jQuery.sap.require用于解析一个或多个模块依赖。
jQuery.sap.require函数源码在jquery.sap.global.js，执行时可在sap-ui-core.js中找到。
通过下面的源代码可知，jQuery.sap.require首先通过ui5ToRJS将javascript类名转换为js文件名，例如sap.m.Dialog转换为sap/m/Dialog.js，然后执行requireModule函数。
requireModule函数查找该模块在sap.ui.core.Core对象的mModules中是否存在，不存在则添加并设为INITIAL状态，判断模块是否已经被加载、执行过，如果没有则设为LOADING状态并通过ajax以同步方式加载代码（如果当前是debug模式则选择-dbg版本的js文件URL），加载失败设为FAILED状态，加载成功则设为LOADED状态并执行代码，执行失败设为FAILED状态，执行成功设为READY状态。
jQuery.sap.require = function(vModuleName, fnCallback) {
if ( arguments.length > 1 ) {
// legacy mode with multiple arguments, each representing a dependency
for (var i = 0; i < arguments.length; i++) {
jQuery.sap.require(arguments[i]);
}
return this;
}
// check for an object as parameter for sModuleName
// in case of this the object contains the module name and the type
// which could be {modName: "sap.ui.core.Dev", type: "view"}
if (typeof (vModuleName) === "object") {
jQuery.sap.assert(!vModuleName.type ||
jQuery.inArray(vModuleName.type, mKnownSubtypes.js) >= 0,
"type must be empty or one of " + mKnownSubtypes.js.join(", "));
vModuleName = ui5ToRJS(vModuleName.modName) +
(vModuleName.type ? "." + vModuleName.type : "") + ".js";
} else {
vModuleName = ui5ToRJS(vModuleName) + ".js";
}
requireModule(vModuleName);
return this; // TODO
};
function ui5ToRJS(sName) {
if ( /^sap\.ui\.thirdparty\.jquery\.jquery-/.test(sName) ) {
return "sap/ui/thirdparty/jquery/jquery-" +
sName.slice("sap.ui.thirdparty.jquery.jquery-".length);
} else if ( /^jquery\.sap\./.test(sName) ) {
return sName;
}
return sName.replace(/\./g, "/");
}
function requireModule(sModuleName) {
var m = rJSSubtypes.exec(sModuleName),
sBaseName, sType, oModule, aExtensions, i;
// only for robustness, should not be possible
// by design (all callers append '.js')
if ( !m ) {
log.error("can only require Javascript module, not " + sModuleName);
return;
}
// in case of having a type specified ignore the type for the module path
// creation and add it as file extension
sBaseName = sModuleName.slice(0, m.index);
sType = m[0]; // must be a normalized resource
// name of type .js sType can be empty
// or one of view|controller|fragment
oModule = mModules[sModuleName] ||
(mModules[sModuleName] = { state : INITIAL });
if ( log.isLoggable() ) {
log.debug(sLogPrefix + "require '" + sModuleName +
"' of type '" + sType + "'");
}
// check if module has been loaded already
if ( oModule.state !== INITIAL ) {
if ( oModule.state === PRELOADED ) {
oModule.state = LOADED;
execModule(sModuleName);
}
if ( oModule.state === READY ) {
if ( log.isLoggable() ) {
log.debug(sLogPrefix + "module '" + sModuleName +
"' has already been loaded (skipped).");
}
return this;
} else if ( oModule.state === FAILED ) {
throw new Error("found in negative cache: '" + sModuleName +
"' from " + oModule.url + ": " + oModule.error);
} else {
// currently loading
return this;
}
}
// set marker for loading modules (to break cycles)
oModule.state = LOADING;
// if debug is enabled, try to load debug module first
aExtensions = window["sap-ui-loaddbg"] ? ["-dbg", ""] : [""];
for (i = 0; i < aExtensions.length && oModule.state !== LOADED; i++) {
// create module URL for the current extension
oModule.url = getResourcePath(sBaseName, aExtensions[i] + sType);
if ( log.isLoggable() ) {
log.debug(sLogPrefix + "loading " + (aExtensions[i] ? aExtensions[i] +
" version of " : "") + "'" + sModuleName +
"' from '" + oModule.url + "'");
}
jQuery.ajax({
url : oModule.url,
dataType : 'text',
async : false,
success : function(response, textStatus, xhr) {
oModule.state = LOADED;
oModule.data = response;
},
error : function(xhr, textStatus, error) {
oModule.state = FAILED;
oModule.error = xhr ? xhr.status + " - " + xhr.statusText : textStatus;
}
});
}
// execute module __after__ loading it, this reduces the required stack space!
if ( oModule.state === LOADED ) {
execModule(sModuleName);
}
if ( oModule.state !== READY ) {
throw new Error("failed to load '" + sModuleName +
"' from " + oModule.url + ": " + oModule.error);
}
}
// sModuleName must be a normalized resource name of type .js
function execModule(sModuleName) {
var oModule = mModules[sModuleName],
sOldPrefix, sScript, vAMD;
if ( oModule && oModule.state === LOADED &&
typeof oModule.data !== "undefined" ) {
// check whether the module is known to use an existing AMD loader,
// remember the AMD flag
vAMD = mAMDShim[sModuleName] && typeof window.define === "function" &&
window.define.amd;
try {
if ( vAMD ) {
// temp. remove the AMD Flag from the loader
delete window.define.amd;
}
if ( log.isLoggable() ) {
log.debug(sLogPrefix + "executing '" + sModuleName + "'");
sOldPrefix = sLogPrefix;
sLogPrefix = sLogPrefix + ": ";
}
// execute the script in the window context
oModule.state = EXECUTING;
_execStack.push(sModuleName);
if ( typeof oModule.data === "function" ) {
oModule.data.call(window);
} else {
sScript = oModule.data;
// sourceURL: Firebug, Chrome, Safari and IE11 debugging help,
// appending the string seems to cost ZERO performance
// Note: IE11 supports sourceURL even when running in IE9 or IE10 mode
// Note: make URL absolute so Chrome displays the file tree correctly
// Note: do not append if there is already a sourceURL / sourceMappingURL
if (sScript && !sScript.match(/\/\/[#@] source(Mapping)?URL=.*$/)) {
sScript += "\n//# sourceURL=" +
URI(oModule.url).absoluteTo(sDocumentLocation);
}
// framework internal hook to intercept the loaded script and modify
// it before executing the script - e.g. useful for client side coverage
if (typeof jQuery.sap.require._hook === "function") {
sScript = jQuery.sap.require._hook(sScript, sModuleName);
}
if (_window.execScript && (!oModule.data ||
oModule.data.length < MAX_EXEC_SCRIPT_LENGTH) ) {
try {
oModule.data && _window.execScript(sScript);
// execScript fails if data is empty
} catch (e) {
_execStack.pop();
// eval again with different approach -
// should fail with a more informative exception
jQuery.sap.globaleval_r(oModule.data);
throw e; // rethrow err in case globalEval succeeded unexpectedly
}
} else {
_window.eval_r(sScript);
}
}
_execStack.pop();
oModule.state = READY;
oModule.data = undefined;
// best guess for legacy modules that don't use sap.ui.define
// TODO implement fallback for raw modules
oModule.content = oModule.content ||
jQuery.sap.getObject(urnToUI5(sModuleName));
if ( log.isLoggable() ) {
sLogPrefix = sOldPrefix;
log.debug(sLogPrefix + "finished executing '" + sModuleName + "'");
}
} catch (err) {
oModule.state = FAILED;
oModule.error = ((err.toString && err.toString()) || err.message) +
(err.line ? "(line " + err.line + ")" : "" );
oModule.data = undefined;
if ( window["sap-ui-debug"] &&
(/sap-ui-xx-show(L|-l)oad(E|-e)rrors=(true|x|X)/.test(location.search)
|| oCfgData["xx-showloaderrors"]) ) {
log.error("error while evaluating " + sModuleName +
", embedding again via script tag to enforce a stack trace (see below)");
jQuery.sap.includeScript(oModule.url);
return;
}
} finally {
// restore AMD flag
if ( vAMD ) {
window.define.amd = vAMD;
}
}
}
}