Question

I need to write a regex to match an element in a comma-separated list, ignoring whitespaces near ,.
For example:
elem1, elem2 ,elem3, elem4 ,elem5 ,elem6

Any of: elem1 elem2 elem3 elem4 elem5 elem6 should match.

The trailing comma (before end of line) is not allowed.

I tried this pattern:
pattern="(^|/,)\s*@{value}\s*(/,|$)"
but it doesn’t work. (False negative)

How can i do that pattern? What’s wrong in mine?

Thanks.

Answer 1

I found one solution:

The pattern is:

^(.+,\s*|\s*)@{value}(\s*|\s*,.+)$

An usage example is:

<macrodef name="csvcontains">
    <attribute name="value"/>
    <attribute name="list"/>
    <attribute name="propertyName"/>
    <attribute name="casesensitive" default="false"/>
    <sequential>
        <condition property="@{propertyName}" else="false">
            <or>
                <isset property="@{propertyName}"/>
                <matches string="@{list}" pattern="^(.+,\s*|\s*)@{value}(\s*|\s*,.+)$" casesensitive="@{casesensitive}"/>
            </or>
        </condition>
    </sequential>
</macrodef>