@mojojs/core
Version:
Real-time web framework
205 lines • 6.87 kB
JavaScript
import { escapeRegExp } from '@mojojs/util';
const OP = {
placeholder: Symbol('placeholder'),
relaxed: Symbol('relaxed'),
slash: Symbol('slash'),
text: Symbol('text'),
wildcard: Symbol('wildcard')
};
/**
* Route pattern class.
*/
export class Pattern {
constructor(path, options = {}) {
/**
* Placeholder names.
*/
this.placeholders = [];
/**
* Pattern in compiled regular expression form.
*/
this.regex = undefined;
/**
* Raw unparsed pattern.
*/
this.unparsed = '';
this._ast = [];
this.constraints = options.constraints ?? {};
this.defaults = options.defaults ?? {};
this.types = options.types ?? {};
if (path !== undefined)
this.parse(path);
}
/**
* Match pattern against entire path.
*/
match(path, options) {
const result = this.matchPartial(path, options);
if (result === null || (result.remainder.length > 0 && result.remainder !== '/'))
return null;
return result.captures;
}
/**
* Match pattern against path and return the remainder.
*/
matchPartial(path, options) {
if (this.regex === undefined)
this.regex = this._compile(options.isEndpoint);
const match = path.match(this.regex);
if (match === null)
return null;
const prefix = match.shift() ?? '';
const captures = { ...this.defaults };
for (const name of [...this.placeholders, 'ext']) {
if (match.length === 0)
break;
const value = match.shift();
if (value !== undefined)
captures[name] = value;
}
return { remainder: path.replace(prefix, ''), captures };
}
/**
* Parse pattern.
*/
parse(path = '') {
this.unparsed = path.replace(/^\/*|\/+/g, '/').replace(/\/$/, '');
this._tokenize();
return this;
}
/**
* Render pattern into a path with parameters.
*/
render(values, options) {
let optional = values.ext == null;
const parts = [];
for (const token of this._ast) {
if (token[0] === OP.slash) {
if (optional === false)
parts.unshift('/');
}
else if (token[0] === OP.text) {
parts.unshift(token[1]);
optional = false;
}
else {
const defaults = this.defaults;
const hasDefault = defaults[token[1]] !== undefined;
const value = hasDefault ? defaults[token[1]] : null;
const part = values[token[1]] !== undefined ? values[token[1]] : value;
if (hasDefault === false || value !== part)
optional = false;
if (optional === false)
parts.unshift(part);
}
}
const path = parts.join('');
return options.isEndpoint && values.ext != null ? `${path}.${values.ext}` : path;
}
_compile(withExtension) {
const parts = [];
let block = '';
let optional = true;
for (const token of this._ast) {
let part = '';
if (token[0] === OP.slash) {
parts.unshift(optional ? `(?:/${block})?` : `/${block}`);
block = '';
optional = true;
continue;
}
else if (token[0] === OP.text) {
part = escapeRegExp(token[1]);
optional = false;
}
else {
if (token.length > 2) {
part = this._compileType(this.types[token[2]] ?? '?!');
}
else if (this.constraints[token[1]] != null) {
part = this._compileType(this.constraints[token[1]]);
}
else {
part = token[0] === OP.wildcard ? '(.*)' : token[0] === OP.relaxed ? '([^/]+)' : '([^/.]+)';
}
if (this.defaults[token[1]] !== undefined) {
part = `${part}?`;
}
else {
optional = false;
}
}
block = part + block;
}
if (withExtension) {
parts.push(this._compileExtension(this.constraints.ext, this.defaults.ext !== undefined));
}
return new RegExp('^' + parts.join(''), 's');
}
_compileExtension(ext, withDefault) {
if (ext === undefined)
return '';
const regex = '\\.' + this._compileType(ext);
return withDefault ? `/?(?:${regex})?$` : `/?${regex}$`;
}
_compileType(type) {
if (type instanceof RegExp)
return `(${type.source})`;
if (!Array.isArray(type))
return `(${type})`;
return ('(' +
type
.slice()
.sort()
.reverse()
.map(val => escapeRegExp(val))
.join('|') +
')');
}
_tokenize() {
let name = false;
const ast = this._ast;
for (const char of this.unparsed) {
if (char === '<') {
ast.push([OP.placeholder, '']);
name = true;
}
else if (char === '>') {
name = false;
}
else if (name === false && char === ':') {
if (name === false)
ast.push([OP.placeholder, '']);
name = true;
}
else if (name === false && (char === '#' || char === '*')) {
if (name === false)
ast.push([char === '#' ? OP.relaxed : OP.wildcard, '']);
name = true;
}
else if (char === '/') {
ast.push([OP.slash]);
name = false;
}
else if (name === true) {
ast[ast.length - 1][1] = ast[ast.length - 1][1].concat(char);
}
else if (ast[ast.length - 1][0] === OP.text) {
ast[ast.length - 1][1] = ast[ast.length - 1][1].concat(char);
}
else {
ast.push([OP.text, char]);
}
}
for (const token of ast) {
if (token[0] === OP.slash || token[0] === OP.text)
continue;
token[0] = /^#/.test(token[1]) ? OP.relaxed : /^\*/.test(token[1]) ? OP.wildcard : token[0];
const typed = token.pop();
token.push(...typed.replace(/^[:#*]/, '').split(':'));
this.placeholders.push(token[1]);
}
ast.reverse();
}
}
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