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https://github.com/zxdong262/canvas-captcha
A simple captcha module for nodejs based on node-canvas
https://github.com/zxdong262/canvas-captcha
canvas canvas-captcha captcha
Last synced: about 2 months ago
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A simple captcha module for nodejs based on node-canvas
- Host: GitHub
- URL: https://github.com/zxdong262/canvas-captcha
- Owner: zxdong262
- Created: 2014-06-25T01:17:19.000Z (over 10 years ago)
- Default Branch: master
- Last Pushed: 2017-09-23T02:20:03.000Z (over 7 years ago)
- Last Synced: 2024-11-03T08:33:50.336Z (about 2 months ago)
- Topics: canvas, canvas-captcha, captcha
- Language: JavaScript
- Homepage:
- Size: 26.4 KB
- Stars: 32
- Watchers: 3
- Forks: 4
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
# canvas-captcha
[](https://travis-ci.org/zxdong262/canvas-captcha)
a captcha module for nodejs based on [node-canvas](https://www.npmjs.org/package/canvas)
## note
- install Cairo first, For system-specific installation view the Wiki from [node-canvas](https://www.npmjs.org/package/canvas)
- if you can see the captcha image, but empty, try another font your server has or install proper font pack in your server, such as `sudo apt-get install ttf-mscorefonts-installer`.
## Installation
```bash
npm install canvas-captcha
```
## use
```javascript
//captcha
let captcha = require('canvas-captcha')
let captchaOptions = {
charPool: ('abcdefghijklmnopqrstuvwxyz' + 'abcdefghijklmnopqrstuvwxyz'.toUpperCase() + '1234567890').split('') //char pool Array
,size: {
width: 100
,height: 32
} //image size
,textPos: {
left: 15
,top: 26
} //text drawing start position
,rotate: .01 //text ratate
,charLength: 4 //how many chars
,font: '26px Unifont' //font size
,strokeStyle: '#0088cc' //style
,bgColor: '#eeeeee' //bg color
,confusion: true //draw another group background text to mangle the text
,cFont: '30px Arial' //bg text style
,cStrokeStyle: '#adc' //bg text color
,cRotate: -.05 //bg text rotate
}
//callback style
app.get('/captcha', function(req, res) {
captcha(captchaOptions, function(err, data) {
if(err) {
res.send(err)
}
else {
req.session.captcha = data.captchaStr
res.end(data.captchaImg)
}
})
})
//use promise
let captchaPromise = function(options) {
return new Promise(function(resolve, reject) {
captcha(options, function(err, data) {
if(err) reject(err)
else resolve(data)
})
})
}
//in express
app.get('/captcha', function(req, res) {
captchaPromise(captchaOptions)
.then(function(data) {
req.session.captcha = data.captchaStr
res.end(data.captchaImg)
}, function(err) {
res.send(err)
})
})
//in koa
app.get('/captcha', function* (next) {
var data = yield captchaPromise(captchaOptions)
this.session.captcha = data.captchaStr
this.body = data.captchaImg
})
//or
app.get('/captcha', async ctx => {
let data = await captchaPromise(captchaOptions)
ctx.session.captcha = data.captchaStr
ctx.body = data.captchaImg
})
```
## test && example
```bash
git clone https://github.com/zxdong262/canvas-captcha.git
cd canvas-captcha
sudo npm install
# test
npm run test
# example
node test/app.js
# then visit http://127.0.0.1:5001
```
## changelog
- 2.1.0 use canvas 1.3.15, support node 6.2+
- 2.0.1 use canvas 1.3.12, a little rewrite
- 2.0.0 use canvas 1.2.9, compatible with nodejs v4
- 1.2.8 use 'Unifont' as default font
- 1.2.7 use 'system' as default font
- 1.2.6 just fix readme koa example
- 1.2.5 add some example to readme, use canvas version `1.2.1`
- 1.2.4 make `err` the first callback param
- 1.2.3 use canvas version `1.1.6` version instead of version `*`
## license
MIT