CODEWITHSUNDEEP
javapythondomjython
Ericson Willians
Ericson Willians

Reputation: 7845

Is there a way to check if a tag name exists in a Document? (DOM - Jython)

Here's my code:

'''
Created on 27/05/2015
@author: Rederick Deathwill
'''

from java.io import File
from java.io import IOException
from javax.xml.parsers import DocumentBuilder
from javax.xml.parsers import DocumentBuilderFactory
from org.w3c.dom import Document
from org.w3c.dom import Element
from org.w3c.dom import Node
from org.w3c.dom import NodeList
from org.xml.sax import SAXException

class JXLLoader():

    def __init__(self, fileName):  
        self.fileName = fileName
        self.file = File(self.fileName)
        self.dbFactory = DocumentBuilderFactory.newInstance()
        self.dBuilder = self.dbFactory.newDocumentBuilder()
        self.doc = self.dBuilder.parse(self.file)
        self.doc.getDocumentElement().normalize()

class JXLReader(JXLLoader):

    def __init__(self, fileName):
        JXLLoader.__init__(self, fileName)
        self.mainNodeList = self.doc.getElementsByTagName("main") # Here <<

if __name__ == '__main__':

    jxl = JXLReader("x.xml")
    print(jxl.mainNodeList)

    for i in range(jxl.mainNodeList.getLength()):
        node = jxl.mainNodeList.item(i)
        if (node.getNodeType() == Node.ELEMENT_NODE):
            e = node 
            print(e.getElementsByTagName("value").item(0).getTextContent())

Is there a way to check if the "TagName" exists within the Document object? I don't know how to check if the tag "main" is not present. For example:

The result of that print(jxl.mainNodeList) is:

com.sun.org.apache.xerces.internal.dom.DeepNodeListImpl@58a63629

Nevertheless, if I do this with a tag that does not exist:

self.mainNodeList = self.doc.getElementsByTagName("maix")

The result when I print is an address/object just like that one (Instead of a null / None or something). The point is, how am I going to know if "< main >< / main >" is really in the Document so that I can raise an Exception in case it isn't?

Here's the XML:

<?xml version="1.0" encoding="UTF-8"?>
<main>
    <value>100</value>
    <name>Rederick Deathwill</name>
</main>

EDIT: Also, I've checked the docs. There's not method like "hasTagName()".

Upvotes: 1

Views: 2370

Answers (1)

Dan D.
Dan D.

Reputation: 74655

Check the length of the return value of the getElementsByTagName call.

If self.mainNodeList.getLength() == 0 then the getElementsByTagName call found nothing.

Upvotes: 2

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