836
votes

How do I comment out a block of tags in XML?

I.e. How can I comment out <staticText> and everything inside it, in the code below?

  <detail>
    <band height="20">
      <staticText>
        <reportElement x="180" y="0" width="200" height="20"/>
        <text><![CDATA[Hello World!]]></text>
      </staticText>
    </band>
  </detail>

I could use <!-- staticText--> but that's just for single tags (as what I know), like // in Java and C. I would like something more like how /** comment **/ can be used in Java and C, so I can comment out longer blocks of XML code.

8
You should know that comments within an xml file are considered nodes of XmlComment type. So if you load the xml file those comments nodes are going to get loaded and it is up to you to avoid them or filter them when parsing the loaded content.El Bayames
XML comments are similar to comments in HTML.Somnath Muluk

8 Answers

1199
votes

You can use that style of comment across multiple lines (which exists also in HTML)

<detail>
    <band height="20">
    <!--
      Hello,
         I am a multi-line XML comment
         <staticText>
            <reportElement x="180" y="0" width="200" height="20"/>
            <text><![CDATA[Hello World!]]></text>
          </staticText>
      -->
     </band>
</detail>
188
votes

You can wrap the text with a non-existing processing-instruction, e.g.:

<detail>
<?ignore
  <band height="20">
    <staticText>
      <reportElement x="180" y="0" width="200" height="20"/>
      <text><![CDATA[Hello World!]]></text>
    </staticText>
  </band>
?>
</detail>

Nested processing instructions are not allowed and '?>' ends the processing instruction (see http://www.w3.org/TR/REC-xml/#sec-pi)

147
votes

If you ask, because you got errors with the <!-- --> syntax, it's most likely the CDATA section (and there the ]]> part), that then lies in the middle of the comment. It should not make a difference, but ideal and real world can be quite a bit apart, sometimes (especially when it comes to XML processing).

Try to change the ]]>, too:

  <!--detail>
    <band height="20">
      <staticText>
        <reportElement x="180" y="0" width="200" height="20"/>
        <text><![CDATA[Hello World!]--><!--]></text>
      </staticText>
    </band>
  </detail-->

Another thing, that comes to mind: If the content of your XML somewhere contains two hyphens, the comment immediately ends there:

<!-- <a> This is strange -- but true!</a> -->
--------------------------^ comment ends here

That's quite a common pitfall. It's inherited from the way SGML handles comments. (Read the XML spec on this topic)

50
votes

Actually, you can use the <!--...--> format with multi-lines or tags:

<!--
  ...
  ...
  ...
-->
29
votes

Here for commenting we have to write like below:

<!-- Your comment here -->

Shortcuts for IntelliJ Idea and Eclipse

For Windows & Linux:

Shortcut for Commenting a single line:

Ctrl + /

Shortcut for Commenting multiple lines:

Ctrl + Shift + /

For Mac:

Shortcut for Commenting a single line:

cmnd + /

Shortcut for Commenting multiple lines:

cmnd + Shift + /

One thing you have to keep in mind that, you can't comment an attribute of an XML tag. For Example:

<TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    <!--android:text="Hello.."-->
    android:textStyle="bold" />

Here, TextView is a XML Tag and text is an attribute of that tag. You can't comment attributes of an XML Tag. You have to comment the full XML Tag. For Example:

<!--<TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="Hello.."
    android:textStyle="bold" />-->
11
votes

You can easily comment out the data using this:

<!-- 
 <data>
        <data-field1></data-field1>
        <data-field2></data-field2>
        <data-field3></data-field3>
 </data>
-->

method of commenting in xml.

2
votes

Syntax for XML : <!--Your comment-->

eg.

   <?xml version = "1.0" encoding = "UTF-8" ?>
   <!--here is your comment :) -->
   <class_list>   
   <student>
   <name></name>
   <grade>A</grade>
   </student>
   </class_list>

XML Comments Rules

Comments cannot appear before XML declaration.
Comments may appear anywhere in a document.
Comments must not appear within attribute values.
Comments cannot be nested inside the other comments.
1
votes

In Notepad++ you can select few lines and use CTRL+Q which will automaticaly make block comments for selected lines.