function compressChunk(ast, firstAtrulesAllowed, usageData, num, logger) {
logger('Compress block #' + num, null, true);
var seed = 1;
if (ast.type === 'StyleSheet') {
ast.firstAtrulesAllowed = firstAtrulesAllowed;
ast.id = seed++;
}
walkRules(ast, function markScopes(node) {
if (node.type === 'Atrule' && node.block !== null) {
node.block.id = seed++;
}
});
logger('init', ast);
// remove redundant
clean(ast, usageData);
logger('clean', ast);
// replace nodes for shortened forms
replace(ast, usageData);
logger('replace', ast);
return ast;
}
module.exports = function mergeRule(ast) {
walkRules(ast, function(node, item, list) {
if (node.type === 'Rule') {
processRule(node, item, list);
}
});
};
exports.fn = function(document, opts) {
// collect <style/>s
var styleEls = document.querySelectorAll('style');
//no <styles/>s, nothing to do
if (styleEls === null) {
return document;
}
var styles = [],
selectors = [];
for (var styleEl of styleEls) {
if (styleEl.isEmpty() || styleEl.closestElem('foreignObject')) {
// skip empty <style/>s or <foreignObject> content.
continue;
}
var cssStr = cssTools.getCssStr(styleEl);
// collect <style/>s and their css ast
var cssAst = {};
try {
cssAst = csstree.parse(cssStr, {
parseValue: false,
parseCustomProperty: false
});
} catch (parseError) {
// console.warn('Warning: Parse error of styles of <style/> element, skipped. Error details: ' + parseError);
continue;
}
styles.push({
styleEl: styleEl,
cssAst: cssAst
});
selectors = selectors.concat(cssTools.flattenToSelectors(cssAst));
}
// filter for mediaqueries to be used or without any mediaquery
var selectorsMq = cssTools.filterByMqs(selectors, opts.useMqs);
// filter for pseudo elements to be used
var selectorsPseudo = cssTools.filterByPseudos(selectorsMq, opts.usePseudos);
// remove PseudoClass from its SimpleSelector for proper matching
cssTools.cleanPseudos(selectorsPseudo);
// stable sort selectors
var sortedSelectors = cssTools.sortSelectors(selectorsPseudo).reverse();
var selector,
selectedEl;
// match selectors
for (selector of sortedSelectors) {
var selectorStr = csstree.translate(selector.item.data),
selectedEls = null;
try {
selectedEls = document.querySelectorAll(selectorStr);
} catch (selectError) {
if (selectError.constructor === SyntaxError) {
// console.warn('Warning: Syntax error when trying to select \n\n' + selectorStr + '\n\n, skipped. Error details: ' + selectError);
continue;
}
throw selectError;
}
if (selectedEls === null) {
// nothing selected
continue;
}
selector.selectedEls = selectedEls;
}
// apply <style/> styles to matched elements
for (selector of sortedSelectors) {
if(!selector.selectedEls) {
continue;
}
if (opts.onlyMatchedOnce && selector.selectedEls !== null && selector.selectedEls.length > 1) {
// skip selectors that match more than once if option onlyMatchedOnce is enabled
continue;
}
// apply <style/> to matched elements
for (selectedEl of selector.selectedEls) {
if (selector.rule === null) {
continue;
}
// merge declarations
csstree.walkDeclarations(selector.rule, function(styleCsstreeDeclaration) {
// existing inline styles have higher priority
// no inline styles, external styles, external styles used
// inline styles, external styles same priority as inline styles, inline styles used
// inline styles, external styles higher priority than inline styles, external styles used
var styleDeclaration = cssTools.csstreeToStyleDeclaration(styleCsstreeDeclaration);
if (selectedEl.style.getPropertyValue(styleDeclaration.name) !== null &&
selectedEl.style.getPropertyPriority(styleDeclaration.name) >= styleDeclaration.priority) {
return;
}
selectedEl.style.setProperty(styleDeclaration.name, styleDeclaration.value, styleDeclaration.priority);
});
}
if (opts.removeMatchedSelectors && selector.selectedEls !== null && selector.selectedEls.length > 0) {
// clean up matching simple selectors if option removeMatchedSelectors is enabled
selector.rule.prelude.children.remove(selector.item);
}
}
if (!opts.removeMatchedSelectors) {
return document; // no further processing required
}
// clean up matched class + ID attribute values
for (selector of sortedSelectors) {
if(!selector.selectedEls) {
continue;
}
if (opts.onlyMatchedOnce && selector.selectedEls !== null && selector.selectedEls.length > 1) {
// skip selectors that match more than once if option onlyMatchedOnce is enabled
continue;
}
for (selectedEl of selector.selectedEls) {
// class
var firstSubSelector = selector.item.data.children.first();
if(firstSubSelector.type === 'ClassSelector') {
selectedEl.class.remove(firstSubSelector.name);
}
// clean up now empty class attributes
if(typeof selectedEl.class.item(0) === 'undefined') {
selectedEl.removeAttr('class');
}
// ID
if(firstSubSelector.type === 'IdSelector') {
selectedEl.removeAttr('id', firstSubSelector.name);
}
}
}
// clean up now empty elements
for (var style of styles) {
csstree.walkRules(style.cssAst, function(node, item, list) {
// clean up <style/> atrules without any rulesets left
if (node.type === 'Atrule' &&
// only Atrules containing rulesets
node.block !== null &&
node.block.children.isEmpty()) {
list.remove(item);
return;
}
// clean up <style/> rulesets without any css selectors left
if (node.type === 'Rule' &&
node.prelude.children.isEmpty()) {
list.remove(item);
}
});
if (style.cssAst.children.isEmpty()) {
// clean up now emtpy <style/>s
var styleParentEl = style.styleEl.parentNode;
styleParentEl.spliceContent(styleParentEl.content.indexOf(style.styleEl), 1);
if (styleParentEl.elem === 'defs' &&
styleParentEl.content.length === 0) {
// also clean up now empty <def/>s
var defsParentEl = styleParentEl.parentNode;
defsParentEl.spliceContent(defsParentEl.content.indexOf(styleParentEl), 1);
}
continue;
}
// update existing, left over <style>s
cssTools.setCssStr(style.styleEl, csstree.translate(style.cssAst));
}
return document;
};