Trello API add base64 data image as an attachement - api

Question

I'd like to send base64 image as an attachment to a trello card through the API
POST /1/cards/[card id or shortlink]/attachments
There's a file field but it does not specify how should look the data there.
Refs: https://developers.trello.com/advanced-reference/card#post-1-cards-card-id-or-shortlink-attachments
Any idea?

Answer 1

Short answer: Trello's API only works to attach binary data via multipart/form-data. Examples below.
Long answer:
The Trello API to add attachments and images is frustratingly under-documented. They do have a coffeescript Client.js for those of us using Javascript to simplify all the basic operations: https://trello.com/1/client.coffee
Using the vanilla Client.js file I have been able to attach links and text files. While the CURL example shows pulling a binary file in from a hard drive, that doesn't work for those of us completely on a server or client where we don't have permissions to create a file.
From a LOT of trial and error, I've determined all binary data (images, documents, etc.) must be attached using multipart/form-data. Here is a jQuery snippet that will take a URL to an item, get it into memory, and then send it to Trello.
var opts = {'key': 'YOUR TRELLO KEY', 'token': 'YOUR TRELLO TOKEN'};
var xhr = new XMLHttpRequest();
xhr.open('get', params); // params is a URL to a file to grab
xhr.responseType = 'blob'; // Use blob to get the file's mimetype
xhr.onload = function() {
var fileReader = new FileReader();
fileReader.onload = function() {
var filename = (params.split('/').pop().split('#')[0].split('?')[0]) || params || '?'; // Removes # or ? after filename
var file = new File([this.result], filename);
var form = new FormData(); // this is the formdata Trello needs
form.append("file", file);
$.each(['key', 'token'], function(iter, item) {
form.append(item, opts.data[item] || 'ERROR! Missing "' + item + '"');
});
$.extend(opts, {
method: "POST",
data: form,
cache: false,
contentType: false,
processData: false
});
return $.ajax(opts);
};
fileReader.readAsArrayBuffer(xhr.response); // Use filereader on blob to get content
};
xhr.send();
I have submitted a new coffeescript for Trello developer support to consider uploading to replace Client.js. It adds a "Trello.upload(url)" that does this work.
I've also attached here for convenience in JS form.
// Generated by CoffeeScript 1.12.4
(function() {
var opts={"version":1,"apiEndpoint":"https://api.trello.com","authEndpoint":"https://trello.com"};
var deferred, isFunction, isReady, ready, waitUntil, wrapper,
slice = [].slice;
wrapper = function(window, jQuery, opts) {
var $, Trello, apiEndpoint, authEndpoint, authorizeURL, baseURL, collection, fn, fn1, i, intentEndpoint, j, key, len, len1, localStorage, location, parseRestArgs, readStorage, ref, ref1, storagePrefix, token, type, version, writeStorage;
$ = jQuery;
key = opts.key, token = opts.token, apiEndpoint = opts.apiEndpoint, authEndpoint = opts.authEndpoint, intentEndpoint = opts.intentEndpoint, version = opts.version;
baseURL = apiEndpoint + "/" + version + "/";
location = window.location;
Trello = {
version: function() {
return version;
},
key: function() {
return key;
},
setKey: function(newKey) {
key = newKey;
},
token: function() {
return token;
},
setToken: function(newToken) {
token = newToken;
},
rest: function() {
var args, error, method, params, path, ref, success;
method = arguments[0], args = 2 <= arguments.length ? slice.call(arguments, 1) : [];
ref = parseRestArgs(args), path = ref[0], params = ref[1], success = ref[2], error = ref[3];
opts = {
url: "" + baseURL + path,
type: method,
data: {},
dataType: "json",
success: success,
error: error
};
if (!$.support.cors) {
opts.dataType = "jsonp";
if (method !== "GET") {
opts.type = "GET";
$.extend(opts.data, {
_method: method
});
}
}
if (key) {
opts.data.key = key;
}
if (token) {
opts.data.token = token;
}
if (params != null) {
$.extend(opts.data, params);
}
if (method === 'UPLOAD' && typeof (params) === "string" && params.length > 5) {
var xhr = new XMLHttpRequest();
xhr.open('get', params);
xhr.responseType = 'blob'; // Use blob to get the mimetype
xhr.onload = function() {
var fileReader = new FileReader();
fileReader.onload = function() {
var filename = (params.split('/').pop().split('#')[0].split('?')[0]) || params || '?'; // Removes # or ? after filename
var file = new File([this.result], filename);
var form = new FormData();
form.append("file", file);
$.each(['key', 'token'], function(iter, item) {
form.append(item, opts.data[item] || 'ERROR! Missing "' + item + '"');
});
$.extend(opts, {
method: "POST",
data: form,
cache: false,
contentType: false,
processData: false
});
return $.ajax(opts);
};
fileReader.readAsArrayBuffer(xhr.response); // Use filereader on blob to get content
};
xhr.send();
} else {
return $.ajax(opts);
}
},
authorized: function() {
return token != null;
},
deauthorize: function() {
token = null;
writeStorage("token", token);
},
authorize: function(userOpts) {
var k, persistToken, ref, regexToken, scope, v;
opts = $.extend(true, {
type: "redirect",
persist: true,
interactive: true,
scope: {
read: true,
write: false,
account: false
},
expiration: "30days"
}, userOpts);
regexToken = /[&#]?token=([0-9a-f]{64})/;
persistToken = function() {
if (opts.persist && (token != null)) {
return writeStorage("token", token);
}
};
if (opts.persist) {
if (token == null) {
token = readStorage("token");
}
}
if (token == null) {
token = (ref = regexToken.exec(location.hash)) != null ? ref[1] : void 0;
}
if (this.authorized()) {
persistToken();
location.hash = location.hash.replace(regexToken, "");
return typeof opts.success === "function" ? opts.success() : void 0;
}
if (!opts.interactive) {
return typeof opts.error === "function" ? opts.error() : void 0;
}
scope = ((function() {
var ref1, results;
ref1 = opts.scope;
results = [];
for (k in ref1) {
v = ref1[k];
if (v) {
results.push(k);
}
}
return results;
})()).join(",");
switch (opts.type) {
case "popup":
(function() {
var authWindow, height, left, origin, receiveMessage, ref1, top, width;
waitUntil("authorized", (function(_this) {
return function(isAuthorized) {
if (isAuthorized) {
persistToken();
return typeof opts.success === "function" ? opts.success() : void 0;
} else {
return typeof opts.error === "function" ? opts.error() : void 0;
}
};
})(this));
width = 420;
height = 470;
left = window.screenX + (window.innerWidth - width) / 2;
top = window.screenY + (window.innerHeight - height) / 2;
origin = (ref1 = /^[a-z]+:\/\/[^\/]*/.exec(location)) != null ? ref1[0] : void 0;
authWindow = window.open(authorizeURL({
return_url: origin,
callback_method: "postMessage",
scope: scope,
expiration: opts.expiration,
name: opts.name
}), "trello", "width=" + width + ",height=" + height + ",left=" + left + ",top=" + top);
receiveMessage = function(event) {
var ref2;
if (event.origin !== authEndpoint || event.source !== authWindow) {
return;
}
if ((ref2 = event.source) != null) {
ref2.close();
}
if ((event.data != null) && /[0-9a-f]{64}/.test(event.data)) {
token = event.data;
} else {
token = null;
}
if (typeof window.removeEventListener === "function") {
window.removeEventListener("message", receiveMessage, false);
}
isReady("authorized", Trello.authorized());
};
return typeof window.addEventListener === "function" ? window.addEventListener("message", receiveMessage, false) : void 0;
})();
break;
default:
window.location = authorizeURL({
redirect_uri: location.href,
callback_method: "fragment",
scope: scope,
expiration: opts.expiration,
name: opts.name
});
}
},
addCard: function(options, next) {
var baseArgs, getCard;
baseArgs = {
mode: 'popup',
source: key || window.location.host
};
getCard = function(callback) {
var height, left, returnUrl, top, width;
returnUrl = function(e) {
var data;
window.removeEventListener('message', returnUrl);
try {
data = JSON.parse(e.data);
if (data.success) {
return callback(null, data.card);
} else {
return callback(new Error(data.error));
}
} catch (error1) {}
};
if (typeof window.addEventListener === "function") {
window.addEventListener('message', returnUrl, false);
}
width = 500;
height = 600;
left = window.screenX + (window.outerWidth - width) / 2;
top = window.screenY + (window.outerHeight - height) / 2;
return window.open(intentEndpoint + "/add-card?" + $.param($.extend(baseArgs, options)), "trello", "width=" + width + ",height=" + height + ",left=" + left + ",top=" + top);
};
if (next != null) {
return getCard(next);
} else if (window.Promise) {
return new Promise(function(resolve, reject) {
return getCard(function(err, card) {
if (err) {
return reject(err);
} else {
return resolve(card);
}
});
});
} else {
return getCard(function() {});
}
}
};
ref = ["GET", "PUT", "POST", "DELETE", "UPLOAD"];
fn = function(type) {
return Trello[type.toLowerCase()] = function() {
return this.rest.apply(this, [type].concat(slice.call(arguments)));
};
};
for (i = 0, len = ref.length; i < len; i++) {
type = ref[i];
fn(type);
}
Trello.del = Trello["delete"];
ref1 = ["actions", "cards", "checklists", "boards", "lists", "members", "organizations", "lists"];
fn1 = function(collection) {
return Trello[collection] = {
get: function(id, params, success, error) {
return Trello.get(collection + "/" + id, params, success, error);
}
};
};
for (j = 0, len1 = ref1.length; j < len1; j++) {
collection = ref1[j];
fn1(collection);
}
window.Trello = Trello;
authorizeURL = function(args) {
var baseArgs;
baseArgs = {
response_type: "token",
key: key
};
return authEndpoint + "/" + version + "/authorize?" + $.param($.extend(baseArgs, args));
};
parseRestArgs = function(arg) {
var error, params, path, success;
path = arg[0], params = arg[1], success = arg[2], error = arg[3];
if (isFunction(params)) {
error = success;
success = params;
params = {};
}
path = path.replace(/^\/*/, "");
return [path, params, success, error];
};
localStorage = window.localStorage;
if (localStorage != null) {
storagePrefix = "trello_";
readStorage = function(key) {
return localStorage[storagePrefix + key];
};
writeStorage = function(key, value) {
if (value === null) {
return delete localStorage[storagePrefix + key];
} else {
return localStorage[storagePrefix + key] = value;
}
};
} else {
readStorage = writeStorage = function() {};
}
};
deferred = {};
ready = {};
waitUntil = function(name, fx) {
if (ready[name] != null) {
return fx(ready[name]);
} else {
return (deferred[name] != null ? deferred[name] : deferred[name] = []).push(fx);
}
};
isReady = function(name, value) {
var fx, fxs, i, len;
ready[name] = value;
if (deferred[name]) {
fxs = deferred[name];
delete deferred[name];
for (i = 0, len = fxs.length; i < len; i++) {
fx = fxs[i];
fx(value);
}
}
};
isFunction = function(val) {
return typeof val === "function";
};
wrapper(window, jQuery, opts);
}).call(this);
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.2.3/jquery.min.js"></script>