Скачать или смотреть Extracting Distinct Names of Child Nodes in XSLT

Learn how to efficiently retrieve and count distinct child node names using XSLT with examples.
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Extracting Distinct Names of Child Nodes in XSLT

When working with XML data, it’s often useful to extract distinct child node names to understand the structure and elements within your dataset. This is particularly essential in the realms of data transformation, reporting, and analysis using XSLT (Extensible Stylesheet Language Transformations). In this guide, we will dive into how to accomplish this by leveraging XSLT's powerful capabilities.

Understanding the Problem

Imagine you have an XML document containing multiple <mensagem> nodes, each with various child elements, as shown in the following snippet:

[[See Video to Reveal this Text or Code Snippet]]

In this XML structure, you want to extract distinct names of all child nodes under each <mensagem>, such as inicioAtividade, fimAtividade, and others. The challenge lies in obtaining these names efficiently, especially when aiming for distinct values only.

The Solution

Distinct Names Extraction

To retrieve distinct names of child nodes in XSLT, you can utilize the following expression:

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Explanation:

mensagem/* selects all child elements under each <mensagem> node.

name() fetches the name of each child node.

distinct-values() ensures that only unique names are retained.

separator=", " defines how you'll separate the names in the output.

Output:
Running this code segment will yield the distinct child node names as follows:

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Counting Occurrences of Each Distinct Name

If you want to go a step further and count how many times each distinct child name appears, you can use the following XSLT template:

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How it works:

for-each-group is used to group the child nodes by their names.

count(current-group()) counts the number of occurrences for each grouped name.

current-grouping-key() provides the actual name of the node.

Output:
With this template, you would generate output like the following, providing both the name and the count:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

Extracting distinct child node names from an XML structure can be seamlessly achieved with XSLT, whether it’s merely for listing names or counting their occurrences. By employing distinct-values() and for-each-group effectively, you can tailor your data manipulation and reporting needs to suit your specific requirements.

Feel free to experiment with these snippets in your XSLT processor and take advantage of these powerful functions to enhance your XML handling capabilities!