SailsJS（beta）图像中的船长在上传之前调整大小 [英] Skipper in SailsJS (beta) image resize before upload

问题描述

我正在使用SailsJS（测试版）。我试图找到一种方法来使用graphicsmagick在SailsJS-beta中使用Skipper解析的流来调整Skipper函数 req.file（'inputName'）之前调整图像的大小.upload（） 。

I'm using SailsJS (beta). I'm trying to find a way to use graphicsmagick to take the stream parsed by Skipper in SailsJS-beta to resize the image before calling the Skipper-function req.file('inputName').upload().

我的目标是拍摄原始图像，并在上传之前调整大小。 Sails beta引入了Skipper文件解析器，这些解析器文档很少（至少我不理解）。请帮助我了解如何在上传之前调整图片大小。

My goal is to take my large, original image, and resize it before uploading it. Sails beta have introduced the Skipper-file-parser which are poorly documented (at least I don't understand it). Please help me understand how to resize the image before upload.

这可行（我的控制器操作中的代码）：

This works (code in my controller action):

req.file('fileName').upload('storedImage.png', function(err, files){
  // File is now uploaded to storedImage.png
});

我想要的是：

// Read the file stream into a file upload
var stream = req.file('fileName');

gm(stream).resize(200, 200).write('storedImage.png', function(err){
  // File is now resized to 200x200 px and uploaded to storedImage.png
});

我的问题是：如何从 req.file中正确获取流（'fileName'）将它发送给gm？

My problem is: how do I properly fetch the stream from req.file('fileName') to send it to gm?

推荐答案

这应该适合你：

var Writable = require('stream').Writable;
var resize = require('image-resize-stream')(100); // Or any other resizer

// The output stream to pipe to
var output = require('fs').createWriteStream('storedImage.png');

// Let's create a custom receiver
var receiver = new Writable({objectMode: true});
receiver._write = function(file, enc, cb) {
  file.pipe(resize).pipe(output);

  cb();
};

现在你的行动中你必须使用你的接收器：

Now in your action you just have to use your receiver:

req.file('fileName').upload(receiver, function(err, files){
  // File is now resized to 100px width and uploaded to ./storedImage.png
});

我觉得Skipper的API会发生很大的变化，但现在可以使用了（使用v0.1.x）。

I have a feeling that Skipper's API is going to change, a lot, but this will work for now (with v0.1.x).

更新

具体来说，如果使用 gm 调整大小，它将是这样的：

Specifically, if using gm for resizing, it'll be something like this:

var gm = require('gm');
var Writable = require('stream').Writable;

// The output stream to pipe to
var output = require('fs').createWriteStream('storedImage.png');

// Let's create a custom receiver
var receiver = new Writable({objectMode: true});
receiver._write = function(file, enc, cb) {
  gm(file).resize('200', '200').stream().pipe(output);

  cb();
};

这篇关于SailsJS（beta）图像中的船长在上传之前调整大小的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！