Let user omit elements with checkboxes?

[swsdam]

Thank you for even reading this...

I have an xml doc that feeds into html. I am being passed the xml via asp.net. I have used xsl to create an html. Now I'm being asked to let the user omit which elements get copied to new xml (via another xsl?). I would like to present the xml elements to my user and let them select which elements to copy onto another xml doc by clicking a checkbox. Is this possible and how?

So far I am thiking maybe I should use xsl to create a form then use another xsl somehow copies the selected elements.

Or perhaps I should use ASP.NET to select which elements to write to xml in the first place. (Well IT would have to do that as I am not allowed to touch the ASP.NET).

Please provide sample code for using a checked checkbox to copy elements.

Original XML:

<peoples>
   <person>
     <name>Stan</name>
     <address>11 View St.</address>
     <city>Sometown</city>
     <state>CA</state>
     <zip>99999</zip>
     <phone>111-2222</phone>
     <email>[e-mail]</email>
   </person>
</peoples>

Possible Outcome:

<peoples>
   <person>
     <name>Stan</name>
     <phone>111-2222</phone>
   </person>
</peoples>

[jkmyoung]

For creating the form, you could something like:

<form name="elementFilter" action="html_form_action.asp" method="get">
  <xsl:for-each select="/peoples/person[1]/*">
    <input type="checkbox" name="{local-name()}" value="{local-name()}"/>
  </xsl:for-each>
</form>

Then when you receive the data from the submission, pass it to the xml accordingly.
Pseudocode: (since I don't know what processor you're using.)
foreach value sent in:
set xsl parameter with given name to true
end foreach

In your result xslt: (this could be dynamically generated too, if you don't know the names of the elements beforehand.)

<xsl:param name="name"/>
<xsl:param name="address"/>
<xsl:param name="city"/>
<xsl:param name="state"/>
<xsl:param name="zip"/>
<xsl:param name="phone"/>
<xsl:param name="email"/>

Use templates to make copying easier:

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

Then in each of the corresponding templates:

<xsl:template match="name">
  <xsl:if test="$name != ''">
    <xsl:copy-of select="."/>
  </xsl:if>
</xsl:template>

Note, the code written assumes a flat, table-like structure to your data. It can be modified if your data is imbricated.

[swsdam]

Thanks you so much for your help jkmyoung!

I have only gotten as far as passing the values to the form. We are using the .NET Framework XML core classes (MSXML?) to process the xsl.

But I have a question about the value in the initial form. So far I've modified the form so it gives the user a preview of the values in the form.

    <xsl:for-each select="/peoples/person">
        <p>
        <xsl:for-each select="*">
            <input type="checkbox" name="{local-name()}" value="{local-name()}" checked="checked" />
            <label for="{local-name()}">
            Print <xsl:value-of select="local-name()" />: 
                       <xsl:value-of select="." /> </label><br />
        </xsl:for-each>
        </p>
    </xsl:for-each>
 

But I notice the the value is not the value in the original xml. Where Does the value for the parameter pull the value from the original xml? Is this happening when I set the xsl parameters in the processor? Is there something I'm not understanding?

Also, would approach still work with elements and attributes?

For creating the form, you could something like:

<form name="elementFilter" action="html_form_action.asp" method="get">
  <xsl:for-each select="/peoples/person[1]/*">
    <input type="checkbox" name="{local-name()}" value="{local-name()}"/>
  </xsl:for-each>
</form>

Then when you receive the data from the submission, pass it to the xml accordingly.
Pseudocode: (since I don't know what processor you're using.)
foreach value sent in:
set xsl parameter with given name to true
end foreach

In your result xslt: (this could be dynamically generated too, if you don't know the names of the elements beforehand.)

<xsl:param name="name"/>
<xsl:param name="address"/>
<xsl:param name="city"/>
<xsl:param name="state"/>
<xsl:param name="zip"/>
<xsl:param name="phone"/>
<xsl:param name="email"/>

[jkmyoung]

What you're doing looks like it should retrieve the original values. I'd check the filepaths, eg the place where you are loading the original xml to be processed. Parameters shouldn't affect this at all.

On a side note, do you only ever have one person node?

[swsdam]

What you're doing looks like it should retrieve the original values. I'd check the filepaths, eg the place where you are loading the original xml to be processed. Parameters shouldn't affect this at all.

On a side note, do you only ever have one person node?

Let me ask another way. Am I passing the values to the parameters when I post the form (and the check boxes) to the processing asp page? Otherwise, I'm not sure how the value gets assigned to the parameter. I looked up everything I could about parameters and I did not find a way to set a parameter to true. I assume you mean for me to define it in the XSL.

Can you tell me more about is happening when the form data gets passed to the processor? Or maybe just why I'm setting the parameter to tru?

Pseudocode: (since I don't know what processor you're using.)

foreach value sent in:
set xsl parameter with given name to true
end foreach

And no there are multiple people nodes. Which is why I'm adding a <p> in between the for statement.

[jkmyoung]

The 'true' could really be any value.
Just set it to anything which isn't the empty string, so that your xslt recognizes that the parameter has been set.

[swsdam]

What do you mean pass the results back to the xml? And can the pseudo code be accomplished with MSXML and/or ASP.NET?

Originally Posted by jkmyoung
Pseudocode: (since I don't know what processor you're using.)
Code: ( text )
1. foreach value sent in:
2. set xsl parameter with given name to true
3. end foreach

[jkmyoung]

What do you mean pass the results back to the xml? And can the pseudo code be accomplished with MSXML and/or ASP.NET?

I realized over the weekend a much simpler method.
Instead of creating a complicated parameter passing scheme, you could instead create a secondary xml.

Based on the checkboxes, create a secondary xml like so:

<root>
    <element>peoples</element>
    <element>person</element>
    <element>name</element>
    <element>phone</element>
</root>

(copy.xml)

Then, apply this xsl to your original xml, referencing copy.xml so that you know which nodes to copy over.

<xsl:variable name="copy" select="document('copy.xml')/root/element"/>
<xsl:template match="*">
    <xsl:if test="$copy[. = local-name(current())]">
    <xsl:copy>
        <xsl:apply-templates/>
    </xsl:copy>
    </xsl:if>
</xsl:template>

This should give you this as output:

<peoples>
    <person>
        <name>Stan</name>
        <phone>111-2222</phone>
    </person>
</peoples>

I hope this solution is easier to implement and get your head around.

[swsdam]

I realized over the weekend a much simpler method.
Instead of creating a complicated parameter passing scheme, you could instead create a secondary xml.

...

I hope this solution is easier to implement and get your head around.

Yes. This is much easier for me to understand and implement. Thanks so much! You Rock!