Tachiyomi-Extensions/CONTRIBUTING.md

Contributing

Prerequisites

Before you start, please note that the ability to use following technologies is required and that existing contributors will not actively teach them to you.

• Basic Android development
• Kotlin
• Web scraping
  • HTML
  • CSS selectors
  • OkHttp
  • JSoup

Tools

• Android Studio
• Emulator or phone with developer options enabled and a recent version of Tachiyomi installed

Getting help

• Join the Discord server for online help and to ask questions while developing your extension.
• There are some features and tricks that are not explored in this document. Refer to existing extension code for examples.

Writing an extension

The quickest way to get started is to copy an existing extension's folder structure and renaming it as needed. We also recommend reading through a few existing extensions' code before you start.

Setting up a new Gradle module

Each extension should reside in src/<lang>/<mysourcename>. Use all as <lang> if your target source supports multiple languages or if it could support multiple sources.

Extension file structure

The simplest extension structure looks like this:

$ tree src/<lang>/<mysourcename>/
src/<lang>/<mysourcename>/
├── AndroidManifest.xml
├── build.gradle
├── res
│   ├── mipmap-hdpi
│   │   └── ic_launcher.png
│   ├── mipmap-mdpi
│   │   └── ic_launcher.png
│   ├── mipmap-xhdpi
│   │   └── ic_launcher.png
│   ├── mipmap-xxhdpi
│   │   └── ic_launcher.png
│   ├── mipmap-xxxhdpi
│   │   └── ic_launcher.png
│   └── web_hi_res_512.png
└── src
    └── eu
        └── kanade
            └── tachiyomi
                └── extension
                    └── <lang>
                        └── <mysourcename>
                            └── <MySourceName>.kt

13 directories, 9 files

AndroidManifest.xml

A minimal Android manifest file is needed for Android to recognize a extension when it's compiled into an APK file. You can also add intent filters inside this file (see URL intent filter for more information).

build.gradle

Make sure that your new extension's build.gradle file follows the following structure:

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'

ext {
    extName = '<My source name>'
    pkgNameSuffix = '<lang>.<mysourcename>'
    extClass = '.<MySourceName>'
    extVersionCode = 1
    libVersion = '1.2'
    containsNsfw = true
}

apply from: "$rootDir/common.gradle"

Field	Description
extName	The name of the extension.
pkgNameSuffix	A unique suffix added to eu.kanade.tachiyomi.extension. The language and the site name should be enough. Remember your extension code implementation must be placed in this package.
extClass	Points to the class that implements Source. You can use a relative path starting with a dot (the package name is the base path). This is used to find and instantiate the source(s).
extVersionCode	The extension version code. This must be a positive integer and incremented with any change to the code.
libVersion	The version of the extensions library used.
containsNsfw	(Optional, defaults to false) Flag to indicate that a source contains NSFW content.

The extension's version name is generated automatically by concatenating libVersion and extVersionCode. With the example used above, the version would be 1.2.1.

Core dependencies

Extension API

Extensions rely on extensions-lib, which provides some interfaces and stubs from the app for compilation purposes. The actual implementations can be found here. Referencing the actual implementation will help with understanding extensions' call flow.

Duktape stub

duktape-stub provides stubs for using Duktape functionality without pulling in the full library. Functionality is bundled into the main Tachiyomi app.

dependencies {
    compileOnly project(':duktape-stub')
}

Rate limiting library

lib-ratelimit is a library for adding rate limiting functionality as an OkHttp interceptor.

dependencies {
    implementation project(':lib-ratelimit')
}

DataImage library

lib-dataimage is a library for handling base 64 encoded image data using an OkHttp interceptor.

dependencies {
    implementation project(':lib-dataimage')
}

Additional dependencies

You may find yourself needing additional functionality and wanting to add more dependencies to your build.gradle file. Since extensions are run within the main Tachiyomi app, you can make use of its dependencies.

For example, an extension that needs Gson could add the following:

dependencies {
    compileOnly 'com.google.code.gson:gson:2.8.2'
}

(Note that Gson, and several other dependencies, are already exposed to all extensions via common.gradle.)

Notice that we're using compileOnly instead of implementation, since the app already contains it. You could use implementation instead for a new dependency, or you prefer not to rely on whatever the main app has at the expense of app size.

Note that using compileOnly restricts you to versions that must be compatible with those used in Tachiyomi v0.8.5+ for proper backwards compatibility.

Extension main class

The class which is refrenced and defined by extClass in build.gradle. This class should implement either SourceFactory or one of the Source implementations: HttpSource or ParsedHttpSource.

Class	Description
SourceFactory	Used to expose multiple Sources. Use it when there's minor differences between your target sources or they are essentially mirrors to the same website.
HttpSource	For online source, where requests are made using HTTP.
ParsedHttpSource	Similar to HttpSource, but has methods useful for scraping pages.

Main class key variables

Field	Description
name	Name displayed in the "Sources" tab in Tachiyomi.
baseUrl	Base URL of the source without any trailing slashes.
lang	An ISO 639-1 compliant language code (two letters in lower case).
id	Identifier of your source, automatically set in HttpSource. It should only be manually overriden if you need to copy an existing autogenerated ID.

Extension call flow

Popular Manga

a.k.a. the Browse source entry point in the app (invoked by tapping on the source name).

• The app calls fetchPopularManga which should return a MangasPage containing the first batch of found SManga entries.
  • This method supports pagination. When user scrolls the manga list and more results must be fetched, the app calls it again with increasing page values(starting with page=1). This continues until MangasPage.hasNextPage is passed as true and MangasPage.mangas is not empty.
• To show the list properly, the app needs url, title and thumbnail_url. You must set them here. The rest of the fields could be filled later.(refer to Manga Details below)
  • You should set thumbnail_url if is available, if not, fetchMangaDetails will be immediately called.(this will increase network calls heavily and should be avoided)

Latest Manga

a.k.a. the Latest source entry point in the app (invoked by tapping on the "Latest" button beside the source name).

• Enabled if supportsLatest is true for a source
• Similar to popular manga, but should be fetching the latest entries from a source.

Manga Search

• When the user searches inside the app, fetchSearchManga will be called and the rest of the flow is similar to what happens with fetchPopularManga.
  • If search functionality is not available, return Observable.just(MangasPage(emptyList(), false))
• getFilterList will be called to get all filters and filter types. TODO: explain more about Filter

Manga Details

• When user taps on a manga, fetchMangaDetails and fetchChapterList will be called and the results will be cached.
  • A SManga entry is identified by it's url.
• fetchMangaDetails is called to update a manga's details from when it was initialized earlier.
  • SManga.initialized tells the app if it should call fetchMangaDetails. If you are overriding fetchMangaDetails, make sure to pass it as true.
  • SManga.genre is a string containing list of all genres separated with ", ".
  • SManga.status is an "enum" value. Refer to the values in the SManga companion object.
  • During a backup, only url and title are stored. To restore the rest of the manga data, the app calls fetchMangaDetails, so all fields should be (re)filled in if possible.
  • If a SManga is cached fetchMangaDetails will be only called when the user does a manual update(Swipe-to-Refresh).
• fetchChapterList is called to display the chapter list.
  • The list should be sorted descending by the source order.
  • If Page.imageUrls are available immediately, you should pass them here. Otherwise, you should set page.url to a page that contains them and override imageUrlParse to fill those imageUrls.

Chapter

• After a chapter list for the manga is fetched and the app is going to cache the data, prepareNewChapter will be called.
• SChapter.date_upload is the UNIX Epoch time expressed in miliseconds.
  • If you don't pass SChapter.date_upload, the user won't get notifications for new chapters. refer to this issue for more info. System.currentTimeMillis() works as a substitute when real data is not available.

Chapter Pages

• When user opens a chapter, fetchPageList will be called and it will return a list of Pages.
• While a chapter is open in the reader or is being downloaded, fetchImageUrl will be called to get URLs for each page of the manga.
• Chapter pages numbers start from 0.

Misc notes

• Sometimes you may find no use for some inherited methods. If so just override them and throw exceptions: throw UnsupportedOperationException("Not used.")
• You probably will find getUrlWithoutDomain useful when parsing the target source URLs.
• If possible try to stick to the general workflow from HttpSource/ParsedHttpSource; breaking them may cause you more headache than necessary.
• By implementing ConfigurableSource you can add settings to your source, which is backed by SharedPreferences.

Advanced Extension features

URL intent filter

Extensions can define URL intent filters by defining it inside a custom AndroidManifest.xml file. For an example, refer to the NHentai module's AndroidManifest.xml file and its corresponding NHUrlActivity handler.

Running

To aid in local development, you can use the following run configuration to launch an extension:

If you're running a Preview or debug build of Tachiyomi:

-W -S -n eu.kanade.tachiyomi.debug/eu.kanade.tachiyomi.ui.main.MainActivity -a eu.kanade.tachiyomi.SHOW_CATALOGUES

And for a release build of Tachiyomi:

-W -S -n eu.kanade.tachiyomi/eu.kanade.tachiyomi.ui.main.MainActivity -a eu.kanade.tachiyomi.SHOW_CATALOGUES

Debugging

Directly debugging your extension (i.e stepping through the extension code) is not possible due to the way that extension code is loaded into the app. However, logs printed from extensions (via Logcat) do work.

Building

APKs can be created in Android Studio via Build > Build Bundle(s) / APK(s) > Build APK(s) or Build > Generate Signed Bundle / APK.