xpath-builder

xpath-builder

A JavaScript DSL around a subset of XPath 1.0. Its primary purpose is to facilitate writing complex XPath queries from JavaScript code.

xpath-builder is a port of the xpath Ruby gem.

Generating expressions

To create quick, one-off expressions, create an xpath builder:

x = require('xpath-builder').dsl();

x.descendant('ul').where(x.attr('id').equals('foo'))

However for more complex expressions, it is probably more convenient to include the builder object in your prototype chain:

function MyXPaths() {}

MyXPaths.prototype = require('xpath-builder').dsl();

MyXPaths.prototype.fooList = function() {
  return this.descendant('ul').where(this.attr('id').equals('foo'));
};

MyXPaths.prototype.passwordField = function(id) {
  return this.descendant('input')
             .where(this.attr('type').equals('password'))
             .where(this.attr('id').equals(id));
};

Both ways return an Expression instance, which can be further modified. To convert the expression to a string, just call .toString() on it. All available expressions are defined in DSL.

Strings and Literals

When you send a string as an argument to any xpath-builder function, it may be interepreted as a string literal, or an xpath literal, depending on the function:

x.descendant('p').where(x.attr('id').equals('foo'))

Which generates:

.//p[./@id = 'foo']

Occasionally you might want XPath literals instead of string literals, in which case wrap your string in a call to .literal():

x.descendant('p').where(x.attr('id').equals(x.literal('foo')))

Which generates:

.//p[./@id = foo]

This expression would match any p tag whose id attribute matches a 'foo' tag it contains. Most of the time, this is not what you want.

License

(The MIT License)

Copyright © 2013 Josh Chisholm

Copyright © 2010 Jonas Nicklas

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the ‘Software’), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED ‘AS IS’, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.