Files
dioxus/packages/autofmt/src/element.rs
T

455 lines
14 KiB
Rust

use crate::{ifmt_to_string, Writer};
use dioxus_rsx::*;
use proc_macro2::Span;
use quote::ToTokens;
use std::{
fmt::Result,
fmt::{self, Write},
};
use syn::{spanned::Spanned, token::Brace, Expr};
#[derive(Debug)]
enum ShortOptimization {
/// Special because we want to print the closing bracket immediately
///
/// IE
/// `div {}` instead of `div { }`
Empty,
/// Special optimization to put everything on the same line and add some buffer spaces
///
/// IE
///
/// `div { "asdasd" }` instead of a multiline variant
Oneliner,
/// Optimization where children flow but props remain fixed on top
PropsOnTop,
/// The noisiest optimization where everything flows
NoOpt,
}
/*
// whitespace
div {
// some whitespace
class: "asdasd"
// whjiot
asdasd // whitespace
}
*/
impl Writer<'_> {
pub fn write_element(&mut self, el: &Element) -> Result {
let Element {
name,
key,
attributes,
children,
brace,
..
} = el;
/*
1. Write the tag
2. Write the key
3. Write the attributes
4. Write the children
*/
write!(self.out, "{name} {{")?;
// decide if we have any special optimizations
// Default with none, opt the cases in one-by-one
let mut opt_level = ShortOptimization::NoOpt;
// check if we have a lot of attributes
let attr_len = self.is_short_attrs(attributes);
let is_short_attr_list = (attr_len + self.out.indent_level * 4) < 80;
let children_len = self.is_short_children(children);
let is_small_children = children_len.is_some();
// if we have few attributes and a lot of children, place the attrs on top
if is_short_attr_list && !is_small_children {
opt_level = ShortOptimization::PropsOnTop;
}
// even if the attr is long, it should be put on one line
if !is_short_attr_list && attributes.len() <= 1 {
if children.is_empty() {
opt_level = ShortOptimization::Oneliner;
} else {
opt_level = ShortOptimization::PropsOnTop;
}
}
// if we have few children and few attributes, make it a one-liner
if is_short_attr_list && is_small_children {
if children_len.unwrap() + attr_len + self.out.indent_level * 4 < 100 {
opt_level = ShortOptimization::Oneliner;
} else {
opt_level = ShortOptimization::PropsOnTop;
}
}
// If there's nothing at all, empty optimization
if attributes.is_empty() && children.is_empty() && key.is_none() {
opt_level = ShortOptimization::Empty;
// Write comments if they exist
self.write_todo_body(brace)?;
}
// multiline handlers bump everything down
if attr_len > 1000 {
opt_level = ShortOptimization::NoOpt;
}
match opt_level {
ShortOptimization::Empty => {}
ShortOptimization::Oneliner => {
write!(self.out, " ")?;
self.write_attributes(attributes, key, true)?;
if !children.is_empty() && (!attributes.is_empty() || key.is_some()) {
write!(self.out, ", ")?;
}
for (id, child) in children.iter().enumerate() {
self.write_ident(child)?;
if id != children.len() - 1 && children.len() > 1 {
write!(self.out, ", ")?;
}
}
write!(self.out, " ")?;
}
ShortOptimization::PropsOnTop => {
if !attributes.is_empty() || key.is_some() {
write!(self.out, " ")?;
}
self.write_attributes(attributes, key, true)?;
if !children.is_empty() && (!attributes.is_empty() || key.is_some()) {
write!(self.out, ",")?;
}
if !children.is_empty() {
self.write_body_indented(children)?;
}
self.out.tabbed_line()?;
}
ShortOptimization::NoOpt => {
self.write_attributes(attributes, key, false)?;
if !children.is_empty() && (!attributes.is_empty() || key.is_some()) {
write!(self.out, ",")?;
}
if !children.is_empty() {
self.write_body_indented(children)?;
}
self.out.tabbed_line()?;
}
}
write!(self.out, "}}")?;
Ok(())
}
fn write_attributes(
&mut self,
attributes: &[AttributeType],
key: &Option<IfmtInput>,
sameline: bool,
) -> Result {
let mut attr_iter = attributes.iter().peekable();
if let Some(key) = key {
if !sameline {
self.out.indented_tabbed_line()?;
}
write!(self.out, "key: {}", ifmt_to_string(key))?;
if !attributes.is_empty() {
write!(self.out, ",")?;
if sameline {
write!(self.out, " ")?;
}
}
}
while let Some(attr) = attr_iter.next() {
self.out.indent_level += 1;
if !sameline {
self.write_comments(attr.start())?;
}
self.out.indent_level -= 1;
if !sameline {
self.out.indented_tabbed_line()?;
}
self.write_attribute(attr)?;
if attr_iter.peek().is_some() {
write!(self.out, ",")?;
if sameline {
write!(self.out, " ")?;
}
}
}
Ok(())
}
fn write_attribute_name(&mut self, attr: &ElementAttrName) -> Result {
match attr {
ElementAttrName::BuiltIn(name) => {
write!(self.out, "{}", name)?;
}
ElementAttrName::Custom(name) => {
write!(self.out, "{}", name.to_token_stream())?;
}
}
Ok(())
}
fn write_attribute_value(&mut self, value: &ElementAttrValue) -> Result {
match value {
ElementAttrValue::AttrOptionalExpr { condition, value } => {
write!(
self.out,
"if {condition} {{ ",
condition = prettyplease::unparse_expr(condition),
)?;
self.write_attribute_value(value)?;
write!(self.out, " }}")?;
}
ElementAttrValue::AttrLiteral(value) => {
write!(self.out, "{value}", value = ifmt_to_string(value))?;
}
ElementAttrValue::AttrExpr(value) => {
let out = prettyplease::unparse_expr(value);
let mut lines = out.split('\n').peekable();
let first = lines.next().unwrap();
// a one-liner for whatever reason
// Does not need a new line
if lines.peek().is_none() {
write!(self.out, "{first}")?;
} else {
writeln!(self.out, "{first}")?;
while let Some(line) = lines.next() {
self.out.indented_tab()?;
write!(self.out, "{line}")?;
if lines.peek().is_none() {
write!(self.out, "")?;
} else {
writeln!(self.out)?;
}
}
}
}
ElementAttrValue::EventTokens(tokens) => {
let out = self.retrieve_formatted_expr(tokens).to_string();
let mut lines = out.split('\n').peekable();
let first = lines.next().unwrap();
// a one-liner for whatever reason
// Does not need a new line
if lines.peek().is_none() {
write!(self.out, "{first}")?;
} else {
writeln!(self.out, "{first}")?;
while let Some(line) = lines.next() {
self.out.indented_tab()?;
write!(self.out, "{line}")?;
if lines.peek().is_none() {
write!(self.out, "")?;
} else {
writeln!(self.out)?;
}
}
}
}
}
Ok(())
}
fn write_attribute(&mut self, attr: &AttributeType) -> Result {
match attr {
AttributeType::Named(attr) => self.write_named_attribute(attr),
AttributeType::Spread(attr) => self.write_spread_attribute(attr),
}
}
fn write_named_attribute(&mut self, attr: &ElementAttrNamed) -> Result {
self.write_attribute_name(&attr.attr.name)?;
write!(self.out, ": ")?;
self.write_attribute_value(&attr.attr.value)?;
Ok(())
}
fn write_spread_attribute(&mut self, attr: &Expr) -> Result {
write!(self.out, "..")?;
write!(self.out, "{}", prettyplease::unparse_expr(attr))?;
Ok(())
}
// make sure the comments are actually relevant to this element.
// test by making sure this element is the primary element on this line
pub fn current_span_is_primary(&self, location: Span) -> bool {
let start = location.start();
let line_start = start.line - 1;
let beginning = self
.src
.get(line_start)
.filter(|this_line| this_line.len() > start.column)
.map(|this_line| this_line[..start.column].trim())
.unwrap_or_default();
beginning.is_empty()
}
// check if the children are short enough to be on the same line
// We don't have the notion of current line depth - each line tries to be < 80 total
// returns the total line length if it's short
// returns none if the length exceeds the limit
// I think this eventually becomes quadratic :(
pub fn is_short_children(&mut self, children: &[BodyNode]) -> Option<usize> {
if children.is_empty() {
// todo: allow elements with comments but no children
// like div { /* comment */ }
// or
// div {
// // some helpful
// }
return Some(0);
}
for child in children {
if self.current_span_is_primary(child.span()) {
'line: for line in self.src[..child.span().start().line - 1].iter().rev() {
match (line.trim().starts_with("//"), line.is_empty()) {
(true, _) => return None,
(_, true) => continue 'line,
_ => break 'line,
}
}
}
}
match children {
[BodyNode::Text(ref text)] => Some(ifmt_to_string(text).len()),
[BodyNode::Component(ref comp)] => {
let attr_len = self.field_len(&comp.fields, &comp.manual_props);
if attr_len > 80 {
None
} else if comp.children.is_empty() {
Some(attr_len)
} else {
None
}
}
// TODO: let rawexprs to be inlined
[BodyNode::RawExpr(ref expr)] => get_expr_length(expr),
[BodyNode::Element(ref el)] => {
let attr_len = self.is_short_attrs(&el.attributes);
if el.children.is_empty() && attr_len < 80 {
return Some(el.name.to_string().len());
}
if el.children.len() == 1 {
if let BodyNode::Text(ref text) = el.children[0] {
let value = ifmt_to_string(text);
if value.len() + el.name.to_string().len() + attr_len < 80 {
return Some(value.len() + el.name.to_string().len() + attr_len);
}
}
}
None
}
// todo, allow non-elements to be on the same line
items => {
let mut total_count = 0;
for item in items {
match item {
BodyNode::Component(_) | BodyNode::Element(_) => return None,
BodyNode::Text(text) => {
total_count += ifmt_to_string(text).len();
}
BodyNode::RawExpr(expr) => match get_expr_length(expr) {
Some(len) => total_count += len,
None => return None,
},
BodyNode::ForLoop(_forloop) => return None,
BodyNode::IfChain(_chain) => return None,
}
}
Some(total_count)
}
}
}
/// empty everything except for some comments
fn write_todo_body(&mut self, brace: &Brace) -> fmt::Result {
let span = brace.span.span();
let start = span.start();
let end = span.end();
if start.line == end.line {
return Ok(());
}
writeln!(self.out)?;
for idx in start.line..end.line {
let line = &self.src[idx];
if line.trim().starts_with("//") {
for _ in 0..self.out.indent_level + 1 {
write!(self.out, " ")?
}
writeln!(self.out, "{}", line.trim()).unwrap();
}
}
for _ in 0..self.out.indent_level {
write!(self.out, " ")?
}
Ok(())
}
}
fn get_expr_length(expr: &Expr) -> Option<usize> {
let span = expr.span();
let (start, end) = (span.start(), span.end());
if start.line == end.line {
Some(end.column - start.column)
} else {
None
}
}