@darwino/darwino/src/Fetch.js

A set of Javascript classes and utilities

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 *
 * Darwino Inc Confidential.
 *
 * (c) Copyright Darwino Inc. 2014-2016.
 *
 * Notice: The information contained in the source code for these files is the property 
 * of Darwino Inc. which, with its licensors, if any, owns all the intellectual property 
 * rights, including all copyright rights thereto.  Such information may only be used 
 * for debugging, troubleshooting and informational purposes.  All other uses of this information, 
 * including any production or commercial uses, are prohibited. 
 */

import Utils from "./Utils"
import DEV_OPTIONS from "./dev";

/**
 * JavaScript fetch utilities
 * 
 * The exported functions extend the JavaScript 'fetch' function by capturing HTTP error and
 * throw an exception to the promise (standard 'fetch' only does that for HTTP errors). It also
 * detects if the application is running in development mode ('webpack dev server') and then
 * preprend the data server URL while ensuring that the cross domain credentials are also 
 * passed by the request.
 *
 */
 
function isError(response) {
	return !response.ok
}

export function fetchEx(input,init,config) {
	input = makeUrl(input);
	// if(DEV_OPTIONS.WEBPACK) {
	// 	if(Utils.isString(input) && DEV_OPTIONS.serverPrefix) {
	// 		if(input.indexOf("://")<0) {
	// 			input = Utils.concatPath(DEV_OPTIONS.serverPrefix,input);
	// 		}
	// 	}
	// }
	init = {...init, credentials: DEV_OPTIONS.credentials} // "same-origin" for cookies
	return fetch(input,init)
		.then(response => {
			if(((config && config.isError)||isError)(response)) {
				return response.text().then(content => { 
					console.log("Fetch error "+response.status + ": " + response.statusText+"\n"+content);
					let jsonContent = null;
					let message = response.status + ": " + response.statusText
					try {
						jsonContent = JSON.parse(content);
						if(jsonContent.message) {
							message += "\n"+jsonContent.message
						}
					} catch(e) {} // Ok, not JSON
					throw {message,statusText:response.statusText,status:response.status,content,jsonContent}; 
				});
			}
			return response;
		})
}

export function fetchJson(input,init,config) {
	return fetchEx(input,init,config).then((response) => {
		try {
			return response.json();
		} catch(e) {
            throw {message:e.toString(),exception:e}
        }
	});
}

export function fetchText(input,init,config) {
	return fetchEx(input,init,config).then((response) => {
		return response.text();
	});
}

export function makeUrl(url,parts,params) {
	if(!url) url = ""
	if(DEV_OPTIONS.WEBPACK) {
		if(url.indexOf("://")<0 && DEV_OPTIONS.serverPrefix) {
			url = Utils.concatPath(DEV_OPTIONS.serverPrefix,url);
		}
	}
	if(parts && parts.length) {
		for(let i=0; i<parts.length; i++) {
			let part = parts[i].toString();
			if(part) {
				url = Utils.concatPath(url,encodeURIComponent(part));
			}
		}
	}
	if(params) {
		return addQueryString(url,makeQueryString(params))
	}
	return url;
}

export function makeWsUrl(url) {
	if(!url) url = ""
	if(url.indexOf("://")<0) {
		if(DEV_OPTIONS.WEBPACK) {
			if(DEV_OPTIONS.wsPrefix) {
				url = Utils.concatPath(DEV_OPTIONS.wsPrefix,url);
			}
		} else {
			// Make an absolute URL using a <a>
			const a = document.createElement('a');
			a.href = url;
			url = "ws" + a.href.substring(4); // Replace http by ws (works also with https -> wss)
		}
	}
	return url;
}

export function makeQueryString(params) {
	if(params) {
		let qs = "";
		for(let pa in params) {
			let v = params[pa].toString();
			if(qs) qs += '&'
			qs += encodeURIComponent(pa) + (v ? ('=' + encodeURIComponent(v)) : "");
		}
		return qs;
	}
	return "";
}

export function addQueryString(url,qs) {
	if(qs) {
		const ch = url.indexOf('?')>=0 ? '&' : '?'
		url += ch + qs
	}
	return url
}