javascript - 如何从 Meteor 中的文件夹中读取所有 JSON 文件？

Question

我想在我的 Meteor 应用程序中读取文件夹内的所有 json 文件。

我有以下结构:

/server  
-- /methods  
-- -- file1.json  
-- -- file2.json  

我尝试使用以下代码读取所有 JSON 文件:

var fs = Npm.require('fs');
var path = Npm.require('path');
var base = path.resolve('.');

try {
    var files = fs.readdirSync(base + '/methods/*.json');
    console.log(files);
} catch (e) {
    console.dir(e)
}

但这不起作用，它向我显示一个错误，指出该目录或文件不存在。

我是不是犯了什么错误？或者还有其他方法吗？

Answer 1

首先，请小心寻找 Meteor 的项目根目录，因为 path.resolve('.') 甚至 process.env.PWD 的结果可能改变不同的部署设置。

其次，fs.readdirSync(path) 的参数path需要一个目录。因此，正确的调用应该是 var files = fs.readdirSync(base + '/server/methods/');。

但是，我建议使用 Assets .只需将您的 JSON 文件移动到您的 private 目录，然后通过 Assets.getText(assetPath, [asyncCallback]) 在服务器上访问它们或 Assets.getBinary(assetPath, [asyncCallback]) .

例如:

if (Meteor.isServer) {
    Meteor.startup(function() {
        var example1 = JSON.parse(Assets.getText('methods/example1.json'));
        var example2 = JSON.parse(Assets.getText('methods/example2.json'));
        console.log(example1);
        console.log(example2);
    });
}

如果您想读取所有 JSON 文件，您可能需要以下解决方法:

if (Meteor.isServer) {
    Meteor.startup(function() {
        var exec = Npm.require('child_process').exec;
        var files = [],
            fileNames = [];
        exec('ls -m assets/app/methods | tr -d \' \n\' ', Meteor.bindEnvironment(function(error, stdout, stderr) {
            if (error !== null) {
                console.log('exec error: ' + error);
            }
            fileNames = stdout.split(',');
            /* Print all file names. */
            console.log("File names:");
            console.log(fileNames);
            _.each(fileNames, function(fileName) {
                /* Check if file has proper extension. */
                if (fileName.split('.').pop() == 'json') files.push(JSON.parse(Assets.getText('methods/' + fileName)));
            });
            /* Print all JSON files. */
            _.each(files, function(file) {
                console.log(file);
            });
        }));
    });
}

如果你想同步调用exec，你可能需要使用Meteor.wrapAsync(func, [context]) :

if (Meteor.isServer) {
    var exec = Npm.require('child_process').exec;
    var files = [], fileNames = [];

    var execAsync = function (options, callback) {
        console.log("execAsync()");
        exec('ls -m assets/app/methods | tr -d \' \n\' ', Meteor.bindEnvironment(function (error, stdout, stderr) {
            if (error !== null) {
                console.log('exec error: ' + error);
            }
            fileNames = stdout.split(',');
            /* Print all file names. */
            console.log("File names:");
            console.log(fileNames);
            _.each(fileNames, function (fileName) {
                /* Check if file has proper extension. */
                if (fileName.split('.').pop() == 'json') files.push(JSON.parse(Assets.getText('methods/' + fileName)));
            });
            callback(null, options.callback);
        }));
    };

    function postProcessing(callback) {
        console.log("postProcessing()");
        /* Print all JSON files. */
        _.each(files, function (file) {
            console.log(file);
        });
        callback();
    }

    Meteor.startup(function () {
        /*  Wrap asynchronous exec function, in order to call it in a synchronous style. */
        var execSync = Meteor.wrapAsync(execAsync);
        var refToPostProcessing = execSync({callback: postProcessing});
        var postProcessingSync = Meteor.wrapAsync(refToPostProcessing);
        postProcessingSync();
    });

}

这是我的服务器输出:

I20150919-09:27:09.189(2)? execAsync()        
I20150919-09:27:09.210(2)? File names:
I20150919-09:27:09.213(2)? [ 'example1.json', 'example2.json' ]
I20150919-09:27:09.215(2)? postProcessing()
I20150919-09:27:09.217(2)? { name: 'Product',
I20150919-09:27:09.217(2)?   properties: 
I20150919-09:27:09.218(2)?    { id: 
I20150919-09:27:09.218(2)?       { type: 'number',
I20150919-09:27:09.218(2)?         description: 'Product identifier',
I20150919-09:27:09.218(2)?         required: true },
I20150919-09:27:09.218(2)?      name: 
I20150919-09:27:09.218(2)?       { description: 'Name of the product',
I20150919-09:27:09.219(2)?         type: 'string',
I20150919-09:27:09.219(2)?         required: true },
I20150919-09:27:09.219(2)?      price: { type: 'number', minimum: 0, required: true },
I20150919-09:27:09.219(2)?      tags: { type: 'array', items: [Object] } } }
I20150919-09:27:09.220(2)? { red: '#f00',
I20150919-09:27:09.221(2)?   green: '#0f0',
I20150919-09:27:09.221(2)?   blue: '#00f',
I20150919-09:27:09.221(2)?   cyan: '#0ff',
I20150919-09:27:09.221(2)?   magenta: '#f0f',
I20150919-09:27:09.221(2)?   yellow: '#ff0',
I20150919-09:27:09.221(2)?   black: '#000' }

假设您有以下结构:

your-meteor-project
├── .meteor
├── server
├── private
│   └── methods
│       └── example1.json
│       └── example2.json
└── …