使用Selection的RangeElements获取Google文档中的所有嵌套文本元素

Question

在与上述类似的文档中，我可以使用以下代码获取所有段落：

var paras = body.getParagraphs();

请注意，上面的代码不仅返回顶级段落，而且还返回ListItem，Table等内部的所有子级段落。

如何在选定范围内做同样的事情？以下代码仅返回顶级元素。

const selection = DocumentApp.getActiveDocument().getSelection();
var rangeElements = selection.getRangeElements();

例如，上表包含9个非空的段落，如果要选择它们，我想一一处理它们。

我要实现的目标类似于通过尽可能保留格式，表格，列表项等来翻译所选内容中的文本。

Answer 1

.getRangeElements()返回一个RangeElements的数组。范围元素是一个包装器对象，用于帮助我们处理部分选择。我们可以在此数组中的每个项目上调用.getElement()，以获取Element object，这是一个非常通用对象，几乎可以表示任何Google文档。 Elements有一个.getType()方法，该方法返回一个ElementType枚举；其中有很多！

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让我们使用到目前为止所了解的信息来查看Google文档中可能的类型（以created one similar to yours (img)为例）

function selectionHasWhichTypes() {
  var doc = DocumentApp.getActiveDocument();
  var selection = doc.getSelection();
  var rangeElems = selection.getRangeElements();

  rangeElems.forEach(function(elem){
    var elem = elem.getElement();

    Logger.log(elem.getType());
  });
}

//Logger OUTPUT:
PARAGRAPH
PARAGRAPH
PARAGRAPH
PARAGRAPH
PARAGRAPH
LIST_ITEM
LIST_ITEM
LIST_ITEM
PARAGRAPH
PARAGRAPH
PARAGRAPH
TABLE
PARAGRAPH

啊哈！看来我们现在只需要处理PARAGRAPH，LIST_ITEM和TABLE ElementTypes ，但也请记住他们的孩子（我们会发现这是5个可以生孩子的3个）。这听起来像是递归函数的工作，它将不断地挖掘子元素，直到我们找到并处理所有子元素为止。

---

因此，我们尝试一下。下一部分可能看起来令人困惑，但本质上是要找到一个元素，检查它是否有子元素，然后查看那些元素以查看它们有孩子，等等。我们也要检查是否要获取新元素类型...

function selectionHasWhichTypes() {
  var doc = DocumentApp.getActiveDocument();
  var selection = doc.getSelection();
  var rangeElems = selection.getRangeElements();

  rangeElems.forEach(function(elem){
    var elem = elem.getElement();

    elemsHaveWhatChildElems(elem, elem.getType());

  });
}

function elemsHaveWhatChildElems(elem, typeChain){
  var elemType = elem.getType();
  if(elemType == "TABLE" || elemType == "LIST_ITEM" || elemType == "PARAGRAPH"){ //Lets see if element is one of our basic 3. If so they could have children.
    var numChildren = elem.getNumChildren(); //How many children are there?
    if(numChildren > 0){
      for(var i = 0; i < numChildren; i++){ //Let's go through them.
        var child = elem.getChild(i);
        elemsHaveWhatChildElems(child, typeChain + "." + child.getType()); //Recursion step to look for more children.
      }
    }else{
       Logger.log(typeChain); //Let's log the chain of Parent to Child elements.
    }
  }else{
    Logger.log("*" + typeChain); //Let's mark the new elemTypeChains we have not seen.
  }
}

//Logger OUTPUT:
*PARAGRAPH.TEXT
PARAGRAPH
*PARAGRAPH.HORIZONTAL_RULE
PARAGRAPH
*PARAGRAPH.TEXT
*LIST_ITEM.TEXT
*LIST_ITEM.TEXT
*LIST_ITEM.TEXT
PARAGRAPH
*PARAGRAPH.TEXT
PARAGRAPH
*TABLE.TABLE_ROW
*TABLE.TABLE_ROW
PARAGRAPH

好的，因此日志的每一行都是一串Elements及其子元素。我们有一些新ElementTypes （HORIZONTAL_RULE，TABLE_ROW和TEXT）。如果一条链只有Paragraph并且没有子链，则用'PARAGRAPH'表示。我们可以忽略它，因为它是空白行。我们也可以忽略HORIZONTAL_RULE，因为此显然不会包含文本。

如果我们已到达TEXT元素，则意味着我们可以像执行LIST_ITEM和PARAGRAPH一样执行我们的功能（即，对于OP来说就是翻译）。但是，我们仍然必须处理TableRow对象（其日志记录如下：TABLE.TABLE_ROW）。 类似于我们的主要3个元素，并且可以与我们的if(elemType == "TABLE" || elemType == "LIST_ITEM" || elemType == "PARAGRAPH")一起使用，后者更改为if(elemType == "TABLE" || elemType == "LIST_ITEM" || elemType == "PARAGRAPH" || elemType == "TABLE_ROW")。

这给我们链中的另一个新元素； TableCell（日志类似：TABLE.TABLE_ROW.TABLE_CELL），我们可以再次 将其添加到if语句中，使其成为：if(elemType == "TABLE" || elemType == "LIST_ITEM" || elemType == "PARAGRAPH" || elemType == "TABLE_ROW" || elemType == "TABLE_CELL")

---

是时候了解表元素类型了。

function selectionHasWhichtypeChains() {
  var doc = DocumentApp.getActiveDocument();
  var selection = doc.getSelection();
  var rangeElems = selection.getRangeElements();

  rangeElems.forEach(function(elem){
    var elem = elem.getElement();

    elemsHaveWhatChildElems(elem, elem.getType());

  });
}

function elemsHaveWhatChildElems(elem, typeChain){
  var elemType = elem.getType();
  if(elemType == "TABLE" || elemType == "LIST_ITEM" || elemType == "PARAGRAPH" || elemType == "TABLE_ROW" || elemType == "TABLE_CELL"){ //Lets see if element is one of our basic 5 if so they could have children.
    var numChildren = elem.getNumChildren(); //How many children are there?
    if(numChildren > 0){
      for(var i = 0; i < numChildren; i++){ //Let's go through them.
        var child = elem.getChild(i);
        elemsHaveWhatChildElems(child, typeChain + "." + child.getType()); //Recursion step to look for more children.
      }
    }else{
       Logger.log(typeChain); //Let's log the chain of Parent to Child elements.
    }
  }else{
    Logger.log("*" + typeChain); //Let's mark the new elemTypeChains we have not seen.
  }
}

//Logger OUTPUT:
*PARAGRAPH.TEXT
PARAGRAPH
*PARAGRAPH.HORIZONTAL_RULE
PARAGRAPH
*PARAGRAPH.TEXT
*LIST_ITEM.TEXT
*LIST_ITEM.TEXT
*LIST_ITEM.TEXT
PARAGRAPH
*PARAGRAPH.TEXT
PARAGRAPH
*TABLE.TABLE_ROW.TABLE_CELL.PARAGRAPH.TEXT
*TABLE.TABLE_ROW.TABLE_CELL.TABLE.TABLE_ROW.TABLE_CELL.PARAGRAPH.TEXT
*TABLE.TABLE_ROW.TABLE_CELL.TABLE.TABLE_ROW.TABLE_CELL.PARAGRAPH.TEXT
*TABLE.TABLE_ROW.TABLE_CELL.TABLE.TABLE_ROW.TABLE_CELL.PARAGRAPH.TEXT
*TABLE.TABLE_ROW.TABLE_CELL.TABLE.TABLE_ROW.TABLE_CELL.PARAGRAPH.TEXT
TABLE.TABLE_ROW.TABLE_CELL.PARAGRAPH
*TABLE.TABLE_ROW.TABLE_CELL.PARAGRAPH.TEXT
*TABLE.TABLE_ROW.TABLE_CELL.PARAGRAPH.HORIZONTAL_RULE
*TABLE.TABLE_ROW.TABLE_CELL.PARAGRAPH.TEXT
*TABLE.TABLE_ROW.TABLE_CELL.PARAGRAPH.TEXT
PARAGRAPH

---

太棒了！！我们深入到每个父元素的深处，并达到了 Text Element 或空白段！从这里我们可以稍微修改我们的代码，以添加我们要在维护文档结构的同时执行的功能：

function myFunction() {
  var doc = DocumentApp.getActiveDocument();
  var selection = doc.getSelection();
  var rangeElems = selection.getRangeElements(); //Get main Elements of selection

  rangeElems.forEach(function(elem){ //Let's rn through each to find ALL of their children.
    var elem = elem.getElement(); //We have an ElementType. Let's get the full element.
    getNestedTextElements(elem, elem.getType()); //Time to go down the rabbit hole.
  });
}

function getNestedTextElements(elem, typeChain){
  var elemType = elem.getType();
  if(elemType == "TABLE" || elemType == "LIST_ITEM" || elemType == "PARAGRAPH" || elemType == "TABLE_ROW" || elemType == "TABLE_CELL"){ //Lets see if element is one of our basic 5, if so they could have children.
    var numChildren = elem.getNumChildren(); //How many children are there?
    if(numChildren > 0){
      for(var i = 0; i < numChildren; i++){ //Let's go through them.
        var child = elem.getChild(i);
        getNestedTextElements(child, typeChain + "." + child.getType()); //Recursion step to look for more children.
      }
    }
  }else if(elemType == "TEXT"){
    //THIS IS WHERE WE CAN PERFORM OUR OPERATIONS ON THE TEXT ELEMENT
    var text = elem.getText();


  }else{
    Logger.log("*" + typeChain); //Let's log the new elem we dont deal with now - for future proofing.
  }
}

BOOM！完成。我知道这是一篇很长的文章，但是我将解决方案的每个部分分为几个部分，以帮助新的Apps Script编码人员理解选区的结构（我想是文档主体）以及如何在结构非常复杂（许多嵌套元素）时对其进行修改。 我真的希望这会有所帮助。如果有人看到可以改进的地方，请告诉我。

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作为OP的注意事项：请注意，这不一定要处理Element的部分选择，但是可以通过稍微修改第一个函数以检查isPartial()来轻松解决。在RangeElement上。