Después de haber trabajado en un proyecto durante un tiempo, puedes encontrar que el proyecto de manera gradual va tomando forma con sus propios ajustes, carpetas, *buffers*, diseños, etc. Es como decorar tu apartamento después de vivir en el durante un tiempo. Es problema es, que cuando cierras Vim, pierdes esos cambios. ¿No sería genial si pudieras mantener esos cambios para que la próxima vez que abras Vim, pareciera que nunca lo hubieras cerrado?
Una vista es el subconjunto más pequeño de los tres temas de este capítulo (vista, sesiones, Viminfo). Es una colección de ajustes para una ventana. Si pasas mucho tiempo trabajando en una ventana y quieres preservar los mapas y carpetas, puedes utilizar una vista.
1. En la línea 1, crea un pliegue de texto (fold) manual con `zf4j` (pliega el contenido de las cuatro líneas siguientes).
2. Cambia el ajuste de la numeración de las líneas `number`: `setlocal nonumber norelativenumber`. Esto eliminará los indicadores de número de la parte izquierda de la ventana.
3. Crea un mapeado local para bajar dos líneas cada vez que presiones `j` en vez de solo una línea, mediante `:nnoremap <buffer> j jj`.
Let's configure `viewoptions`. The three attributes you want to preserve are the folds, the maps, and the local set options. If your setting looks like mine, you already have the `folds` option. You need to tell View to remember the `localoptions`. Run:
You might wonder, "Where did Vim save this View file?" To see where Vim saves it, run:
```
:set viewdir?
```
The default should say `~/.vim/view` (if you have a different OS, it might show a different path. Check out `:h viewdir` for more). If you want to change it to a different path, add this into your vimrc:
The folds, local settings, and local mappings are restored. If you notice, your cursor should also be on the line where you left it when you ran `:mkview`. As long as you have the `cursor` option, View also remembers your cursor position.
One of the worst things that can happen is, after spending countless hours organizing a large file with folds, you accidentally close the window and lose all fold information. To prevent this, you might want to automatically create a View each time you close a buffer. Add this in your vimrc:
Now you don't have to worry about creating and loading View anymore when you are working with `txt` files. Keep in mind that over time, your `~/.vim/view` might start to accumulate View files. It's good to clean it up once every few months.
## Sessions
If a View saves the settings of a window, a Session saves the information of all windows (including the layout).
Unlike `mkview` where it saves to `~/.vim/view` by default, `mksession` saves a Session file (`Session.vim`) in the current directory. Check out the file if you're curious what's inside.
If you want to save the Session file somewhere else, you can pass an argument to `mksession`:
```
:mksession ~/some/where/else.vim
```
If you want to overwrite the existing Session file, call the command with a `!` (`:mksession! ~/some/where/else.vim`).
Session is a useful tool to preserve your project's external attributes. However, some internal attributes aren't saved by Session, like local marks, registers, histories, etc. To save them, you need to use Viminfo!
If you notice, after yanking a word into register a and quitting Vim, the next time you open Vim you still that text stored in the register. This is actually a work of Viminfo. Without it, Vim won't remember the register after you close Vim.
Unlike Session where you can have one Session file per project, you normally will use one Viminfo file per computer. Viminfo is project-agnostic.
The default Viminfo location for Unix is `$HOME/.viminfo` (`~/.viminfo`). If you use a different OS, your Viminfo location might be different. Check out `:h viminfo-file-name`. Each time you make "internal" changes, like yanking a text into a register, Vim automatically updates the Viminfo file.
*Make sure that you have `nocompatible` option set (`set nocompatible`), otherwise your Viminfo will not work.*
Although you will use only one Viminfo file, you can create multiple Viminfo files. To write a Viminfo file, use the `:wviminfo` command (`:wv` for short).
```
:wv ~/.viminfo_extra
```
To overwrite an existing Viminfo file, add a bang to the `wv` command:
```
:wv! ~/.viminfo_extra
```
By default Vim will read from `~/.viminfo` file. To read from a different Viminfo file, run `:rviminfo`, or `:rv` for short:
-`!` saves global variables that start with an uppercase letter and don't contain lowercase letters. Recall that `g:` indicates a global variable. For example, if at some point you wrote the assignment `let g:FOO = "foo"`, Viminfo will save the global variable `FOO`. However if you did `let g:Foo = "foo"`, Viminfo will not save this global variable because it contains lowercase letters. Without `!`, Vim won't safe those global variables.
-`'100` represents marks. In this case, Viminfo will save the local marks (a-z) of the last 100 files. Be aware that if you tell Viminfo to save too many files, Vim can start slowing down. 1000 is a good number to have.
-`<50` tells Viminfo how many maximum lines are saved for each registers (50 in this case). If I yank 100 lines of text into register a (`"ay99j`) and close Vim, the next time I open Vim and paste from register a (`"ap`), Vim will only paste 50 lines max. If you don't give maximum line number, *all* lines will be saved. If you give it 0, nothing will be saved.
Vim has View, Session, and Viminfo to take different level of your Vim environment snapshots. For micro projects, use Views. For larger projects, use Sessions. You should take your time to check out all the options that View, Session, and Viminfo offers.
Create your own View, Session, and Viminfo for your own editing style. If you ever need to use Vim outside of your computer, you can just load your settings and you will immediately feel at home!
