import { List, generate, walk } from 'css-tree'; const REPLACE = 1; const REMOVE = 2; const TOP = 0; const RIGHT = 1; const BOTTOM = 2; const LEFT = 3; const SIDES = ['top', 'right', 'bottom', 'left']; const SIDE = { 'margin-top': 'top', 'margin-right': 'right', 'margin-bottom': 'bottom', 'margin-left': 'left', 'padding-top': 'top', 'padding-right': 'right', 'padding-bottom': 'bottom', 'padding-left': 'left', 'border-top-color': 'top', 'border-right-color': 'right', 'border-bottom-color': 'bottom', 'border-left-color': 'left', 'border-top-width': 'top', 'border-right-width': 'right', 'border-bottom-width': 'bottom', 'border-left-width': 'left', 'border-top-style': 'top', 'border-right-style': 'right', 'border-bottom-style': 'bottom', 'border-left-style': 'left' }; const MAIN_PROPERTY = { 'margin': 'margin', 'margin-top': 'margin', 'margin-right': 'margin', 'margin-bottom': 'margin', 'margin-left': 'margin', 'padding': 'padding', 'padding-top': 'padding', 'padding-right': 'padding', 'padding-bottom': 'padding', 'padding-left': 'padding', 'border-color': 'border-color', 'border-top-color': 'border-color', 'border-right-color': 'border-color', 'border-bottom-color': 'border-color', 'border-left-color': 'border-color', 'border-width': 'border-width', 'border-top-width': 'border-width', 'border-right-width': 'border-width', 'border-bottom-width': 'border-width', 'border-left-width': 'border-width', 'border-style': 'border-style', 'border-top-style': 'border-style', 'border-right-style': 'border-style', 'border-bottom-style': 'border-style', 'border-left-style': 'border-style' }; class TRBL { constructor(name) { this.name = name; this.loc = null; this.iehack = undefined; this.sides = { 'top': null, 'right': null, 'bottom': null, 'left': null }; } getValueSequence(declaration, count) { const values = []; let iehack = ''; const hasBadValues = declaration.value.type !== 'Value' || declaration.value.children.some(function(child) { let special = false; switch (child.type) { case 'Identifier': switch (child.name) { case '\\0': case '\\9': iehack = child.name; return; case 'inherit': case 'initial': case 'unset': case 'revert': special = child.name; break; } break; case 'Dimension': switch (child.unit) { // is not supported until IE11 case 'rem': // v* units is too buggy across browsers and better // don't merge values with those units case 'vw': case 'vh': case 'vmin': case 'vmax': case 'vm': // IE9 supporting "vm" instead of "vmin". special = child.unit; break; } break; case 'Hash': // color case 'Number': case 'Percentage': break; case 'Function': if (child.name === 'var') { return true; } special = child.name; break; default: return true; // bad value } values.push({ node: child, special, important: declaration.important }); }); if (hasBadValues || values.length > count) { return false; } if (typeof this.iehack === 'string' && this.iehack !== iehack) { return false; } this.iehack = iehack; // move outside return values; } canOverride(side, value) { const currentValue = this.sides[side]; return !currentValue || (value.important && !currentValue.important); } add(name, declaration) { function attemptToAdd() { const sides = this.sides; const side = SIDE[name]; if (side) { if (side in sides === false) { return false; } const values = this.getValueSequence(declaration, 1); if (!values || !values.length) { return false; } // can mix only if specials are equal for (const key in sides) { if (sides[key] !== null && sides[key].special !== values[0].special) { return false; } } if (!this.canOverride(side, values[0])) { return true; } sides[side] = values[0]; return true; } else if (name === this.name) { const values = this.getValueSequence(declaration, 4); if (!values || !values.length) { return false; } switch (values.length) { case 1: values[RIGHT] = values[TOP]; values[BOTTOM] = values[TOP]; values[LEFT] = values[TOP]; break; case 2: values[BOTTOM] = values[TOP]; values[LEFT] = values[RIGHT]; break; case 3: values[LEFT] = values[RIGHT]; break; } // can mix only if specials are equal for (let i = 0; i < 4; i++) { for (const key in sides) { if (sides[key] !== null && sides[key].special !== values[i].special) { return false; } } } for (let i = 0; i < 4; i++) { if (this.canOverride(SIDES[i], values[i])) { sides[SIDES[i]] = values[i]; } } return true; } } if (!attemptToAdd.call(this)) { return false; } // TODO: use it when we can refer to several points in source // if (this.loc) { // this.loc = { // primary: this.loc, // merged: declaration.loc // }; // } else { // this.loc = declaration.loc; // } if (!this.loc) { this.loc = declaration.loc; } return true; } isOkToMinimize() { const top = this.sides.top; const right = this.sides.right; const bottom = this.sides.bottom; const left = this.sides.left; if (top && right && bottom && left) { const important = top.important + right.important + bottom.important + left.important; return important === 0 || important === 4; } return false; } getValue() { const result = new List(); const sides = this.sides; const values = [ sides.top, sides.right, sides.bottom, sides.left ]; const stringValues = [ generate(sides.top.node), generate(sides.right.node), generate(sides.bottom.node), generate(sides.left.node) ]; if (stringValues[LEFT] === stringValues[RIGHT]) { values.pop(); if (stringValues[BOTTOM] === stringValues[TOP]) { values.pop(); if (stringValues[RIGHT] === stringValues[TOP]) { values.pop(); } } } for (let i = 0; i < values.length; i++) { result.appendData(values[i].node); } if (this.iehack) { result.appendData({ type: 'Identifier', loc: null, name: this.iehack }); } return { type: 'Value', loc: null, children: result }; } getDeclaration() { return { type: 'Declaration', loc: this.loc, important: this.sides.top.important, property: this.name, value: this.getValue() }; } } function processRule(rule, shorts, shortDeclarations, lastShortSelector) { const declarations = rule.block.children; const selector = rule.prelude.children.first.id; rule.block.children.forEachRight(function(declaration, item) { const property = declaration.property; if (!MAIN_PROPERTY.hasOwnProperty(property)) { return; } const key = MAIN_PROPERTY[property]; let shorthand; let operation; if (!lastShortSelector || selector === lastShortSelector) { if (key in shorts) { operation = REMOVE; shorthand = shorts[key]; } } if (!shorthand || !shorthand.add(property, declaration)) { operation = REPLACE; shorthand = new TRBL(key); // if can't parse value ignore it and break shorthand children if (!shorthand.add(property, declaration)) { lastShortSelector = null; return; } } shorts[key] = shorthand; shortDeclarations.push({ operation, block: declarations, item, shorthand }); lastShortSelector = selector; }); return lastShortSelector; } function processShorthands(shortDeclarations, markDeclaration) { shortDeclarations.forEach(function(item) { const shorthand = item.shorthand; if (!shorthand.isOkToMinimize()) { return; } if (item.operation === REPLACE) { item.item.data = markDeclaration(shorthand.getDeclaration()); } else { item.block.remove(item.item); } }); } export default function restructBlock(ast, indexer) { const stylesheetMap = {}; const shortDeclarations = []; walk(ast, { visit: 'Rule', reverse: true, enter(node) { const stylesheet = this.block || this.stylesheet; const ruleId = (node.pseudoSignature || '') + '|' + node.prelude.children.first.id; let ruleMap; let shorts; if (!stylesheetMap.hasOwnProperty(stylesheet.id)) { ruleMap = { lastShortSelector: null }; stylesheetMap[stylesheet.id] = ruleMap; } else { ruleMap = stylesheetMap[stylesheet.id]; } if (ruleMap.hasOwnProperty(ruleId)) { shorts = ruleMap[ruleId]; } else { shorts = {}; ruleMap[ruleId] = shorts; } ruleMap.lastShortSelector = processRule.call(this, node, shorts, shortDeclarations, ruleMap.lastShortSelector); } }); processShorthands(shortDeclarations, indexer.declaration); };