Files
2024-07-05 13:46:23 +02:00

168 lines
4.2 KiB
JavaScript

'use strict';
var escapeRegExp = require('escape-string-regexp');
var SIMPLE_PLACEHOLDER_RX = /^\[(id|name|file|query|filebase)]/i;
var HASH_PLACEHOLDER_RX = /^\[((?:full)?(?:chunk)?hash)(?::(\d+))?]/i;
var templateCache = Object.create(null);
module.exports = function createTemplate(str) {
if (!templateCache[str]) {
templateCache[str] = new PathTemplate(str);
}
return templateCache[str];
};
function PathTemplate(template) {
this.template = template;
this.fields = parseTemplate(template);
this.matcher = createTemplateMatcher(this.fields);
}
PathTemplate.prototype = {
constructor: PathTemplate,
/**
* Returns whether the given path matches this template.
*
* @param String data
*/
matches: function matches(path) {
return this.matcher.test(path);
},
/**
* Applies data to this template and outputs a filename.
*
* @param Object data
*/
resolve: function resolve(data) {
return this.fields.reduce(function (output, field) {
var replacement = '';
var placeholder = field.placeholder;
var width = field.width;
if (field.prefix) {
output += field.prefix;
}
if (placeholder) {
replacement = data[placeholder] || '';
if (width && (placeholder === 'hash' || placeholder === 'fullhash' || placeholder === 'chunkhash')) {
replacement = replacement.slice(0, width);
}
output += replacement;
}
return output;
}, '');
}
/**
* Loop over the template string and return an array of objects in the form:
* {
* prefix: 'literal text',
* placeholder: 'replacement field name'
* [, width: maximum hash length for hash & chunkhash placeholders]
* }
*
* The values in the object conceptually represent a span of literal text followed by a single replacement field.
* If there is no literal text (which can happen if two replacement fields occur consecutively),
* then prefix will be an empty string.
* If there is no replacement field, then the value of placeholder will be null.
* If the value of placeholder is either 'hash', 'fullhash', or 'chunkhash', then width will be a positive integer.
* Otherwise it will be left undefined.
*/
};function parseTemplate(str) {
var fields = [];
var char = '';
var pos = 0;
var prefix = '';
var match = null;
var input = void 0;
while (true) {
// eslint-disable-line no-constant-condition
char = str[pos];
if (!char) {
fields.push({
prefix: prefix,
placeholder: null
});
break;
} else if (char === '[') {
input = str.slice(pos);
match = SIMPLE_PLACEHOLDER_RX.exec(input);
if (match) {
fields.push({
prefix: prefix,
placeholder: match[1].toLowerCase()
});
pos += match[0].length;
prefix = '';
continue;
}
match = HASH_PLACEHOLDER_RX.exec(input);
if (match) {
fields.push({
prefix: prefix,
placeholder: match[1].toLowerCase(),
width: parseInt(match[2] || 0, 10)
});
pos += match[0].length;
prefix = '';
continue;
}
}
prefix += char;
pos++;
}
return fields;
}
/**
* Returns a RegExp which, given the replacement fields returned by parseTemplate(),
* can match a file path against a path template.
*/
function createTemplateMatcher(fields) {
var length = fields.length;
var pattern = fields.reduce(function (pattern, field, i) {
if (i === 0) {
pattern = '^';
}
if (field.prefix) {
pattern += '(' + escapeRegExp(field.prefix) + ')';
}
if (field.placeholder) {
switch (field.placeholder) {
case 'hash':
case 'fullhash':
case 'chunkhash':
pattern += '[0-9a-fA-F]';
pattern += field.width ? '{1,' + field.width + '}' : '+';
break;
case 'id':
case 'name':
case 'file':
case 'filebase':
pattern += '.+?';
break;
case 'query':
pattern += '(?:\\?.+?)?';
break;
}
}
if (i === length - 1) {
pattern += '$';
}
return pattern;
}, '');
return new RegExp(pattern);
}