GAS：如何在处理函数中使用变量时更改全局变量值并保留其更改的值？ [英] GAS: How to change a global variable value and preserve its changed value when using the variable in a handler function?
问题描述
我的脚本里有这个全局变量：
var targetDocId ='尚未通知文档ID';
我试图在主函数内改变这个全局变量的值：
function generatePersonDatasheet（）{
var target = createDuplicateDocument（template，docName）;
var link = target.getUrl（）;
targetDocId = target.getId（）; //< -------- HERE
if（theses == 1）{
Logger.log（going to showList（））;
return showList（）;
}
showURL（docName，link）;
}
之后，我尝试访问更改后的全局变量值处理函数：
$ p $ function submit（e）{
var numberOfItems = Number（e.parameter.checkbox_total）;
var thesesArrays = [];
for（var i = 0; i< numberOfItems; i ++）{
if（e.parameter ['checkbox_isChecked _'+ i] =='true'）{
thesesArrays.push（ fact_list [I]）;
for（var i = 0; i< thesesArrays.length; i ++）{
var thesesId = thesesArrays [i] [2];
var thesesType = thesesArrays [i] [1];
importTheses（targetDocId，thesesId，thesesType）; //< ----- HERE
}
return UiApp.getActiveApplication（）。close（）;
}
函数importTheses（targetDocId，thesesId，thesesType）{
var targetDoc = DocumentApp.openById（targetDocId）;
var targetDocParagraphs = targetDoc.getParagraphs（）;
var targetDocElements = targetDocParagraphs.getNumChildren（）;
var thesesDoc = DocumentApp.openById（thesesId）;
var thesesParagraphs = thesesDoc.getParagraphs（）;
var thesesElements = thesesDoc.getNumChildren（）;
var eltargetDoc = [];
var elTheses = []; （var j = 0; j< targetDocElements; ++ j）{
var targetDocElement = targetDoc.getChild（j）;
。
eltargetDoc [j] = targetDocElement.getText（）;
if（el [j] == thesesType）{
for（var k = 0; k< thesesParagraphs-1; ++ k）{
var thesesElement = thesesDoc.getChild（k ）;
elTheses [k] = thesesDoc.getText（）;
targetDoc.insertParagraph（j，elTheses [k]）;
}
}
}
}
但，只要我尝试改变 targetDocId ，当它用作 importTheses（targetDocId，thesesId，thesesType）的参数时; 它仍然具有'没有通知文档ID'的值，即使我已经改变了它，就像程序从头开始运行一样。是否可以选择重置为原始值行为？或者我必须使用scriptDB或ScriptProperties来存储全局变量的值？
脚本的每个单独执行是在新的执行实例中完成。因此，在代码块之外定义的任何变量（也称为全局变量）因此对于该实例是唯一的。当事件调用触发器函数时，它会在自己的实例中运行，并且它设置的任何全局值仅对该实例可见;例如，由电子表格或文档UI调用的另一个函数将拥有其自己版本的非范围对象（全局）。
定义和检索 targetDocId 将是缓存服务。 note
function get_targetDocId（）{
var cache = CacheService.getPublicCache（）;
var cached = cache.get（targetDocId）;
if（cached！= null）{
return cached;
}
var target = createDuplicateDocument（template，docName）; ///需要为已存在的文档添加处理
var link = target.getUrl（）;
var contents = target.getId（）;
cache.put（targetDocId，contents，1500）; //缓存25分钟
返回内容;
$ / code> 现在不用试图使用全局变量，只需调用这个函数： / p>
...
var targetDoc = DocumentApp.openById（get_targetDocId（））; b
note 缓存服务是可用于Google Apps脚本的持久性存储的一个示例。在撰写答案之后，引入了属性服务，在执行实例之间持久化全局变量。
观察：看起来您正在使用全局（静态）for tempate 和 docName ，因为 generatePersonDatasheet（）。您可以简单地生成targetDocId。
Bug：在写入时， get_targetDocId（）会创建每次需要刷新缓存时（15分钟），都会有一个新的 docName 副本。您应该添加处理以预先存在的文件的可能性。 （您的现有 onOpen（）也是如此。）
I have this global variable in my script:
var targetDocId = 'No doc ID informed yet';
I'm trying to change the value of this global variable inside my main function:
function generatePersonDatasheet() {
var target = createDuplicateDocument(template, docName);
var link = target.getUrl();
targetDocId = target.getId(); // <-------- HERE
if (theses == 1){
Logger.log("going to showList() ");
return showList();
}
showURL(docName, link);
}
After that, I'm trying to acess the changed global variable value in a handler function:
function submit(e){
var numberOfItems = Number(e.parameter.checkbox_total);
var thesesArrays = [];
for(var i = 0; i < numberOfItems; i++){
if(e.parameter['checkbox_isChecked_'+i] == 'true'){
thesesArrays.push(fact_list[i]);
}
}
for (var i = 0; i < thesesArrays.length; i++){
var thesesId = thesesArrays[i][2];
var thesesType = thesesArrays[i][1];
importTheses(targetDocId, thesesId, thesesType); // <-----HERE
}
return UiApp.getActiveApplication().close();
}
function importTheses(targetDocId, thesesId, thesesType) {
var targetDoc = DocumentApp.openById(targetDocId);
var targetDocParagraphs = targetDoc.getParagraphs();
var targetDocElements = targetDocParagraphs.getNumChildren();
var thesesDoc = DocumentApp.openById(thesesId);
var thesesParagraphs = thesesDoc.getParagraphs();
var thesesElements = thesesDoc.getNumChildren();
var eltargetDoc=[];
var elTheses=[];
for( var j = 0; j < targetDocElements; ++j ) {
var targetDocElement = targetDoc.getChild(j);
eltargetDoc[j]=targetDocElement.getText();
if(el[j]== thesesType){
for( var k = 0; k < thesesParagraphs-1; ++k ) {
var thesesElement = thesesDoc.getChild(k);
elTheses[k] = thesesDoc.getText();
targetDoc.insertParagraph(j, elTheses[k]);
}
}
}
}
But, as long as I tryied to change the targetDocId, when it's use as argument to importTheses(targetDocId, thesesId, thesesType); it still has the value 'No doc ID informed yet', even I have changed it, as if the program had been run from the beginning. Is an alternative to this "reset to original value" behavior? Or I have to use scriptDB or ScriptProperties to store the changed value of the global variable?
解决方案 Each separate execution of a script is done in a new execution instance. Any variables defined outside of a block of code (aka "global" variables) are therefore unique for that instance. When a trigger function is invoked by an event, it runs in its own instance, and any global values it sets are visible only to that instance; another function that is invoked by a spreadsheet or document UI, for example, would have its very own version of that non-scoped object (global).
Definition and retrieval of targetDocId would be a good application of the Cache Service.note
function get_targetDocId () {
var cache = CacheService.getPublicCache();
var cached = cache.get("targetDocId");
if (cached != null) {
return cached;
}
var target = createDuplicateDocument(template, docName); /// Need to add handling for pre-existing document
var link = target.getUrl();
var contents = target.getId();
cache.put("targetDocId", contents, 1500); // cache for 25 minutes
return contents;
}
Now instead of trying to use a global variable, just call this function:
...
var targetDoc = DocumentApp.openById(get_targetDocId());
...
note Cache Service is one example of persistent storage available for Google Apps Script. The Properties Service was introduced after this answer was written, and is a much lighter-weight way to persist "global" variables between execution instances.
Observation: it appears that you're using a global (static) for tempate and docName, since there are no parameters for generatePersonDatasheet(). You could simply generate the targetDocId on the fly.
Bug: As it is written, get_targetDocId() will create a new copy of docName every time it needs to refresh the cache (15 mins). You should add handling for the possibility of a pre-existing file. (This is true of your existing onOpen() as well.)
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