查找字符串是否包含给定xml元素的正则表达式

Question

I have the following xml

<person>
    <id>1</id>
    <name>John</name>
    <phone>235 234</phone>
    <address>
        <street>1</street>
        <city>A</city>
        <state>B</state>
        <country>C</country>
    </address>
</person>

I transformed this xml into string and this is a dynamic xml. Some xml has all these elements and some not have the specified element and some xml has additional element.

Based on the xml string I want to write the regular expression to find whether the given element (as input) present in the string.

How to write regular expression for this?

Answer 1

All the comment writers are right. There are better methods than using a regular expression search to find out if an XML element contains a specified element or its tag.

But if you really want to do this task with a regular expression search, it is possible to use for your example:

<person>(?:(?!</person>)[\S\s])+<XXX\b(?:(?!</person>)[\S\s])+</person>

This expression matches everything from starting tag <person> to ending tag </person> if it contains <XXX whereby XXX is the element to find within element person .

Note: This regular expression works only if element person does not contain itself another person element and there is no CDATA section containing </person> or <person or <XXX .

The expression just checks if the starting tag for element XXX is found without a check for the ending tag as it is not clear from the question if all elements must be present with a starting and an ending tag or if some could be also empty elements in form <XXX /> .

For an explanation of this regular expression read my answer on Deleting duplicate values using find and replace in a text editor .