prismic.io
Version:
JavaScript development kit for prismic.io
242 lines (204 loc) • 7.15 kB
JavaScript
;
var createError = function(status, message) {
var err = new Error(message);
err.status = status;
return err;
};
// -- Request handlers
var ajaxRequest = (function() {
if(typeof XMLHttpRequest != 'undefined' && 'withCredentials' in new XMLHttpRequest()) {
return function(url, callback) {
var xhr = new XMLHttpRequest();
// Called on success
var resolve = function() {
var ttl, cacheControl = /max-age\s*=\s*(\d+)/.exec(
xhr.getResponseHeader('Cache-Control'));
if (cacheControl && cacheControl.length > 1) {
ttl = parseInt(cacheControl[1], 10);
}
callback(null, JSON.parse(xhr.responseText), xhr, ttl);
};
// Called on error
var reject = function() {
var status = xhr.status;
callback(createError(status, "Unexpected status code [" + status + "] on URL "+url), null, xhr);
};
// Bind the XHR finished callback
xhr.onreadystatechange = function() {
if (xhr.readyState === 4) {
if(xhr.status && xhr.status == 200) {
resolve();
} else {
reject();
}
}
};
// Open the XHR
xhr.open('GET', url, true);
// Kit version (can't override the user-agent client side)
// xhr.setRequestHeader("X-Prismic-User-Agent", "Prismic-javascript-kit/%VERSION%".replace("%VERSION%", Global.Prismic.version));
// Json request
xhr.setRequestHeader('Accept', 'application/json');
// Send the XHR
xhr.send();
};
}
return null;
});
var xdomainRequest = (function() {
if(typeof XDomainRequest != 'undefined') { // Internet Explorer
return function(url, callback) {
var xdr = new XDomainRequest();
// Called on success
var resolve = function() {
callback(null, JSON.parse(xdr.responseText), xdr, 0);
};
// Called on error
var reject = function(msg) {
callback(new Error(msg), null, xdr);
};
// Bind the XDR finished callback
xdr.onload = function() {
resolve(xdr);
};
// Bind the XDR error callback
xdr.onerror = function() {
reject("Unexpected status code on URL " + url);
};
// Open the XHR
xdr.open('GET', url, true);
// Bind the XDR timeout callback
xdr.ontimeout = function () {
reject("Request timeout");
};
// Empty callback. IE sometimes abort the reqeust if
// this is not present
xdr.onprogress = function () { };
xdr.send();
};
}
return null;
});
// The experimental fetch API, required by React Native for example.
// We still use browser requests by default because there could be an
// incomplete polyfill in the context (lacking CORS for example)
var fetchRequest = (function() {
if (typeof fetch == "function") {
var pjson = require('../package.json');
return function(requestUrl, callback) {
fetch(requestUrl, {
headers: {
'Accept': 'application/json',
'User-Agent': 'Prismic-javascript-kit/' + pjson.version + " NodeJS/" + process.version
}
}).then(function (response) {
if (~~(response.status / 100 != 2)) {
throw new createError(response.status, "Unexpected status code [" + response.status + "] on URL " + requestUrl);
} else {
return response.json().then(function(json) {
return {
response: response,
json: json
};
});
}
}).then(function(next) {
var response = next.response;
var json = next.json;
var cacheControl = response.headers['cache-control'];
var ttl = cacheControl && /max-age=(\d+)/.test(cacheControl) ? parseInt(/max-age=(\d+)/.exec(cacheControl)[1], 10) : undefined;
callback(null, json, response, ttl);
}).catch(function (error) {
callback(error);
});
};
}
return null;
});
var nodeJSRequest = (function() {
if(typeof require == 'function' && require('http')) {
var http = require('http'),
https = require('https'),
url = require('url'),
pjson = require('../package.json');
return function(requestUrl, callback) {
var parsed = url.parse(requestUrl),
h = parsed.protocol == 'https:' ? https : http,
options = {
hostname: parsed.hostname,
path: parsed.path,
query: parsed.query,
headers: {
'Accept': 'application/json',
'User-Agent': 'Prismic-javascript-kit/' + pjson.version + " NodeJS/" + process.version
}
};
if (!requestUrl) {
var e = new Error('dummy');
var stack = e.stack.replace(/^[^\(]+?[\n$]/gm, '')
.replace(/^\s+at\s+/gm, '')
.replace(/^Object.<anonymous>\s*\(/gm, '{anonymous}()@')
.split('\n');
console.log(stack);
}
var request = h.get(options, function(response) {
if (response.statusCode && response.statusCode == 200) {
var jsonStr = '';
response.setEncoding('utf8');
response.on('data', function (chunk) {
jsonStr += chunk;
});
response.on('end', function () {
var json;
try {
json = JSON.parse(jsonStr);
} catch (ex) {
console.log("Failed to parse json: " + jsonStr, ex);
}
var cacheControl = response.headers['cache-control'];
var ttl = cacheControl && /max-age=(\d+)/.test(cacheControl) ? parseInt(/max-age=(\d+)/.exec(cacheControl)[1], 10) : undefined;
callback(null, json, response, ttl);
});
} else {
callback(createError(response.statusCode, "Unexpected status code [" + response.statusCode + "] on URL "+requestUrl), null, response);
}
});
// properly handle timeouts
request.on('error', function(err) {
callback(new Error("Unexpected error on URL "+requestUrl), null, err);
});
};
}
return null;
});
// Number of maximum simultaneous connections to the prismic server
var MAX_CONNECTIONS = 20;
// Number of requests currently running (capped by MAX_CONNECTIONS)
var running = 0;
// Requests in queue
var queue = [];
var processQueue = function() {
if (queue.length === 0 || running >= MAX_CONNECTIONS) {
return;
}
running++;
var next = queue.shift();
var fn = ajaxRequest() || xdomainRequest() || fetchRequest() || nodeJSRequest() ||
(function() { throw new Error("No request handler available (tried XMLHttpRequest, fetch & NodeJS)"); })();
fn.call(this, next.url, function(error, result, xhr, ttl) {
running--;
next.callback(error, result, xhr, ttl);
processQueue();
});
};
var request = function (url, callback) {
queue.push({
'url': url,
'callback': callback
});
processQueue();
};
module.exports = {
MAX_CONNECTIONS: MAX_CONNECTIONS, // Number of maximum simultaneous connections to the prismic server
request: request
};