
  def fetch_secret_key(appid, args) do
    secret_key = "Get component application secret_key from your persistence..."
    secret_key
  end

  @impl true
  def fetch_ticket(appid, authorizer_appid, type, args) do
    ticket = "Get authorizer account's ticket for WeChat component application from your persistence..."
    {:ok, ticket}
  end

  @impl true
  def refresh_access_token(appid, authorizer_appid, access_token, args) do
    access_token = "Refresh authorizer's access_token for WeChat component application from your persistence..."
    {:ok, %WeChat.Token{access_token: access_token}}
  end

  @impl true
  def refresh_component_access_token(appid, component_access_token, args) do
    access_token = "Refresh access_token of WeChat component application..."
    {:ok, %WeChat.Token{access_token: access_token}}
  end

  @impl true
  def save_access_token(appid, authorizer_appid, access_token, refresh_token, args) do
    # Save authorizer's access_token and its refresh_token to your persistence
  end

  @impl true
  def save_component_access_token(appid, component_access_token, args) do
    # Save access_token of WeChat component application
  end

  @impl true
  def save_component_verify_ticket(appid, component_verify_ticket, args) do
    # Save component_verify_ticket to your persistence
  end

  @impl true
  def save_ticket(appid, authorizer_appid, ticket, type, args) do
    # Save authorizer account's ticket to your persistence
  end
end

Use MyComponentAppStorageHub

Global configure MyComponentAppStorageHub

defmodule Client do
  use WeChat,
    adapter_storage: {MyComponentAppStorageHub, args}
end

defmodule Client do
  use WeChat,
    adapter_storage: MyComponentAppStorageHub
end

Dynamically set MyComponentAppStorageHub when call WeChat.request/2

WeChat.request(:post, url: ..., adapter_storage: {MyComponentAppStorageHub, args}, ...)
WeChat.request(:post, url: ..., adapter_storage: MyComponentAppStorageHub, ...)

Notice: The above args will be returned back into each implement of callback function, if not input it, args will be as an empty list in callback.