diff options
Diffstat (limited to 'runtime/doc')
| -rw-r--r-- | runtime/doc/develop.txt | 46 |
1 files changed, 22 insertions, 24 deletions
diff --git a/runtime/doc/develop.txt b/runtime/doc/develop.txt index 0f9e17e697..180612cf20 100644 --- a/runtime/doc/develop.txt +++ b/runtime/doc/develop.txt @@ -84,12 +84,11 @@ Developer guidelines *dev-guidelines* PROVIDERS *dev-provider* -A goal of Nvim is to allow extension of the editor without special knowledge -in the core. But some Vim components are too tightly coupled; in those cases -a "provider" hook is exposed. +A primary goal of Nvim is to allow extension of the editor without special +knowledge in the core. Some core functions are delegated to "providers" +implemented as external scripts. -Consider two examples of integration with external systems that are -implemented in Vim and are now decoupled from Nvim core as providers: +Examples: 1. In the Vim source code, clipboard logic accounts for more than 1k lines of C source code (ui.c), to perform two tasks that are now accomplished with @@ -101,29 +100,28 @@ implemented in Vim and are now decoupled from Nvim core as providers: scripting is performed by an external host process implemented in ~2k lines of Python. -Ideally we could implement Python and clipboard integration in pure vimscript -and without touching the C code. But this is infeasible without compromising -backwards compatibility with Vim; that's where providers help. +The provider framework invokes VimL from C. It is composed of two functions +in eval.c: -The provider framework helps call vimscript from C. It is composed of two -functions in eval.c: - -- eval_call_provider(name, method, arguments): calls provider#(name)#Call +- eval_call_provider(name, method, arguments): calls provider#{name}#Call with the method and arguments. -- eval_has_provider(name): Checks if a provider is implemented. Returns true - if the provider#(name)#enabled variable is not 0. Called by |has()| - (vimscript) to check if features are available. - -The provider#(name)#Call function implements integration with an external -system, because shell commands and |RPC| clients are easier to work with in -vimscript. +- eval_has_provider(name): Checks the `g:loaded_{name}_provider` variable + which must be set by the provider script to indicate whether it is enabled + and working. Called by |has()| to check if features are available. For example, the Python provider is implemented by the -autoload/provider/python.vim script; the variable provider#python#enabled is only -1 if a valid external Python host is found. That works well with the -`has('python')` expression (normally used by Python plugins) because if the -Python host isn't installed then the plugin will "think" it is running in -a Vim compiled without the "+python" feature. +"autoload/provider/python.vim" script, which sets `g:loaded_python_provider` +to TRUE only if a valid external Python host is found. Then `has("python")` +reflects whether Python support is working. + + *provider-reload* +Sometimes a GUI or other application may want to force a provider to +"reload". To reload a provider, undefine its "loaded" flag, then use +|:runtime| to reload it: > + + :unlet g:loaded_clipboard_provider + :runtime autoload/provider/clipboard.vim + DOCUMENTATION *dev-doc* |