forked from zhurui/management
98 lines
2.8 KiB
JavaScript
98 lines
2.8 KiB
JavaScript
'use strict';
|
|
|
|
/**
|
|
* @param typeMap [Object] Map of MIME type -> Array[extensions]
|
|
* @param ...
|
|
*/
|
|
function Mime() {
|
|
this._types = Object.create(null);
|
|
this._extensions = Object.create(null);
|
|
|
|
for (let i = 0; i < arguments.length; i++) {
|
|
this.define(arguments[i]);
|
|
}
|
|
|
|
this.define = this.define.bind(this);
|
|
this.getType = this.getType.bind(this);
|
|
this.getExtension = this.getExtension.bind(this);
|
|
}
|
|
|
|
/**
|
|
* Define mimetype -> extension mappings. Each key is a mime-type that maps
|
|
* to an array of extensions associated with the type. The first extension is
|
|
* used as the default extension for the type.
|
|
*
|
|
* e.g. mime.define({'audio/ogg', ['oga', 'ogg', 'spx']});
|
|
*
|
|
* If a type declares an extension that has already been defined, an error will
|
|
* be thrown. To suppress this error and force the extension to be associated
|
|
* with the new type, pass `force`=true. Alternatively, you may prefix the
|
|
* extension with "*" to map the type to extension, without mapping the
|
|
* extension to the type.
|
|
*
|
|
* e.g. mime.define({'audio/wav', ['wav']}, {'audio/x-wav', ['*wav']});
|
|
*
|
|
*
|
|
* @param map (Object) type definitions
|
|
* @param force (Boolean) if true, force overriding of existing definitions
|
|
*/
|
|
Mime.prototype.define = function(typeMap, force) {
|
|
for (let type in typeMap) {
|
|
let extensions = typeMap[type].map(function(t) {
|
|
return t.toLowerCase();
|
|
});
|
|
type = type.toLowerCase();
|
|
|
|
for (let i = 0; i < extensions.length; i++) {
|
|
const ext = extensions[i];
|
|
|
|
// '*' prefix = not the preferred type for this extension. So fixup the
|
|
// extension, and skip it.
|
|
if (ext[0] === '*') {
|
|
continue;
|
|
}
|
|
|
|
if (!force && (ext in this._types)) {
|
|
throw new Error(
|
|
'Attempt to change mapping for "' + ext +
|
|
'" extension from "' + this._types[ext] + '" to "' + type +
|
|
'". Pass `force=true` to allow this, otherwise remove "' + ext +
|
|
'" from the list of extensions for "' + type + '".'
|
|
);
|
|
}
|
|
|
|
this._types[ext] = type;
|
|
}
|
|
|
|
// Use first extension as default
|
|
if (force || !this._extensions[type]) {
|
|
const ext = extensions[0];
|
|
this._extensions[type] = (ext[0] !== '*') ? ext : ext.substr(1);
|
|
}
|
|
}
|
|
};
|
|
|
|
/**
|
|
* Lookup a mime type based on extension
|
|
*/
|
|
Mime.prototype.getType = function(path) {
|
|
path = String(path);
|
|
let last = path.replace(/^.*[/\\]/, '').toLowerCase();
|
|
let ext = last.replace(/^.*\./, '').toLowerCase();
|
|
|
|
let hasPath = last.length < path.length;
|
|
let hasDot = ext.length < last.length - 1;
|
|
|
|
return (hasDot || !hasPath) && this._types[ext] || null;
|
|
};
|
|
|
|
/**
|
|
* Return file extension associated with a mime type
|
|
*/
|
|
Mime.prototype.getExtension = function(type) {
|
|
type = /^\s*([^;\s]*)/.test(type) && RegExp.$1;
|
|
return type && this._extensions[type.toLowerCase()] || null;
|
|
};
|
|
|
|
module.exports = Mime;
|