Deletion of element from XML by specifying a condition

saralay · March 11th, 2013, 03:50 AM

Hi,

I want to delete a node from XML by specifying a condition as below...
input XML:
<Transmission>
<ItemMaster>
<Item>
<ItemId>111</ItemId>
<ItemName>I1</ItemName>
</Item>
<Item>
<ItemId>112</ItemId>
<ItemName>I2</ItemName>
</Item>
<Item>
<ItemId>113</ItemId>
<ItemName>I3</ItemName>
</Item>
</ItemMaster>
</Transmission>

if ItemId = '112'

then i want the Item node to be deleted from xml where ItemId=112

Output xml:

<transmission>
<ItemMaster>
<Item>
<ItemId>111</ItemId>
<ItemName>I1</ItemName>
</Item>
<Item>
<ItemId>113</ItemId>
<ItemName>I3</ItemName>
</Item>
</ItemMaster>
</Transmission>

Any body help me how to esolve this
Thanks in advance!!!

Thanks
Sarala

mhkay · March 11th, 2013, 04:31 AM

Create a stylesheet with two template rules.

(1) an "identity template which copies everything by default

Code:

<xsl:template match="*"><xsl:copy><xsl:apply-templates/></xsl:copy></xsl:template>

(2) a template rule to "not copy" (i.e. delete) the selected element

Code:

<xsl:template match="ItemId[.='112']"/>

saralay · March 11th, 2013, 04:53 AM

Thankyou for your reply Mhkay,

But the code which u have provided is not deleting the whole item node where itemId='112'.

The output when used the above code is as below...
<Transmission>
<ItemMaster>
<Item>
<ItemId>111</ItemId>
<ItemName>I1</ItemName>
</Item>
<Item>
<ItemName>I2</ItemName>
</Item><Item>
<ItemId>113</ItemId>
<ItemName>I3</ItemName>
</Item>
</ItemMaster>
</Transmission>

Thanks,
Sarala

mhkay · March 11th, 2013, 05:06 AM

Sorry, I made the mistake of giving you code rather than an explanation. I usually try to give an explanation, and leave you to write the code, because that way it forces you to try and understand the solution rather than just applying it blindly.

The design principle is exactly the same, you just need to change the pattern for the node being deleted from ItemId[.='112'] to Item[ItemId='112']

saralay · March 11th, 2013, 05:11 AM

Thanks Michael

,

If I have a many mutiple ItemId's which I need to delete from XML, what logic should I use?

Thanks in advance!!!

Sarala

mhkay · March 11th, 2013, 05:46 AM

Just use a match pattern that matches all the nodes you want to delete - or multiple template rules if you prefer.

saralay · March 11th, 2013, 06:12 AM

Hi Michael
thanks for your reply,

If I have xml like below...,
<Transmission>
<Location>
<LocId>L1</LocId>
<LocName>LOCa</LocName>
</Location>
<Location>
<LocId>L2</LocId>
<LocName>LOCb</LocName>
</Location>
<ItemMaster>
<Item>
<ItemId>111</ItemId>
<ItemName>I1</ItemName>
</Item>
<Item>
<ItemId>112</ItemId>
<ItemName>I2</ItemName>
</Item>
<Item>
<ItemId>113</ItemId>
<ItemName>I3</ItemName>
</Item>
</ItemMaster>
<Items>
<ItemId>111</ItemId>
<ItemId>112</ItemId>
</Items>
</Transmission>

I have to traverse through Transmission/Items where it should go for all the ItemId in Items and delete the Item node from ItemMaster where ItemMaster/Item/ItemId=Items/ItemId

output xml will be as follows......
<Transmission>
<Location>
<LocId>L1</LocId>
<LocName>LOCa</LocName>
</Location>
<Location>
<LocId>L2</LocId>
<LocName>LOCb</LocName>
</Location>
<ItemMaster>
<Item>
<ItemId>113</ItemId>
<ItemName>I3</ItemName>
</Item>
</ItemMaster>
<Items>
<ItemId>111</ItemId>
<ItemId>112</ItemId>
</Items>
</Transmission>

Hope I am clear with my requirement...
please help me to resolve this
Thanks in advance!!!!!!

Sarala

Martin Honnen · March 11th, 2013, 07:17 AM

Well your own post shows the paths you need so use the identity transformation template as already suggested, then add a template

Code:

<xsl:template match="ItemMaster/Item[ItemId = /Transmission/Items/ItemId]"/>

With XSLT 2.0 and for efficiency I would use a key however:

Code:

<xsl:stylesheet
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  version="2.0">
  
<xsl:strip-space elements="*"/>
<xsl:output indent="yes"/>
  
<xsl:variable name="ids-to-be-deleted" select="/Transmission/Items/ItemId"/>

<xsl:key name="to-be-deleted" match="ItemMaster/Item" use="ItemId"/>

<xsl:template match="@* | node()">
  <xsl:copy>
    <xsl:apply-templates select="@* | node()"/>
  </xsl:copy>
</xsl:template>

<xsl:template match="key('to-be-deleted', $ids-to-be-deleted)"/>

</xsl:stylesheet>

saralay · March 11th, 2013, 07:27 AM

Hi Martin,

Thanks for your reply....

It is giving the whole source file as it is with out deleting the Item nodes.

Thanks
Sarala

Martin Honnen · March 11th, 2013, 07:42 AM

When I apply the code

Code:

xsl:stylesheet
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  version="2.0">
  
<xsl:strip-space elements="*"/>
<xsl:output indent="yes"/>
  
<xsl:variable name="ids-to-be-deleted" select="/Transmission/Items/ItemId"/>

<xsl:key name="to-be-deleted" match="ItemMaster/Item" use="ItemId"/>

<xsl:template match="@* | node()">
  <xsl:copy>
    <xsl:apply-templates select="@* | node()"/>
  </xsl:copy>
</xsl:template>

<xsl:template match="key('to-be-deleted', $ids-to-be-deleted)"/>

</xsl:stylesheet>

to the input

Code:

<Transmission>
  <Location>
    <LocId>L1</LocId>
    <LocName>LOCa</LocName>
  </Location>
  <Location>
    <LocId>L2</LocId>
    <LocName>LOCb</LocName>
  </Location>
  <ItemMaster>
    <Item>
      <ItemId>111</ItemId>
      <ItemName>I1</ItemName>
    </Item>
    <Item>
      <ItemId>112</ItemId>
      <ItemName>I2</ItemName>
    </Item>
    <Item>
      <ItemId>113</ItemId>
      <ItemName>I3</ItemName>
    </Item>
  </ItemMaster>
  <Items>
    <ItemId>111</ItemId>
    <ItemId>112</ItemId>
  </Items>
</Transmission>

with Saxon 9.4 I get the output

Code:

<Transmission>
   <Location>
      <LocId>L1</LocId>
      <LocName>LOCa</LocName>
   </Location>
   <Location>
      <LocId>L2</LocId>
      <LocName>LOCb</LocName>
   </Location>
   <ItemMaster>
      <Item>
         <ItemId>113</ItemId>
         <ItemName>I3</ItemName>
      </Item>
   </ItemMaster>
   <Items>
      <ItemId>111</ItemId>
      <ItemId>112</ItemId>
   </Items>
</Transmission>

So inside ItemMaster some Item elements have been removed.