I have the following file structure:
test.html
test.json
And the following JS function:
function get_file(){
var app_path = app.activeDocument.path,
file = new File(app_path + '/test.json');
console.log(file);
}
How can I make the function log the file's content?
I'm not sure if everything you can do in the browsers environment translates to everything you can do in photoshops environment. But you should look at a few things.
Doing This in the Browser
The File object.
https://developer.mozilla.org/en-US/docs/Web/API/File
Notable that it extends the Blob object.
https://developer.mozilla.org/en-US/docs/Web/API/Blob
Which if you researched you would find it can be read using the FileReader.
https://developer.mozilla.org/en-US/docs/Web/API/FileReader
So this would work in the browser but may/may-not work in the photoshop scripting set.
function get_file(){
var app_path = app.activeDocument.path,
file = new File(app_path + '/test.json');
var reader = new FileReader();
reader.onloadend = function() {
console.log(reader.result);
}
reader.readAsText(file);
}
This is asynchronous so you may need to use a callback depending on what you're trying to do with this. You won't be able to return the string from inside the reader.onloadend event.
Doing This in Photoshop
Take a look at their scripting references. Specifically the javascript reference.
All Resources: http://www.adobe.com/devnet/photoshop/scripting.html
Javascript PDF: http://wwwimages.adobe.com/content/dam/Adobe/en/devnet/photoshop/pdfs/photoshop-cc-javascript-ref-2015.pdf
It looks like they don't have the FileReader but instead the File object can be used to read content. The File API begins on page 109 but it's empty! The documentation is a bit pathetic so I can see why you'd have trouble finding this. With some searching I found someone doing this in 2012 (but I don't know if it will still work- worth a shot)
var b = new File("c:\test.txt");
b.open('r');
var str = "";
while(!b.eof) {
str += b.readln();
}
b.close();
alert(str);
Let me know if that works.
Related
I'm just trying on the task, file manipulation system using java script. As I was referred from W3C File API( https://www.w3.org/TR/FileAPI/ ), we can only read local files like
var file = "test.txt";
function readTextFile(file) {
var readFile;
if(window.XMLHttpRequest){
// for new browsers
readFile = new XMLHttpRequest();
}else{
//for old browsers like IE5 or IE6
readFile = new ActiveXObject("Microsoft.XMLHTTP");
}
readFile.open("GET", file, true);
readFile.onreadystatechange = function() {
if(readFile.readyState === 4) {
if(readFile.status === 200 || readFile.status == 0) {
//text will be displayed that read from the file
console.log(readFile.responseText);
}
}
}
readFile.send(null);
}
but it looks there is no options to write on file without server. I was tried to fetch solutions from the websites like http://www.stackoverflow.com/, the study says almost there is no possibilities.
For an example what I got is
from https://gist.github.com/Arahnoid/9925725
It shows error "TypeError: file.open is not a function."
So my question is, Is there any possible to file manipulations(asking only about Write file) for local files without using server-side scripting or is any extensions like available?
We can do file manipulations using server scripting languages such as PHP, Node.js.
Thanks in advance.
In your code, it's not reading from the local file (test.txt), it's sending Ajax GET request to server and read file in server side.
To read local file (files that stored in machine where browser is installed), you need to use FileAPI, which is not used in current code.
To write file to local, it's impossible to write it directly using JavaScript. Otherwise, it would be a huge security vulnerability. However, you can generate a URL from File object, and use that URL as the href attribute of <a> tag, so that user can download and "write to local" manually.
Here is a code snippet to read & "write" local file:
var inputElement = document.getElementById("input");
var reader = new FileReader();
var downloadLink = document.getElementById('downloadLink');
reader.onloadend = function(){
console.log(reader.result);
}
inputElement.addEventListener("change", handleFiles, false);
function handleFiles() {
var fileSelected = this.files[0]; /* now you can work with the file list */
reader.readAsBinaryString(fileSelected);
downloadLink.href = window.URL.createObjectURL(fileSelected);
}
<input type="file" id="input">
<a id="downloadLink" download>Download</a>
I"m a noob in javascript so I am sorry if my question is a simple one. anyway,
I'm writing a code that creates a batch file in order to open a certain file in the default application defined by the operation system. For example, pdf files will open in Adobe's Acrobat Reader. To do so, I'm using the FileSaver.js
And my code goes like this:
$(document).ready(function() {
$('#openPdf').click(function() {
saveAs(data2blob(
myPDF),
'openPDF.bat');
});
});
function data2blob(data, isBase64) {
var chars = "";
if (isBase64)
chars = atob(data);
else
chars = data;
var bytes = new Array(chars.length);
for (var i = 0; i < chars.length; i++)
bytes[i] = chars.charCodeAt(i);
var blob = new Blob([new Uint8Array(bytes)],
{type: "text/plain;charset=utf-8"});
return blob;
}
with myPDF being a string to a specific file I want to open which I'm certain of its existence. When I test my code on IE, it works perfectly. However, when I try it on Firefox, the file created is 'openPDF.bat.sdx' instead of 'openPDF.bat'. I've checked that it is indeed the same file only with the added extension. Does anyone have an idea what is the reason for this? and how can I overcome it?
I finally managed to download the file in Firefox the same way as in IE. I've made one minor change in the code: when creating the blob variable in the data2blob function I've used:
var blob = new Blob([new Uint8Array(bytes)], {type: "application/octet-stream"});
Not sure, what is the difference between the way it was before and how it is now, except of the result of course.
Based on research, I've found tutorials, such as this one from Eric Bidelman, that go into FileReader usage. Instead of local files, these tutorials use files provided by the user. Modifying these examples to try and display local files were not successful.
After some research I've found that most browsers by default do not allow access to local files [1]. Some recommend using unsafe modes for testing, but that's not what I'm looking for as that would apply to only my testing [2].
Currently I allow the download of log files. My goal here with FileReader was to provide a way to view the files as well. Is there a way to achieve this? I'm coming up with blanks and have almost resigned to only allowing downloads instead of adding viewing. The following is example code of local file reading. This code fails since 'logpath' is not of type blob. I believe my question doesn't really require code, but I provided an example anyway.
HTML Code
<select name="loglist" id="loglist" onchange="run()" size="2">
<option>stack1.log</option>
<option>stack2.log</option>
</select>
Javascript
function run() {
var reader = new FileReader();
log = document.getElementById( "loglist" ).value;
var logdir = "/var/log/";
var logpath = logdir.concat(log);
reader.onload = function() {
logtext = reader.result;
alert(logtext);
}
reader.readAsText(logpath);
}
There is no way for JavaScript, embedded in a webpage, to access files on the user's local system other than through the File API when the user selects the file using a file input. It is not possible for the page to supply the file name to be opened.
var inp = document.querySelector("input");
inp.addEventListener("change", show);
function show(e) {
var f = this.files[0];
var r = new FileReader();
r.addEventListener("load", display);
r.readAsText(f);
function display(e) {
document.body.appendChild(
document.createTextNode(
e.target.result
)
);
}
}
<input type="file" id="input">
I do NOT want to read the ENTIRE contents of a file into memory; only parts of it, and only on demand.
Yet, It seems I can read a chunk ONLY ONCE (using a file.slice()), while all following reads return zero-length. Any ideas?
Here is a simplified sample of the code that fails on 2nd call:
var chunkNo=0;
function readNextChunk()
{
var file=document.getElementsByTagName("input").item(0).files[0];
var blob=file.slice(100*chunkNo, 100);
var reader=new FileReader();
reader.onload=function(e) { console.log("No"+chunkNo+":\n"+reader.result);
chunkNo++;
};
reader.readAsText(blob);
}
I want to read a file (on the client side) and get the content in an array. It will be just one file. I have the following and it doesn't work. 'query_list' is a textarea where I want to display the content of the file.
<input type="file" id="file" name="file" enctype="multipart/form-data"/>
<script>
document.getElementById('file').addEventListener('change', readFile, false);
function readFile (evt) {
var files = evt.target.files;
var file = files[0];
var fh = fopen(file, 0);
var str = "";
document.getElementById('query_list').textContent = str;
if(fh!=-1) {
length = flength(fh);
str = fread(fh, length);
fclose(fh);
}
document.getElementById('query_list').textContent = str;
}
</script>
How should I go about it? Eventually I want to loop over the array and run some SQL queries.
If you want to read files on the client using HTML5's FileReader, you must use Firefox, Chrome or IE 10+. If that is true, the following example reads a text file on the client.
your example attempts to use fopen that I have never heard of (on the client)
http://jsfiddle.net/k3j48zmt/
document.getElementById('file').addEventListener('change', readFile, false);
function readFile (evt) {
var files = evt.target.files;
var file = files[0];
var reader = new FileReader();
reader.onload = function(event) {
console.log(event.target.result);
}
reader.readAsText(file)
}
For IE<10 support you need to look into using an ActiveX Object like ADO.Stream Scripting.FileSystemObject http://msdn.microsoft.com/en-us/library/2z9ffy99(v=vs.85).aspx but you'll run into a security problem. If you run IE allowing all ActiveX objects (for your website), it should work.
There is such thing as HTML5 File API to access local files picked by user, without uploading them anywhere.
It is quite new feature, but supported by most of modern browsers.
I strongly recommend to check out this great article to see, how you can use it.
There is one problem with this, you can't read big files (~400 MB and larger) because straight forward FileAPI functions attempting to load entire file into memory.
If you need to read big files, or search something there, or navigate by line index check my LineNavigator, which allows you to read, navigate and search in files of any size. Try it in jsFiddle! It is super easy to use:
var navigator = new FileNavigator(file);
navigator.readSomeLines(0, function linesReadHandler(err, index, lines, eof, progress) {
// Some error
if (err) return;
// Process this line bucket
for (var i = 0; i < lines.length; i++) {
var line = lines[i];
// Do something with it
}
// End of file
if (eof) return;
// Continue reading
navigator.readSomeLines(index + lines.length, linesReadHandler);
});
Well I got beat to the answer but its different:
<input type="file" id="fi" />
<button onclick="handleFile(); return false;">click</button>
function handleFile() {
var preview = document.getElementById('prv')
var file = document.getElementById('fi').files[0];
var div = document.body.appendChild(document.createElement("div"));
div.innerHTML = file.getAsText("utf-8");
}
This will work in FF 3.5 - 3.6, and that's it. FF 4 and WebKit you need to use the FileReader as mentioned by Juan Mendes.
For IE you may find a Flash solution.
I work there, but still wanted to contribute because it works well: You can use the filepicker.io read api to do exactly this. You can pass in an dom element and get the contents back, for text or binary data, even in IE8+