我在ExpressJS中构建了一个将文档导出为HTML页面的方法：
html: function (req, res) {
Project.findOne( { req.params.project },
function (err, project) {
res.contentType('text/html');
res.render('exporting/html', { project.name });
}
);
},
此外，我想创建一个方法，在ZIP存档中包含生成的HTML页面以及一些静态资源。
这是我目前的代码：
zip: function (req, res) {
Project.findOne( { req.params.project },
function (err, project) {
res.contentType('application/zip');
res.setHeader('content-disposition', 'attachment; filename=' + project.name + '.zip');
var zip = new AdmZip();
zip.addFile("readme.txt", new Buffer("This was inside the ZIP!"));
//------ Here I'd like to use zip.addFile to include the HTML output from the html method above ------
res.send(zip.toBuffer());
}
);
}
如何使zip方法包含html方法的输出？
答案 0 :(得分：1)
您有两种选择：一种相对简单，另一种更复杂。你必须决定你认为哪个是哪个。 ;）
因为你依赖快递＆＃39; Response.render从视图创建HTML，您需要在服务器上调用该路由以检索页面内容，以便将其包含在您的zip响应中。
假设您在此文件中的某处var http=require('http');，您可以：
zip: function (req, res) {
var projectId=req.params.project||'';
if(!projectId){ // make sure we have what we need!
return res.status(404).send('requires a projectId');
}
// Ok, we start by requesting our project...
Project.findOne({id:projectId},function(err, project) {
if(err) { // ALWAYS handle errors!
return res.status(500).send(err);
}
if('object'!==typeof project){ // did we get what we expected?
return res.status(404).send('failed to find project for id: '+projectId);
}
var projectName=project.name || ''; // Make no assumptions!
if(!projectName){
return res.status(500).send('whoops! project has no name!');
}
// For clarity, let's write a function to create our
// zip archive which will take:
// 1. a name for the zip file as it is sent to the requester
// 2. an array of {name:'foo.txt',content:''} objs, and
// 3. a callback which will send the result back to our
// original requester.
var createZipArchive=function(name, files, cb){
// create our zip...
var zip=new AdmZip();
// add the files to the zip
if(Array.isArray(files)){
files.forEach(function(file){
zip.addFile(file.name,new Buffer(file.content));
});
}
// pass the filename and the new zip to the callback
return cb(name, zip);
};
// And the callback that will send our response...
//
// Note that `res` as used here is the original response
// object that was handed to our `zip` route handler.
var sendResult=function(name, zip){
res.contentType('application/zip');
res.setHeader('content-disposition','attachment; filename=' + name);
return res.send(zip.toBuffer());
};
// Ok, before we formulate our response, we'll need to get the
// html content from ourselves which we can do by making
// a get request with the proper url.
//
// Assuming this server is running on localhost:80, we can
// use this url. If this is not the case, modify it as needed.
var url='http://localhost:80/html';
var httpGetRequest = http.get(url,function(getRes){
var body=''; // we'll build up the result from our request here.
// The 'data' event is fired each time the "remote" server
// returns a part of its response. Remember that these data
// can come in multiple chunks, and you do not know how many,
// so let's collect them all into our body var.
getRes.on('data',function(chunk){
body+=chunk.toString(); // make sure it's not a Buffer!
});
// The 'end' event will be fired when there are no more data
// to be read from the response so it's here we can respond
// to our original request.
getRes.on('end',function(){
var filename=projectName+'.zip',
files=[
{
name:'readme.txt',
content:'This was inside the ZIP!'
},{
name:'result.html',
content:body
}
];
// Finally, call our zip creator passing our result sender...
//
// Note that we could have both built the zip and sent the
// result here, but using the handlers we defined above
// makes the code a little cleaner and easier to understand.
//
// It might have been nicer to create handlers for all the
// functions herein defined in-line...
return createZipArchive(filename,files,sendResult);
});
}).on('error',function(err){
// This handler will be called if the http.get request fails
// in which case, we simply respond with a server error.
return res.status(500).send('could not retrieve html: '+err);
});
);
}
这是解决问题的最佳方法，即使它看起来很复杂。使用更好的方法可以减少一些复杂性 像superagent这样的HTTP客户端库将所有事件处理工具简化为简单：
var request = require('superagent');
request.get(url, function(err, res){
...
var zip=new AdmZip();
zip.addFile('filename',new Buffer(res.text));
...
});
第二种方法使用render()表达方式＆＃39; app对象，这正是res.render()用于将视图转换为HTML的用途。
请参阅Express app.render()了解此功能的运作方式。
请注意，除了从// - NEW CODE HERE -开始注释的部分之外，此解决方案是相同的。
zip: function (req, res) {
var projectId=req.params.project||'';
if(!projectId){ // make sure we have what we need!
return res.status(404).send('requires a projectId');
}
// Ok, we start by requesting our project...
Project.findOne({id:projectId},function(err, project) {
if(err) { // ALWAYS handle errors!
return res.status(500).send(err);
}
if('object'!==typeof project){ // did we get what we expected?
return res.status(404).send('failed to find project for id: '+projectId);
}
var projectName=project.name || ''; // Make no assumptions!
if(!projectName){
return res.status(500).send('whoops! project has no name!');
}
// For clarity, let's write a function to create our
// zip archive which will take:
// 1. a name for the zip file as it is sent to the requester
// 2. an array of {name:'foo.txt',content:''} objs, and
// 3. a callback which will send the result back to our
// original requester.
var createZipArchive=function(name, files, cb){
// create our zip...
var zip=new AdmZip();
// add the files to the zip
if(Array.isArray(files)){
files.forEach(function(file){
zip.addFile(file.name,new Buffer(file.content));
});
}
// pass the filename and the new zip to the callback
return cb(name, zip);
};
// And the callback that will send our response...
//
// Note that `res` as used here is the original response
// object that was handed to our `zip` route handler.
var sendResult=function(name, zip){
res.contentType('application/zip');
res.setHeader('content-disposition','attachment; filename=' + name);
return res.send(zip.toBuffer());
};
// - NEW CODE HERE -
// Render our view, build our zip and send our response...
app.render('exporting/html', { name:projectName }, function(err,html){
if(err){
return res.status(500).send('failed to render view: '+err);
}
var filename=projectName+'.zip',
files=[
{
name:'readme.txt',
content:'This was inside the ZIP!'
},{
name:'result.html',
content:html
}
];
// Finally, call our zip creator passing our result sender...
//
// Note that we could have both built the zip and sent the
// result here, but using the handlers we defined above
// makes the code a little cleaner and easier to understand.
//
// It might have been nicer to create handlers for all the
// functions herein defined in-line...
return createZipArchive(filename,files,sendResult);
});
}
虽然这种方法稍微短一些，但通过利用Express用于呈现视图的底层机制，它可以“耦合”＃34;您的zip路由到Express引擎的方式是，如果Express API将来发生变化，您需要对服务器代码进行两次更改（以正确处理html路由和zip路由），而不是只使用前一个解决方案。
就个人而言，我赞成第一个解决方案，因为它更清洁（在我看来）并且更加独立于意外的变化。但正如他们所说YMMV;）。