How to write Parse Cloud Code to make Thumbnails - parse-platform

Question

Assume I have a Table
---------Image-------------
imageFile (File) | thumbnail (File) | Post (a pointer to Post)
Any idea how to write a cloud code to take a smaller version of that image in another column?
For example, If a user uploaded a (2000x3500 px) image, Parse will save it in imageFile column, and save its thumbnail in the other column
thanks

Answer 1

Here's the current solution I'm using (Original script was published by Parse.com some time ago and deleted after the ownership transfer to the community):
Usage example in main.js:
var resizeImageKey = require('cloud/resize-image-key.js'),
THUMBNAIL_SIZE = 100,
Image = require("parse-image");
Parse.Cloud.afterSave("TableName", function(request) {
return resizeImageKey({
object: request.object, // ParseObject in which the thumbnail will be saved
url: objectImage.url(), // Full size image URL
toKey: "thumbnail", // thumbnail's attribute key
width: THUMBNAIL_SIZE, // width
crop: false // resize or crop ?
});
});
resize-image-key.js (async-await)
const Image = require("parse-image");
/*
Original: https://github.com/ParsePlatform/Anyimg/blob/master/parse/cloud/resize-image-key.js
Resizes an image from one Parse Object key containing
a Parse File to a file object at a new key with a target width.
If the image is smaller than the target width, then it is simply
copied unaltered.
object: Parse Object
url: URL of the Parse File
toKey: Key to contain the target Parse File
width: Target width
crop: Center crop the square
*/
module.exports = function(options) {
let format, originalHeight, originalWidth, newHeight, newWidth;
// First get the image data
const response = await Parse.Cloud.httpRequest({
//url: options.object.get(options.fromKey).url()
url: options.url
})
let image = new Image();
await image.setData(response.buffer);
// set some metadata that will be on the object
format = image.format();
originalHeight = image.height();
originalWidth = image.width();
if (image.width() <= options.width) {
// No need to resize
// Remove from code
} else {
var newWidth = options.width;
var newHeight = options.width * image.height() / image.width();
// If we're cropping to a square, then we need to adjust height and
// width so that the greater length of the two fits the square
if (options.crop && (newWidth > newHeight)) {
var newHeight = options.width;
var newWidth = newHeight * image.width() / image.height();
}
// resize down to normal width size
image = await image.scale({
width: newWidth,
height: newHeight
});
}
// crop ?
if (options.crop) {
let left = 0;
let top = 0;
// Center crop
if (image.width() > image.height()) {
left = (image.width() - image.height()) / 2;
} else {
top = (image.height() - image.width()) / 2;
}
image = await image.crop({
left: left,
top: top,
width: options.width,
height: options.width
});
}
newHeight = image.height();
newWidth = image.width();
// Get the image data in a Buffer.
const buffer = await image.data();
// Save the image into a new file.
const base64 = buffer.toString("base64");
//var scaled = new Parse.File("thumbnail_" + options.object.get("name") + "." + format, {
const scaled = new Parse.File("thumbnail." + format, {
base64: base64
});
const savedImage = await scaled.save();
// Set metadata on the image object
options.object.set(options.toKey, savedImage);
//return options.object.save();
options.object.set("thumbnail_width", newWidth);
options.object.set("thumbnail_height", newHeight);
};
resize-image-key.js (vanilla JS)
var Image = require("parse-image");
/*
Original: https://github.com/ParsePlatform/Anyimg/blob/master/parse/cloud/resize-image-key.js
Resizes an image from one Parse Object key containing
a Parse File to a file object at a new key with a target width.
If the image is smaller than the target width, then it is simply
copied unaltered.
object: Parse Object
url: URL of the Parse File
toKey: Key to contain the target Parse File
width: Target width
crop: Center crop the square
*/
module.exports = function(options) {
var format, originalHeight, originalWidth, newHeight, newWidth;
// First get the image data
return Parse.Cloud.httpRequest({
//url: options.object.get(options.fromKey).url()
url: options.url
}).then(function(response) {
var image = new Image();
return image.setData(response.buffer);
}).then(function(image) {
// set some metadata that will be on the object
format = image.format();
originalHeight = image.height();
originalWidth = image.width();
if (image.width() <= options.width) {
// No need to resize
return new Parse.Promise.as(image);
} else {
var newWidth = options.width;
var newHeight = options.width * image.height() / image.width();
// If we're cropping to a square, then we need to adjust height and
// width so that the greater length of the two fits the square
if (options.crop && (newWidth > newHeight)) {
var newHeight = options.width;
var newWidth = newHeight * image.width() / image.height();
}
// resize down to normal width size
return image.scale({
width: newWidth,
height: newHeight
});
}
}).then(function(image) {
if (options.crop) {
var left = 0;
var top = 0;
// Center crop
if (image.width() > image.height()) {
var left = (image.width() - image.height()) / 2;
} else {
var top = (image.height() - image.width()) / 2;
}
return image.crop({
left: left,
top: top,
width: options.width,
height: options.width
});
} else {
return Parse.Promise.as(image);
}
}).then(function(image) {
newHeight = image.height();
newWidth = image.width();
// Get the image data in a Buffer.
return image.data();
}).then(function(buffer) {
// Save the image into a new file.
var base64 = buffer.toString("base64");
//var scaled = new Parse.File("thumbnail_" + options.object.get("name") + "." + format, {
var scaled = new Parse.File("thumbnail." + format, {
base64: base64
});
return scaled.save();
}).then(function(image) {
// Set metadata on the image object
options.object.set(options.toKey, image);
//return options.object.save();
options.object.set("thumbnail_width", newWidth);
options.object.set("thumbnail_height", newHeight);
});
};
Update: Found a clone of the original script and archived it just in case: https://web.archive.org/web/20190107225015/https://github.com/eknight7/Anyimg/blob/master/parse/cloud/resize-image-key.js