com.webos.service.unifiedsearch

Searches various items (intents) by using keyword.

Unified search service handles various search targets and allows to find it's items.

Note: This service works tightly with the com.webos.service.intent service.

Search Targets

• Application: Search by title
   
• Application contents: Search by string mapping what app has specified (e.g. Settings). See the "Configuring Application Contents Search" section below.
  Note: Currently, only supports "web" type applications that follow the webOs i18n structure. 
   
• Plugins: Search by plugin (e.g. audio, video, image, contact) 

Note: The service has internal database (sqlite3 FTS3) to index items of application and application contents. For plugins, the service generally searches items from the database (DB8) directly.

Configuring Application Contents Search

To search within the contents of an app, you need to:.

1. Create a mapping JSON file. Check below example.

   search.json

   {
       "items": [{
           "path": "/..../....",    <------------- intent path (search key = uri + path)
           "extra": { ...  },       <------------- extra field of intent (optional)
           "labels": [              <------------- list of resource key
               "Language",
               ...
           ]
       }, ...]
   }

2. In the appinfo.json file, specify the path of the mapping JSON file and the intentFilters.

   appinfo.json

   {
      "....",
      "searchIndex":"search.json",    <------------- mapping JSON file
      "intentFilters":[
         {
            "actions":[
               "view"
            ],
            "uris":[
               "app://$APP_ID$"
            ]
         }
      ],
      "...."
   }

• resources/ilibmanifest.json : will read '*/strings.json' on 'files' array.

• resources/*/strings.json : will load entire key:value into the sqlite3 FTS database.

Since the search API returns the search result as "Intent"s, the app should be able to handle the intent also.

The parameters will come as part of "webOSSystem.launchParams". You can use this to move app page to show the searched content. For example:

Developing plugins

We support the C++ implementation only. Please refer "./plugins/media" as a  plugin template first.

To implement yours, add "com.webos.service.unifiedsearch" to DEPENDS of your component recipe file.
And place the result shared object (.so) file on /usr/lib/plugins/unifiedsearch folder.

The unified search core has following classes to implement plugin.
You need to inherit at least 3 classes (bold items), and need to implement virtual functions.

• Object
  • SearchItem (.h) : a common data format to save/load items
  • Intent (.h) : a format to handle intent, and also display the items on screen
• Controller
  • LunaClient (.h) : to access LS2 as com.webos.service.unifiedsearch contact
  • Category (.h) : a set of item, generating "Intent" from "SearchItem"
  • DataSource (.h) : item store, store/search the "SearchItem" internally
• Bridge
  • SearchSet (.h) : have a DataSource and multiple Category
  • Plugin (.h) : pass a SearchSet to the unified search service

- Plugin workflow

- Implementation steps

1. Inherit and implement DataSource class
   • override "search" function: Search the datasource (for example  DB8) and create SearchItem vector and return it by using callback.
     • Should return all category items that matched with 'searchKey' as async
       (if you handle multiple categories on your plugin)
     • The callback: function<void(string, vector<SearchItemPtr>)>
2. Inherit and implement Category class
   • override "generateIntent" function to convert SearchItem to Intent
     • Generally, you will set 'Action', 'URI' and 'Display' on this stage.
3. Inherit and implement Plugin class
   • create a DataSource and categories
   • create a SearchSet with the DataSource and add created categories
   • override "getSearchSet" to return upper SearchSet
   • create 'extern "C" Plugin* create_plugin()' function to return a pointer of your Plugin (as singleton)

- Using LunaClient class to easy LS2 implementation

1. Inherit & implement LunaClient class
   • It will use the context of 'com.webos.service.unifiedsearch'.
     • So if you want to connect LS2 as another context, please re-implement your own LS2 class.
     • And also, if you want to connect to another ACG group, please add required group to the client permissions file.
       - in source code: files/sysbus/com.webos.service.unifiedsearch.perm.json
       - in target rootfs: /usr/share/luna-service2/client-permissions.d/com.webos.service.unifiedsearch.perm.json
   • Create a function to get your data
     • Use follow function to call, implement as async
       LunaClient::call(string method, string payload, function<bool(LSMessage *message)> cb, bool subscribe)
        

- About the Async implementation

• The unifiedsearch's search API will respond after all data sources' search functions were done.
  Because it requires some async targets (e.g. LS2)
• It's designed 
  1. passing shared_ptr of some 'Task' which has the callback to the lambda function as capture
  2. because of lambda holds the shared_ptr, it will keep the Task until the function ended
  3. and if all lambda functions are done, the Task will be destroyed.
  4. On the destructor of Task, it will call the callback.

getCategories

search

updateCategory

category

display

groupedIntents

intent

item