{#
SPDX-License-Identifier: GPL-3.0-or-later OR CC-BY-SA-4.0

Documentation page describing the concept of packages in Haketilo.

This file is part of Hydrilla&Haketilo.

Copyright (C) 2022 Wojtek Kosior

Dual licensed under
* GNU General Public License v3.0 or later and
* Creative Commons Attribution Share Alike 4.0 International.

You can choose to use either of these licenses or both.


I, Wojtek Kosior, thereby promise not to sue for violation of this
file's licenses. Although I request that you do not make use of this
code in a proprietary work, I am not going to enforce this in court.
#}
{% extends "doc_base.html.jinja" %}

{% block title %} Packages {% endblock %}

{% block main %}
  {{ big_heading('Packages in Haketilo') }}

  {% call section() %}
    {% call paragraph() %}
      Users can modify web pages by creating, installing and enabling
      <span class="bold">packages</span>.
      A package associates {{ doc_page_link('URL patterns', 'url_patterns') }}
      with payloads (i.e.  sets of scripts) that can be injected to pages.
      For instance, if an enabled package associates pattern
      <code>https://example.com/***</code> with a script that adds a big
      "Hello world!" text to the page, this package shall cause "Hello world!"
      to appear on pages under <code>example.com</code>.
    {% endcall %}
  {% endcall %}

  {% call section() %}
    {{ medium_heading('Packages and libraries') }}

    {% call paragraph() %}
      To make mapping custom JavaScript applications and their dependencies to
      web pages more manageable, Haketilo defines its own concept of "packages"
      and "libraries".
    {% endcall %}

    {% call unordered_list() %}
      {% call list_entry() %}
        package - Also called <span class="bold">mapping</span>.
        It associates URL patterns with libraries.
      {% endcall %}
      {% call list_entry() %}
        library - Sometimes also referred to as
        <span class="bold">resource</span>.
        Defines a set of scripts that can be injected together into a page.
        It can also name other libraries as its dependencies.
        When injecting scripts of a given library into some page, Haketilo will
        first inject scripts of all libraries depended on.
      {% endcall %}
    {% endcall %}

    {% call paragraph() %}
      It's ultimately a package that provides concrete functionality to the end
      user and that can be enabled or disabled.
      For this reason, a casual user does not even need to be aware of the
      existence of libraries.
      Haketilo UI advanced interface features need to be enabled on the
      {{ hkt_link('settings page', 'home.home') }} for installed libraries to be
      viewable.
    {% endcall %}
  {% endcall %}

  {% call section() %}
    {{ medium_heading('Installing') }}

    {% call paragraph() %}
      Useful packages prepared by others can be installed from Hydrilla
      repositories. The repositories can be configured
      {{ hkt_link('through Haketilo user interface', 'repos.repos') }} as
      described on
      {{ doc_page_link('the relevant documentation page', 'repositories') }}.
      As of Haketilo 3.0-beta1 they need to be manually "refreshed" for new
      packages from them to be shown in Haketilo.
      Available packages viewable on the
      {{ hkt_link('packages listing page', 'items.packages') }} are not
      immediately installed.
      This only happens after they are explicitly enabled or automatically
      enabled (if the user configured Haketilo to do this).
    {% endcall %}

    {% call paragraph() %}
      For convenience, users can also create simple packages
      {{ hkt_link('directly in Haketilo UI', 'import.items_import') }}.
      A simple form can be used to quickly define a standalone script payload
      for a set of URL patterns. As of Haketilo 3.0 only simple (i.e.
      single-library) payloads can be created this way.
    {% endcall %}

    {% call paragraph() %}
      It is also possible to import packages from files.
      For this, a directory of serveable mappings and reasources - as produced
      by Hydrilla builder and used by Hydrilla server - has to be put into a ZIP
      archive.
      It can then be uploaded to Haketilo via its
      {{ hkt_link('import page', 'import.items_import') }}.
    {% endcall %}
  {% endcall %}

  {% call section() %}
    {{ medium_heading('Uninstalling') }}

    {% call paragraph() %}
      Haketilo tracks dependencies between packages and libraries and
      automatically determines which of them are no longer needed.
      These are called <span class="bold">orphans</span> and if present, can be
      removed from the {{ hkt_link('settings page', 'home.home') }}.
      A version of package or library that is not being used but is still
      available from an active repository is not considered an orphan. It
      automatically becomes one when the repository either stops advertising it
      as available or gets removed by the user from
      {{ hkt_link('the repositories list', 'repos.repos') }}.
    {% endcall %}

    {% call paragraph() %}
      When advanced UI features are enabled, it is additionally possible to
      manually uninstall any single package that is not in use at a given
      moment.
    {% endcall %}
  {% endcall %}

  {% call section() %}
    {{ medium_heading('Package contents') }}

    {% call paragraph() %}
      Each package has an <span class="bold">identifier</span> (built from a
      restricted set of characters), a <span class="bold">long name</span>, a
      <span class="bold">description</span>, a <span class="bold">version</span>
      and almost always a list of <span class="bold">license files</span> and a
      set of <span class="bold">URL patterns mapped to libraries</span>.
      In addition there might also be other pieces of information such as
      required permissions.
    {% endcall %}
  {% endcall %}

  {% call section() %}
    {{ medium_heading('Enabling/disabling') }}

    {% call paragraph() %}
      The user can put package in any of 3 possible states.
      It can be either <span class="bold">enabled</span>,
      <span class="bold">disabled</span> or
      <span class="bold">not configured</span>.
    {% endcall %}

    {% call paragraph() %}
      An enabled package always has its payloads injected on pages matched by
      their patterns (unless some more specific pattern takes precedence on the
      given page as described on the
      {{ doc_page_link('policy selection page', 'policy_selection') }}).
    {% endcall %}

    {% call paragraph() %}
      A disabled package is always ignored.
      It has to be manually re-enabled for Haketilo to take it into account
      again.
    {% endcall %}

    {% call paragraph() %}
      Finally, a package that is neither explicitly enabled nor disabled can be
      treated differently depending on user's choice on the
      {{ hkt_link('settings page', 'home.home') }}.
      It is possible to have Haketilo
    {% endcall %}

    {% call unordered_list() %}
      {% call list_entry() %}
        automatically inject such packages' payloads on mathing pages,
      {% endcall %}
      {% call list_entry() %}
        prompt the user on matching pages asking whether the package should be
        enabled or
      {% endcall %}
      {% call list_entry() %}
        completely ignore non-configured packages.
      {% endcall %}
    {% endcall %}
  {% endcall %}

  {% call section() %}
    {{ medium_heading('Handling multiple versions') }}

    {% call paragraph() %}
      It is possible to have many versions of the same package or library
      installed.
      When this is the case, Haketilo by default uses the newest versions it
      can.
      Additionally, if certain package is enabled, its page also allows the user
      to configure its <span class="bold">pinning</span>.
      A package can be
    {% endcall %}

    {% call unordered_list() %}
      {% call list_entry() %}
        pinned to use a particular version,
      {% endcall %}
      {% call list_entry() %}
        pinned to use the best version from a particular
        {{ doc_page_link('repository', 'repositories') }} or
      {% endcall %}
      {% call list_entry() %}
        not pinned at all (best version overall is used).
      {% endcall %}
    {% endcall %}
  {% endcall %}
{% endblock main %}