#+TITLE: Search Engine layer

#+TAGS: layer|web service

[[file:img/searchengine.jpg]]

* Table of Contents                     :TOC_5_gh:noexport:
- [[#description][Description]]
  - [[#features][Features:]]
- [[#supported-search-engines][Supported search engines]]
- [[#install][Install]]
- [[#key-bindings][Key bindings]]
- [[#customize-it][Customize it!]]

* Description
This layer adds support for the [[https://github.com/hrs/engine-mode][Search Engine]] package.

** Features:
- Browser search integration

* Supported search engines
- Amazon
- Bing
- Duck Duck Go
- Ecosia
- GitHub
- Google
- Google Images
- Google Maps
- Twitter
- Project Gutenberg
- YouTube
- Stack Overflow
- Spacemacs Issues
- Spacemacs Pull Requests
- Wikipedia
- Wolfram Alpha
- Maven Central
- Npm
- Hoogle 5
- Hackage Package Search
- Clojure-doc
- Python Package Index
- Python Docs
- C++ Reference
- Melpa
- Debian Packages
- Ubuntu Packages
- Rails API
- Docker Hub images

* Install
To use this configuration layer, add it to your =~/.spacemacs=. You will need to
add =search-engine= to the existing =dotspacemacs-configuration-layers= list in this
file.

* Key bindings

| Evil        | Holy    | Command                                   |
|-------------+---------+-------------------------------------------|
| ~SPC a w /~ | ~C-c /~ | Summon a Helm buffer to select any engine |

* Customize it!
If you'd rather have emacs use chrome, or firefox or any other thing (=eww=) you
can have that customization. For example for google chrome you can put this in
your =dotspacemacs/user-config=:

#+BEGIN_SRC emacs-lisp
  (setq browse-url-browser-function 'browse-url-generic
        engine/browser-function 'browse-url-generic
        browse-url-generic-program "google-chrome")
#+END_SRC

The Amazon search engine defaults to use the =.com= [[https://en.wikipedia.org/wiki/TLD][TLD]]. If you want it to search on
another country's website, you can specify a different one:

#+BEGIN_SRC emacs-lisp
  ;; Use amazon.es site (Spain)
  (setq-default search-engine-amazon-tld "es")
#+END_SRC

If you want more control of how various search engines are handled
or you want to add additional ones you can do so by setting the
following datastructure to =search-engine-config-list= in your =dotspacemacs/user-config=.

The datastructure consists of a key and:
- name -> the name displayed in the search prompt.
- url -> the url to query against, search parameter must be set as =%s=.
- keywords -> a list of =engine-mode= keywords like a specific browser to use
  or a specific transformation to make. You can find a detailed
  list of all supported features [[https://github.com/hrs/engine-mode][here]].

#+BEGIN_SRC emacs-lisp
  (setq-default dotspacemacs-configuration-layers
    '((search-engine :variables
                     search-engine-config-list '((custom1
                                                  :name "Custom Search Engine 1"
                                                  :url "http://www.domain.com/s/stuff_sutff_remember_to_replace_search_candidate_with_%s"
                                                  :keywords (:docstring "My custom string"
                                                                        :browser 'eww-browse-url))))))
#+END_SRC

If you'd rather not use helm but would want a specific search engine, remember
the function generated is always =engine/search-(the name of the search engine
lower-case and hyphen instead-of-spaces-for-separation)= so you can bind that to
any key binding you want.