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Diffstat (limited to 'thirdparty/systemjs/lib/scriptLoader.js')
-rw-r--r-- | thirdparty/systemjs/lib/scriptLoader.js | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/thirdparty/systemjs/lib/scriptLoader.js b/thirdparty/systemjs/lib/scriptLoader.js new file mode 100644 index 000000000..8bd1d4b3e --- /dev/null +++ b/thirdparty/systemjs/lib/scriptLoader.js @@ -0,0 +1,196 @@ +/* + * Script tag fetch + * + * When load.metadata.scriptLoad is true, we load via script tag injection. + */ +(function() { + + if (typeof document != 'undefined') + var head = document.getElementsByTagName('head')[0]; + + var curSystem; + var curRequire; + + // if doing worker executing, this is set to the load record being executed + var workerLoad = null; + + // interactive mode handling method courtesy RequireJS + var ieEvents = head && (function() { + var s = document.createElement('script'); + var isOpera = typeof opera !== 'undefined' && opera.toString() === '[object Opera]'; + return s.attachEvent && !(s.attachEvent.toString && s.attachEvent.toString().indexOf('[native code') < 0) && !isOpera; + })(); + + // IE interactive-only part + // we store loading scripts array as { script: <script>, load: {...} } + var interactiveLoadingScripts = []; + var interactiveScript; + function getInteractiveScriptLoad() { + if (interactiveScript && interactiveScript.script.readyState === 'interactive') + return interactiveScript.load; + + for (var i = 0; i < interactiveLoadingScripts.length; i++) + if (interactiveLoadingScripts[i].script.readyState == 'interactive') { + interactiveScript = interactiveLoadingScripts[i]; + return interactiveScript.load; + } + } + + // System.register, System.registerDynamic, AMD define pipeline + // this is called by the above methods when they execute + // we then run the reduceRegister_ collection function either immediately + // if we are in IE and know the currently executing script (interactive) + // or later if we need to wait for the synchronous load callback to know the script + var loadingCnt = 0; + var registerQueue = []; + hook('pushRegister_', function(pushRegister) { + return function(register) { + // if using eval-execution then skip + if (pushRegister.call(this, register)) + return false; + + // if using worker execution, then we're done + if (workerLoad) + this.reduceRegister_(workerLoad, register); + + // detect if we know the currently executing load (IE) + // if so, immediately call reduceRegister + else if (ieEvents) + this.reduceRegister_(getInteractiveScriptLoad(), register); + + // otherwise, add to our execution queue + // to call reduceRegister on sync script load event + else if (loadingCnt) + registerQueue.push(register); + + // if we're not currently loading anything though + // then do the reduction against a null load + // (out of band named define or named register) + // note even in non-script environments, this catch is used + else + this.reduceRegister_(null, register); + + return true; + }; + }); + + function webWorkerImport(loader, load) { + return new Promise(function(resolve, reject) { + if (load.metadata.integrity) + reject(new Error('Subresource integrity checking is not supported in web workers.')); + + workerLoad = load; + try { + importScripts(load.address); + } + catch(e) { + workerLoad = null; + reject(e); + } + workerLoad = null; + + // if nothing registered, then something went wrong + if (!load.metadata.entry) + reject(new Error(load.address + ' did not call System.register or AMD define. If loading a global, ensure the meta format is set to global.')); + + resolve(''); + }); + } + + // override fetch to use script injection + hook('fetch', function(fetch) { + return function(load) { + var loader = this; + + if (load.metadata.format == 'json' || !load.metadata.scriptLoad || (!isBrowser && !isWorker)) + return fetch.call(this, load); + + if (isWorker) + return webWorkerImport(loader, load); + + return new Promise(function(resolve, reject) { + var s = document.createElement('script'); + + s.async = true; + + if (load.metadata.crossOrigin) + s.crossOrigin = load.metadata.crossOrigin; + + if (load.metadata.integrity) + s.setAttribute('integrity', load.metadata.integrity); + + if (ieEvents) { + s.attachEvent('onreadystatechange', complete); + interactiveLoadingScripts.push({ + script: s, + load: load + }); + } + else { + s.addEventListener('load', complete, false); + s.addEventListener('error', error, false); + } + + loadingCnt++; + + curSystem = __global.System; + curRequire = __global.require; + + s.src = load.address; + head.appendChild(s); + + function complete(evt) { + if (s.readyState && s.readyState != 'loaded' && s.readyState != 'complete') + return; + + loadingCnt--; + + // complete call is sync on execution finish + // (in ie already done reductions) + if (!load.metadata.entry && !registerQueue.length) { + loader.reduceRegister_(load); + } + else if (!ieEvents) { + for (var i = 0; i < registerQueue.length; i++) + loader.reduceRegister_(load, registerQueue[i]); + registerQueue = []; + } + + cleanup(); + + // if nothing registered, then something went wrong + if (!load.metadata.entry && !load.metadata.bundle) + reject(new Error(load.name + ' did not call System.register or AMD define. If loading a global module configure the global name via the meta exports property for script injection support.')); + + resolve(''); + } + + function error(evt) { + cleanup(); + reject(new Error('Unable to load script ' + load.address)); + } + + function cleanup() { + __global.System = curSystem; + __global.require = curRequire; + + if (s.detachEvent) { + s.detachEvent('onreadystatechange', complete); + for (var i = 0; i < interactiveLoadingScripts.length; i++) + if (interactiveLoadingScripts[i].script == s) { + if (interactiveScript && interactiveScript.script == s) + interactiveScript = null; + interactiveLoadingScripts.splice(i, 1); + } + } + else { + s.removeEventListener('load', complete, false); + s.removeEventListener('error', error, false); + } + + head.removeChild(s); + } + }); + }; + }); +})(); |