fipamo/brain/tools/utilities/DataUtils.js

139 lines
5 KiB
JavaScript

export const REQUEST_TYPE_POST = "POST";
export const REQUEST_TYPE_GET = "GET";
export const REQUEST_TYPE_PUT = "PUT";
export const REQUEST_TYPE_DELETE = "DELETE";
export const CONTENT_TYPE_JSON = 'json';
export const CONTENT_TYPE_FORM = 'x-www-form-urlencoded';
import EventEmitter from '../events/EventEmitter';
import * as DataEvent from '../events/DataEvent';
class DataUtils extends EventEmitter
{
//--------------------------
// constructor
//--------------------------
constructor()
{
super();
var self = this;
}
//--------------------------
// methods
//--------------------------
request(requestURL, eventType, requestType = REQUEST_TYPE_GET, contentType = CONTENT_TYPE_JSON, requestData = null)
{
var self = this;
return new Promise(function(resolve, reject)
{
var request = new XMLHttpRequest();
request.upload.onprogress = self.handleLoadProgress;
request.open(requestType, requestURL, true);
request.onload = function(e)
{
if (request.status == 200)
{
resolve(
{
request,
eventType
});
}
else
{
reject(
{
request,
eventType
});
};
};
if (requestType == REQUEST_TYPE_PUT || requestType == REQUEST_TYPE_POST)
{
switch (contentType)
{
case CONTENT_TYPE_JSON:
request.setRequestHeader("Content-type", "application/" + contentType);
request.send(JSON.stringify(requestData));
break;
case CONTENT_TYPE_FORM:
request.send(requestData);
break;
}
}
else
{
request.send();
}
})
}
imgLoad(url)
{
'use strict';
// Create new promise with the Promise() constructor;
// This has as its argument a function with two parameters, resolve and reject
return new Promise(function(resolve, reject)
{
// Standard XHR to load an image
var request = new XMLHttpRequest();
request.open('GET', url);
request.responseType = 'blob';
// When the request loads, check whether it was successful
request.onload = function()
{
if (request.status === 200)
{
// If successful, resolve the promise by passing back the request response
resolve(request.response);
}
else
{
// If it fails, reject the promise with a error message
reject(new Error('Image didn\'t load successfully; error code:' + request.statusText));
}
};
request.onerror = function()
{
// Also deal with the case when the entire request fails to begin with
// This is probably a network error, so reject the promise with an appropriate message
reject(new Error('There was a network error.'));
};
// Send the request
request.send();
});
}
loadImage(src)
{
'use strict';
let self = this;
return new Promise(function(resolve, reject)
{
// Get a reference to the body element, and create a new image object
var body = document.querySelector('body'),
myImage = new Image();
myImage.crossOrigin = ""; // or "anonymous"
// Call the function with the URL we want to load, but then chain the
// promise then() method on to the end of it. This contains two callbacks
self.imgLoad(src).then(function(response)
{
// The first runs when the promise resolves, with the request.reponse specified within the resolve() method.
var imageURL = window.URL.createObjectURL(response);
resolve(imageURL);
//$('background-content').setStyle('background-image', 'url('+imageURL+')') //myImage.src = imageURL;
//console.log(imageURL);
//body.appendChild(myImage);
// The second runs when the promise is rejected, and logs the Error specified with the reject() method.
}, function(Error)
{
reject(Error)
});
});
}
//--------------------------
// event handlers
//--------------------------
handleLoadProgress(e)
{
var percentComplete = Math.ceil((e.loaded / e.total) * 100);
//console.log(percentComplete);
}
}
export default DataUtils;