work.suroh.tk/node_modules/pug-linker/index.js

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2019-12-02 12:22:45 +00:00
'use strict';
var assert = require('assert');
var walk = require('pug-walk');
function error() {
throw require('pug-error').apply(null, arguments);
}
module.exports = link;
function link(ast) {
assert(ast.type === 'Block', 'The top level element should always be a block');
var extendsNode = null;
if (ast.nodes.length) {
var hasExtends = ast.nodes[0].type === 'Extends';
checkExtendPosition(ast, hasExtends);
if (hasExtends) {
extendsNode = ast.nodes.shift();
}
}
ast = applyIncludes(ast);
ast.declaredBlocks = findDeclaredBlocks(ast);
if (extendsNode) {
var mixins = [];
var expectedBlocks = [];
ast.nodes.forEach(function addNode(node) {
if (node.type === 'NamedBlock') {
expectedBlocks.push(node);
} else if (node.type === 'Block') {
node.nodes.forEach(addNode);
} else if (node.type === 'Mixin' && node.call === false) {
mixins.push(node);
} else {
error('UNEXPECTED_NODES_IN_EXTENDING_ROOT', 'Only named blocks and mixins can appear at the top level of an extending template', node);
}
});
var parent = link(extendsNode.file.ast);
extend(parent.declaredBlocks, ast);
var foundBlockNames = [];
walk(parent, function (node) {
if (node.type === 'NamedBlock') {
foundBlockNames.push(node.name);
}
});
expectedBlocks.forEach(function (expectedBlock) {
if (foundBlockNames.indexOf(expectedBlock.name) === -1) {
error(
'UNEXPECTED_BLOCK',
'Unexpected block ' + expectedBlock.name,
expectedBlock
);
}
});
Object.keys(ast.declaredBlocks).forEach(function (name) {
parent.declaredBlocks[name] = ast.declaredBlocks[name];
});
parent.nodes = mixins.concat(parent.nodes);
parent.hasExtends = true;
return parent;
}
return ast;
}
function findDeclaredBlocks(ast) /*: {[name: string]: Array<BlockNode>}*/ {
var definitions = {};
walk(ast, function before(node) {
if (node.type === 'NamedBlock' && node.mode === 'replace') {
definitions[node.name] = definitions[node.name] || [];
definitions[node.name].push(node);
}
});
return definitions;
}
function flattenParentBlocks(parentBlocks, accumulator) {
accumulator = accumulator || [];
parentBlocks.forEach(function (parentBlock) {
if (parentBlock.parents) {
flattenParentBlocks(parentBlock.parents, accumulator);
}
accumulator.push(parentBlock);
});
return accumulator;
}
function extend(parentBlocks, ast) {
var stack = {};
walk(ast, function before(node) {
if (node.type === 'NamedBlock') {
if (stack[node.name] === node.name) {
return node.ignore = true;
}
stack[node.name] = node.name;
var parentBlockList = parentBlocks[node.name] ? flattenParentBlocks(parentBlocks[node.name]) : [];
if (parentBlockList.length) {
node.parents = parentBlockList;
parentBlockList.forEach(function (parentBlock) {
switch (node.mode) {
case 'append':
parentBlock.nodes = parentBlock.nodes.concat(node.nodes);
break;
case 'prepend':
parentBlock.nodes = node.nodes.concat(parentBlock.nodes);
break;
case 'replace':
parentBlock.nodes = node.nodes;
break;
}
});
}
}
}, function after(node) {
if (node.type === 'NamedBlock' && !node.ignore) {
delete stack[node.name];
}
});
}
function applyIncludes(ast, child) {
return walk(ast, function before(node, replace) {
if (node.type === 'RawInclude') {
replace({type: 'Text', val: node.file.str.replace(/\r/g, '')});
}
}, function after(node, replace) {
if (node.type === 'Include') {
var childAST = link(node.file.ast);
if (childAST.hasExtends) {
childAST = removeBlocks(childAST);
}
replace(applyYield(childAST, node.block));
}
});
}
function removeBlocks(ast) {
return walk(ast, function (node, replace) {
if (node.type === 'NamedBlock') {
replace({
type: 'Block',
nodes: node.nodes
});
}
});
}
function applyYield(ast, block) {
if (!block || !block.nodes.length) return ast;
var replaced = false;
ast = walk(ast, null, function (node, replace) {
if (node.type === 'YieldBlock') {
replaced = true;
node.type = 'Block';
node.nodes = [block];
}
});
function defaultYieldLocation(node) {
var res = node;
for (var i = 0; i < node.nodes.length; i++) {
if (node.nodes[i].textOnly) continue;
if (node.nodes[i].type === 'Block') {
res = defaultYieldLocation(node.nodes[i]);
} else if (node.nodes[i].block && node.nodes[i].block.nodes.length) {
res = defaultYieldLocation(node.nodes[i].block);
}
}
return res;
}
if (!replaced) {
// todo: probably should deprecate this with a warning
defaultYieldLocation(ast).nodes.push(block);
}
return ast;
}
function checkExtendPosition(ast, hasExtends) {
var legitExtendsReached = false;
walk(ast, function (node) {
if (node.type === 'Extends') {
if (hasExtends && !legitExtendsReached) {
legitExtendsReached = true;
} else {
error('EXTENDS_NOT_FIRST', 'Declaration of template inheritance ("extends") should be the first thing in the file. There can only be one extends statement per file.', node);
}
}
});
}