如何从javascript中的输入文件中读取文本？

Question

I have a text file i want to read in my html page,both are in the same directory and i am not running a server. I intend that my users use the script offline(basically text manipulation based on expressions and preserving new line characters) .

1. I tried ajax call but mostly cross domain origin problem occured and i know most of the users will have this security tighened up in many browsers , so its not of use to circumvent this in only in my browser.

2. I want to support many browsers including old browsers as in IE7,8 etc which do not support HTML5 filereader.for the same reason reading using filesystemobject or activex is not good.

3. Reading the file after user select it as input , is this possible?Otherwise i would have no option then using other technologies like php,java etc which may expect my user to setup these.

Please excuse me if i am repeating this but i am a beginner web developer. I know that reading local files via javascript is not possible but is there any other way?

Answer 1

If you can't support FileReader, then the answer is pretty much no (at least, if you want to support a large range of browsers rather than rely on convenient feature x of browser y). Unless : you indeed increase the requirements for running the application and get some sort of local server going (for instance node.js, Apache, TomCat, etc. but like you said this will greatly increase the requirements and become cumbersome for users).

You could also rethink what it is you're trying to achieve. What are the contents of the file you want to read ? Can't these contents be part of the HTML file you're serving to your users (ie a large JSON Object inside a script-tag ?)

On possibility of using node.js:

Node.js is quite easy to install and assuming you are requiring from your users to install it, you can use it as a local server, which is a nodejs script of about two lines in size :). Running it locally would also omit the need to upload anything anywhere as you can directly read from the file system using the fs-object (see sitepoint.com/accessing-the-file-system-in-node-js).

STILL: from both a design and ease-of-use-point of view you might want to resort to using either another technology, or include the text file content inside the HMTL file