116 lines
3.8 KiB
Markdown
116 lines
3.8 KiB
Markdown
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# node-expat
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[](https://travis-ci.org/astro/node-expat/branches)
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[](http://standardjs.com/)
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## Motivation
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You use [Node.js](https://nodejs.org) for speed? You process XML streams? Then you want the fastest XML parser: [libexpat](http://expat.sourceforge.net/)!
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## Install
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```
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npm install node-expat
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```
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## Usage
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Important events emitted by a parser:
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```javascript
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(function () {
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"use strict";
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var expat = require('node-expat')
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var parser = new expat.Parser('UTF-8')
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parser.on('startElement', function (name, attrs) {
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console.log(name, attrs)
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})
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parser.on('endElement', function (name) {
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console.log(name)
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})
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parser.on('text', function (text) {
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console.log(text)
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})
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parser.on('error', function (error) {
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console.error(error)
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})
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parser.write('<html><head><title>Hello World</title></head><body><p>Foobar</p></body></html>')
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}())
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```
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## API
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* `#on('startElement' function (name, attrs) {})`
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* `#on('endElement' function (name) {})`
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* `#on('text' function (text) {})`
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* `#on('processingInstruction', function (target, data) {})`
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* `#on('comment', function (s) {})`
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* `#on('xmlDecl', function (version, encoding, standalone) {})`
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* `#on('startCdata', function () {})`
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* `#on('endCdata', function () {})`
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* `#on('entityDecl', function (entityName, isParameterEntity, value, base, systemId, publicId, notationName) {})`
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* `#on('error', function (e) {})`
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* `#stop()` pauses
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* `#resume()` resumes
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## Error handling
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We don't emit an error event because libexpat doesn't use a callback
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either. Instead, check that `parse()` returns `true`. A descriptive
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string can be obtained via `getError()` to provide user feedback.
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Alternatively, use the Parser like a node Stream. `write()` will emit
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error events.
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## Namespace handling
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A word about special parsing of *xmlns:* this is not necessary in a
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bare SAX parser like this, given that the DOM replacement you are
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using (if any) is not relevant to the parser.
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## Benchmark
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`npm run benchmark`
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| module | ops/sec | native | XML compliant | stream |
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|---------------------------------------------------------------------------------------|--------:|:------:|:-------------:|:--------------:|
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| [sax-js](https://github.com/isaacs/sax-js) | 99,412 | ☐ | ☑ | ☑ |
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| [node-xml](https://github.com/dylang/node-xml) | 130,631 | ☐ | ☑ | ☑ |
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| [libxmljs](https://github.com/polotek/libxmljs) | 276,136 | ☑ | ☑ | ☐ |
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| **node-expat** | 322,769 | ☑ | ☑ | ☑ |
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Higher is better.
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## Testing
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```
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npm install -g standard
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npm test
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```
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## Windows
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If you fail to install node-expat as a dependency of node-xmpp, please update node-xmpp as it doesn't use node-expat anymore.
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Dependencies for `node-gyp` https://github.com/TooTallNate/node-gyp#installation
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See https://github.com/astro/node-expat/issues/78 if you are getting errors about not finding `nan.h`.
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### expat.vcproj
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```
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VCBUILD : error : project file 'node-expat\build\deps\libexpat\expat.vcproj' was not found or not a valid proj
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ect file. [C:\Users\admin\AppData\Roaming\npm\node_modules\node-expat\build\bin
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ding.sln]
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```
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Install [Visual Studio C++ 2012](http://go.microsoft.com/?linkid=9816758) and run npm with the [`--msvs_version=2012` flag](http://stackoverflow.com/a/16854333/937891).
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