How to extract strings from nodes having same name in xslt

Question

I have 4 similar nodes with 4 different values. For example, I have the below values.

<sample>
        <a>123</a>
        <a>45</a>
        <a>67</a>
        <a>890</a>
</sample>

I need to check the length of each node and if its less than 3, then leading zeroes should be appended like below.

<sample>
        <a>123</a>
        <a>045</a>
        <a>067</a>
        <a>890</a>
</sample>

After appending leading zeroes, I need to concatenate all the values together and pass it as a single string.

<a>123045067890</a>

Please provide an optimum solution.

This is trivial to do in XSLT: just use the `format-number()` function in a `xsl:for-each` instruction. — michael.hor257k, Apr 24 '17 at 08:12
@michael.hor257k I have used xsl:for-each command. But when I use that, only the first tag gets taken into account and not the second and other. — Black Pearl, Apr 24 '17 at 09:11
This is the code I have tried. Please put your thoughts. ERROR — Black Pearl, Apr 24 '17 at 09:13

score 1 · Answer 1 · answered Apr 24 '17 at 07:54

here's one approach using XPath:

string xml = @"
    <sample>
        <a>123</a>
        <a>45</a>
        <a>67</a>
        <a>890</a>
    </sample>
";

//load xml
XmlDocument xdoc = new XmlDocument();
xdoc.LoadXml(xml);

//get all <a> nodes and cast them to List<XmlNode>
var nodes = xdoc.SelectNodes("sample/a")
    .Cast<XmlNode>().ToList();

//iterate through each node and append leading zeroes until length is 3 chars
nodes.ForEach(n => n.InnerText = n.InnerText.PadLeft(3, '0'));
//join all values and add tags to beginning and the end
string concatenatedValues = "<a>" + string.Join("", nodes.Select(x => x.InnerText).ToArray()) + "</a>";

score 1 · Accepted Answer · answered Apr 24 '17 at 10:30

The following stylesheet:

XSLT 1.0

<xsl:stylesheet version="1.0" 
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml" version="1.0" encoding="UTF-8" indent="yes"/>
<xsl:strip-space elements="*"/>

<xsl:template match="sample">
    <a>
        <xsl:for-each select="a">
            <xsl:value-of select="format-number(., '000')" />
        </xsl:for-each>
    </a>
</xsl:template>

</xsl:stylesheet>

applied to your example input, returns:

<?xml version="1.0" encoding="UTF-8"?>
<a>123045067890</a>

daniell89 · Answer 3 · 2017-04-24T08:32:05.540

0

You can try this:

string xml = @"<sample>
                        <a>123</a>
                        <a>45</a>
                        <a>67</a>
                        <a>890</a>
                    </sample>";

XDocument xmlDoc = XDocument.Parse(xml);
int value = 0;
StringBuilder errorsSb = new StringBuilder();
List<string> a_Nodes = new List<string>();

xmlDoc.Descendants("a").Select(x => x.Value).ToList().ForEach(x =>
{
     if (int.TryParse(x, out value))
          a_Nodes.Add(value.ToString("D3"));
     else
          errorsSb.AppendLine($"Value {value} is not a number");
     });

     string res = String.Join(string.Empty, a_Nodes);
     if (!string.IsNullOrWhiteSpace(errorsSb.ToString()))
     {
          // handle errors
     }
}

edited Apr 24 '17 at 08:32

answered Apr 24 '17 at 08:01

daniell89

1,832
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Your code would cause exceptions if non-numeric values are inside the `` tags due to the `int.Parse(x.Value)` – Cleptus Apr 24 '17 at 08:03
@bradbury9, so you think it is not good behawior? Better will be just add zeros to any text? Or just skip invalid entry...? I disagree with you. Exception will inform that something is wrong with xml. And catching exception is not a part of the question. – daniell89 Apr 24 '17 at 08:09
Exceptions is a so heavy method to control input. Unhandled exceptions? IMHO should not happen. In this case you could use schemas (heavier), a foreach with int32.TryParse (lighter) – Cleptus Apr 24 '17 at 08:13
A `foreach` should perform the same as the `Select` and a `TryParse` would perform better than a try-catch + Parse http://stackoverflow.com/questions/150114/parsing-performance-if-tryparse-try-catch – Cleptus Apr 24 '17 at 08:27
@bradbury9 daniell's answer isn't necessarily bad; OP did't specify which kind of data is expected in those nodes and daniell assumed it's int, without exceptions. To get better answer, OP should define his/hers question with a bit more details. Anyhow, `TryParse` is better approach. – Nino Apr 24 '17 at 08:33
@bradbury9, Ok, I've just corrected my answer. Thanks – daniell89 Apr 24 '17 at 08:33
@Nino Agree on your comment, personally I deeply disliked the `Int32.Parse`, hence my observation and downvote. Just removed the downvote after the edit. – Cleptus Apr 24 '17 at 10:22

How to extract strings from nodes having same name in xslt

3 Answers3