Trying to find a way to extract IPTC data from an image file buffer, there are existing libraries available on npm that allow you to open and read a file from the local filesystem but i am storing files on AWS S3 and would prefer to use buffers instead of creating unnecessary disk writes.
Not sure where to start, maybe start looking through how this module works:
https://www.npmjs.com/package/extract-iptc
And create my own module? Or is there an easier way that i've missed?
I was able to extract IPTC data by using
var iptc = require('node-iptc');
var iptc_data = iptc(imageData);
Also there's an isomorphic library exifr that works in both Node.js and browser. And it works with the new HEIC image format as well.
exifr.parse(input, {iptc: true}).then(output => {
console.log('IPTC', output)
})
It parses multiple formats (TIFF/EXIF, ICC, IPTC, XMP, JFIF) but IPTC isn't enabled by default so you need to enabled it in options as seen in the example.
Related
I'm coding a webpage that needs to read some data from different csv on a path depending on the country of the user.
the path is something like this:
./csv/m2-2022-10-25_13_45_55_es.csv
m2-2022-10-25_13_45_56_fr.csv
m2-2022-10-25_13_46_04_it.csv
etc
And those files will be replaced regularly, the only that we'll always have is the country code (es, fr, it, etc).
So, what I need is to list all the files on the path to an array, and loop through the array to find if the last characters of the filename are $countryCode + ".csv", and there run some code.
But I can't find how, all the solutions I find are using Node.js, but are there a solution using only Javascript (or jQuery)?
Regards!
You cannot use pure Javascript to do that, because if you wanted to search files in your computer only using javascript, it would be a huge security breach.
You must use node.js to open files but you can make an API to your nodejs file from your javascript and you can send as a response the content of your file.
Here some links that might help you :
FS : https://nodejs.org/api/fs.html
NodeJS api : https://medium.com/swlh/how-to-create-a-simple-restful-api-in-node-js-ae4bfddea158
You can check a similar question here:
Get list of filenames in folder with Javascript
You can't access to filesystem from the frontend, this it would be a huge security breach, because anyone could access to your filesystem tree.
You have to do a function in backend to build the array you want and send it to frontend.
If you create a function in backend file that returns the array of files in the folder, you can call it from the frontend via XMLHttpRequest or Fetch to get the array in frontend and be able to use in your js file.
I'm new to Excel Web Add-Ins and want to figure out if it's possible to make an add-in that can export a custom file.
I've looked around and all I find are Excel specific commands like Workbook.SaveAs() but I can't find anything on making custom export functions. I need to convert the file into XML but a specific XML setup and so, I could just work the data before I save it to XML. But again, can't find much of anything to suggest that this is supported.
How would I go about writing a file to disk from Excel that isn't just the Workbook?
There's no such API to support exporting custom file to disk. It seems we can have workaround to do this work, this workaround just works for excel online.
Please see this link:
How to create a file in memory for user to download, but not through server?
The closest thing there is for what you want to do is:
Office.context.document.getFileAsync(Office.FileType.Compressed, (result) => {
const file = result.value;
// do whatever ...
});
The file variable in this case contains the entire document in Office Open XML (OOXML) format as a byte array.
I have a very basic question: how can I read an image file in javascript and get access to its pixel data as arrays? I am writing a local script to be run as node myscript.js, so no need for any web-stuff.
Basically I need a javascript equivalent of the following python 2-liner, preferably with as few external dependencies as possible:
import skimage.io
image = skimage.io.imread('someimage.file',as_gray=False).astype('float64')
# do stuff to image
You can read a file/image using a FileReader() object in javascript.
From the documentation:
The FileReader object lets web applications asynchronously read the contents of files (or raw data buffers) stored on the user's computer, using File or Blob objects to specify the file or data to read.
And after reading an image, you can use a third-party library to manipulate it. Here are a few good libraries:
Caman JS
glfx.js
Grafi.js
Jimp
A basic example of reading file:
var fs = require('fs');
fs.readFile('image.jpg', function(err, data){
console.log(data);
});
I'm writing a backup script that will pull a full copy of every file in a specific blob container in our Windows Azure blob storage. These files are not uploaded by me, I'm just writing a script that traverses the blob storage and downloads the files.
To speed up this process and skip unnecessary downloads, I'd like to request MD5s for the files before downloading them, and compare them with the already local files.
My problem: I can't find documentation anywhere detailing how to do this. I'm pretty sure the API supports it, I'm finding docs and answered questions related to other languages everywhere, but not for the Node.js Azure SDK.
My question: Is it possible, and if yes, how, to request an MD5 for the remote file blob through the Azure Node.js SDK, before downloading it? And is it faster than just downloading the file?
It is certainly possible to get blob's MD5 hash. When you list blobs, you'll get MD5 in blob's properties. See the sample code below:
var azure = require('azure');
var blobService = azure.createBlobService("accountname", "accountkey");
blobService.listBlobs("containername", function(error, blobs){
if(!error){
for(var index in blobs){
console.log(blobs[index].name );
console.log(blobs[index].properties['content-md5'] );
}
}
});
Obviously the catch is that blob should have this property set. If this property is not set, then an empty string is returned.
I am new to HTML/Javascript, as well as coding in general so bear with me :). I am trying to create a "Spot the Difference" game in html5 using javascript. Everything is local (on my machine). I have two pictures, of the same size, one with differences. To generate data about the clickable fields, I have a java program that reads both of the images and outputs all of the positions in which pixels are different into a XML file. My plan was to then use this XML file with my javascript to define where the user could click. However, it appears (correct me if I'm wrong) that javascript cannot read local XML files for security reasons. I do not want to use an ActiveXObject because I plan on putting this onto mobile devices via phone gap or a webkit object. Does anyone have a better approach to this problem, or perhaps a way to read local XML files via javascript? Any help would be greatly appreciated, thanks.
If you are planning to put this into a smart phones (iOS and Android) and read local files, I have done similar things with JSON (yes, please don't use XML).
Convert your output to JSON
Put this as part of your application package. For example, in Android, I put it as part of the .apk in /appFiles/json
Create a custom content provider that would read the local file. I create mine as content:// but you create whatever scheme you want. You could leverage android.content.ContentProvider in order to achieve custom URL Scheme. iOS has its own way to create custom scheme as well. The implementation simply read your local storage and give the content
To read it from Javascript, I simply call ajax with the custom scheme to get the json file. For example content://myfile/theFile.json simply redirect me to particular directory in local storage with /myfile/theFile.json appended to it
Below is the sample to override openFile() in the ContentProvider
public ParcelFileDescriptor openFile (Uri uri, String mode) {
try {
Context c = getContext();
File cacheDir = c.getCacheDir();
String uriString = uri.toString();
String htmlFile = uriString.replaceAll(CUSTOM_CONTENT_URI, "");
// Translate the uri into pointer in the cache
File htmlResource = new File(cacheDir.toString() + File.separator + htmlFile);
File parentDir = htmlResource.getParentFile();
if(!parentDir.exists()) {
parentDir.mkdirs();
}
// get the file from one of the resources within the local storage
InputStream in = WebViewContentProvider.class.getResourceAsStream(htmlFile);
// copy the local storage to a cache file
copy(in, new FileOutputStream(htmlResource));
return ParcelFileDescriptor.open(htmlResource, ParcelFileDescriptor.MODE_READ_WRITE);
} catch(Exception e) {
throw new RuntimeException(e);
}
}
I hope it helps
I would suggest modifying your java program to output a JSON formatted file instead of XML. JSON is native to JavaScript and will be much simpler for you to load.
As for actually loading the data, i'm not sure what the best option is as you say you want to evenutally run this on a mobile device. If you were just making a normal website you could setup a web server using either Apache or IIS depending on your OS and put the files in the document root. Once you've done that you can load the JSON file via Ajax, which can easily be googled for.
Not sure if this helps any.
Since this is a local file, you can do this with jQuery
$.ajax({
type: "GET",
url: "your.xml",
dataType: "xml",
success: function(xml){
///do your thing
}
});
http://api.jquery.com/jQuery.ajax/