reading an XML and outputing an RSS feed.

[googletired]

Hello,

I've been working on this for a days and getting frustrated. Basically i want read a master xml file that references many other xml files and use this information to output an RSS Feed.

File to reference. this file is usally quite large and has many categories so it needs to be able to read each category and output a channel then item contents for each article id in the catecory.

<?xml version="1.0" encoding="utf-8"?>
<vol_issue vol_issue_id="idname">
 <description>text here</description>
 <language>en</language>
 <type>print</type>
 <xmlfilename>filename.xml</xmlfilename>
 <cdfilename>filename.xml</cdfilename>
 <category category_id="2">
  <sort_order>2</sort_order>
  <article article_id="filename"/>
  <article article_id="filename"/>
  <article article_id="filename"/>
  <article article_id="filename"/>
  <article article_id="filename"/>
  <article article_id="filename"/>
  <article article_id="filename"/>
  <article article_id="filename"/>
  <article article_id="filename"/>
 </category>
</volissue>

this is the XSL i am building to handle the operation, at this point all it does is insert the top 6 lines of the above .xml which i do not even need.

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml" encoding="windows-1252" omit-xml-declaration="yes"/>
<xsl:param name="type">print</xsl:param>
    <xsl:param name="vol">200304</xsl:param>
    <xsl:param name="cat">2</xsl:param>
    <xsl:param name="articleid">12345</xsl:param>
<xsl:variable name="OpenCDATASection"><![CDATA[<![]]><![CDATA[CDATA[]]></xsl:variable>
<xsl:variable name="CloseCDATASection"><![CDATA[]]]]><![CDATA[>]]></xsl:variable>
<xsl:variable name="cat_description" select="document('../articles/categories.xml')/main/category[@category_id = $cat]/description"/>
<xsl:template match="feeds/feed">
<rss version="2.0">
<xsl:for-each select="@category_id">
    <channel>
        <title><xsl:variable name="catid" select="@category_id"/></title>
        <description><xsl:value-of select="description"/></description>
        <link></link>
        <lastBuildDate><xsl:value-of select="@feeddate"/></lastBuildDate>
 
    <xsl:variable name="feed_articles" select="document('../articles/') "/>
 
    <xsl:for-each select="article">
 
        <xsl:variable name="articleid" select="."/>
        <xsl:variable name="article" select="document(concat('../articles/', $articleid, '.xml'))"/>
 
 
 
            <item>
                <title><xsl:value-of select="$article/article/headline"/></title>
                <description><xsl:value-of select="$article/article/blurb"/></description>
                <link>http://linkhere?articleID=<xsl:value-of select="$articleid"/></link>
 
            </item>
            </xsl:for-each>
 
</channel>
</xsl:for-each>
</rss>
</xsl:template>
</xsl:stylesheet>

Hope you can help.

[jkmyoung]

I can see several problems with your xslt and xpath. To start with:
1. For-each context problem

<xsl:template match="feeds/feed">
...
<xsl:for-each select="@category_id">
 

This changes the context to the category_id attribute node.
The title doesn't make sense, nor does the description.
I would remove the for-each altogether.

2. <xsl:variable name="feed_articles" select="document('../articles/') "/>
This is a directory, not an xml file, and would cause problems.

3. <xsl:variable name="articleid" select="."/>
Don't you want <xsl:variable name="articleid" select="@articleid"/> ?

Possible other problem:
-<xsl:template match="feeds/feed">
Do you only have one feed element? Where is your feed element? Perhaps this should be <xsl:template match="/vol_issue"> instead?

Where are your articles xml files located?

[googletired]

I can see several problems with your xslt and xpath. To start with:
1. For-each context problem

<xsl:template match="feeds/feed">
...
<xsl:for-each select="@category_id">
 

This changes the context to the category_id attribute node.
The title doesn't make sense, nor does the description.
I would remove the for-each altogether.

2. <xsl:variable name="feed_articles" select="document('../articles/') "/>
This is a directory, not an xml file, and would cause problems.

3. <xsl:variable name="articleid" select="."/>
Don't you want <xsl:variable name="articleid" select="@articleid"/> ?

Possible other problem:
-<xsl:template match="feeds/feed">
Do you only have one feed element? Where is your feed element? Perhaps this should be <xsl:template match="/vol_issue"> instead?

Where are your articles xml files located?

Thanks for the reply i will work through the problem areas that you have pointed out.

But i am still not 100% sure on how to make it read through the master list and treat each category as a seperate RSS channel.

Vol_issue if just another master file that holds 4 or 5 other master files and inside those files is what is contained with above .xml in mt first post.

[googletired]

Ok, mayeb this will give you a better understanding of what i need,

I have to read all the below information and export a single RSS file.

So it would be

<rss>

<channel> (treat each category id as a channel)

contents
<item>
contents
</item>
</channel>

<channel>
Contents
<item>
contents
</item>
</channel>
ect ect ect.
</rss>

<?xml version="1.0" encoding="utf-8"?>
<vol_issue vol_issue_id="200712">
 <description>December</description>
 <language>en</language>
 <type>print</type>
 <xmlfilename>en_print_200712.xml</xmlfilename>
 <cdfilename>cd_en_print_200712.xml</cdfilename>
 <category category_id="2">
  <sort_order>2</sort_order>
  <article article_id="47106"/>
  <article article_id="47032"/>
  <article article_id="47015"/>
  <article article_id="46852"/>
  <article article_id="46828"/>
  <article article_id="46827"/>
  <article article_id="46826"/>
  <article article_id="46825"/>
  <article article_id="46434"/>
 </category>
 <category category_id="72">
  <sort_order>7</sort_order>
  <article article_id="47179"/>
  <article article_id="47178"/>
  <article article_id="47177"/>
  <article article_id="47176"/>
  <article article_id="47175"/>
  <article article_id="47033"/>
  <article article_id="47032"/>
  <article article_id="47031"/>
  <article article_id="46945"/>
  <article article_id="46944"/>
  <article article_id="46943"/>
  <article article_id="46929"/>
  <article article_id="46928"/>
  <article article_id="46927"/>
  <article article_id="46781"/>
  <article article_id="46780"/>
  <article article_id="46779"/>
  <article article_id="46767"/>
  <article article_id="46766"/>
  <article article_id="46765"/>
  <article article_id="46764"/>
  <article article_id="46763"/>
  <article article_id="46621"/>
  <article article_id="46617"/>
  <article article_id="46601"/>
  <article article_id="46592"/>
  <article article_id="46591"/>
  <article article_id="46590"/>
  <article article_id="46589"/>
  <article article_id="46588"/>
  <article article_id="46587"/>
  <article article_id="46586"/>
  <article article_id="46585"/>
  <article article_id="46457"/>
  <article article_id="46456"/>
  <article article_id="46455"/>
  <article article_id="46433"/>
  <article article_id="46419"/>
  <article article_id="46418"/>
  <article article_id="46417"/>
  <article article_id="46416"/>
 </category>
 <category category_id="5">
  <sort_order>10</sort_order>
  <article article_id="47206"/>
  <article article_id="46822"/>
  <article article_id="46821"/>
  <article article_id="46490"/>
 </category>
 <category category_id="6">
  <sort_order>11</sort_order>
  <article article_id="46976"/>
  <article article_id="46975"/>
  <article article_id="46945"/>
  <article article_id="46944"/>
  <article article_id="46943"/>
  <article article_id="46639"/>
  <article article_id="46638"/>
  <article article_id="46637"/>
  <article article_id="46489"/>
 </category>
 <category category_id="7">
  <sort_order>12</sort_order>
  <article article_id="46453"/>
  <article article_id="46452"/>
 </category>
 <category category_id="8">
  <sort_order>13</sort_order>
  <article article_id="47208"/>
  <article article_id="47206"/>
  <article article_id="46685"/>
  <article article_id="46638"/>
  <article article_id="46630"/>
  <article article_id="46491"/>
  <article article_id="46490"/>
  <article article_id="46489"/>
  <article article_id="46475"/>
  <article article_id="46432"/>
 </category>
 <category category_id="9">
  <sort_order>14</sort_order>
  <article article_id="47142"/>
  <article article_id="47141"/>
  <article article_id="46939"/>
  <article article_id="46687"/>
  <article article_id="46518"/>
  <article article_id="46517"/>
  <article article_id="46445"/>
  <article article_id="46444"/>
 </category>
</vol_issue>
 

[jkmyoung]

Let's go about this using the template method.
You have one main node, vol_issue. Use this to create the main node in your result, and use apply-templates to create the rest of what you need. I also notice you have sort order in your categories, so we'll use that as well.

<xsl:template match="vol_issue"><!-- main template -->
  <rss version="2.0">
    <xsl:apply-templates select="category">
       <xsl:sort select="sort_order"/>
    </xsl:apply-templates>
  </rss>
</xsl:template>

You said:

(treat each category id as a channel)

So, assuming each category has a different id, we create a template for it.

<xsl:template match="category">
  <channel>
      <title><xsl:variable name="catid" select="@category_id"/></title>
      <link></link>

Unfortunately, the description is in the root node. So, we use .. to go up one level. Is feed date vol_issue_id?

    <description><xsl:value-of select="..\description"/></description>
    <feed_date><xsl:value-of select="..\@vol_issue_id"/></feed_date>
    <xsl:apply-templates select="article"> 
</xsl:template>

We've also included an apply-templates on the article, so now let's finish up with the article template.

<xsl:template match="article">
  <xsl:variable name="article" select="document(concat('../articles/', @article_id, '.xml'))"/>
  <item>
    <title><xsl:value-of select="$article/article/headline"/></title>
    <description><xsl:value-of select="$article/article/blurb"/></description>
    <link>http://linkhere?articleID=<xsl:value-of select="@article_id"/></link>
  </item>
</xsl:template>

I hope breaking it up into templates makes it easier to understand.

[googletired]

I hope breaking it up into templates makes it easier to understand.

Thanks again for the reply, yes it does make more sense that way,

Unfortunately, the description is in the root node. So, we use .. to go up one level. Is feed date vol_issue_id?

the vol_issue_id is the file that will be referenced to build the RSS, so on my asp page i select which issue to build the RSS from. The feed date can be any date.


Thanks again.

[googletired]

Ok all is well now with the exception of 1 item, i need to remove duplicates filenames in the output

so if <article article_id="47208"/> appears more than once in the vol_issue i don't want to write it more than once in the outputed XML.

[jkmyoung]

Within the same channel, or not?

<xsl:template match="article">
  <xsl:if test="not(preceding-sibling::article[@article_id = current()/@article_id])">
 

If the parent node doesn't matter, then use preceding:: instead of preceding-sibling::

[googletired]

Within the same channel, or not?

<xsl:template match="article">
  <xsl:if test="not(preceding-sibling::article[@article_id = current()/@article_id])">
 

If the parent node doesn't matter, then use preceding:: instead of preceding-sibling::

Thanks for all the help things are working they i need it to now.

[googletired]

ok i have made a slight error, i need to refernce the channel description from yet another .xml we will call it categories.xml

<main>
 <category category_id="00">
  <description>text here</description>  <--channel description to pull.
<cd_folder></cd_folder>
  <incl_in_reg></incl_in_reg>
  <sort_order></sort_order>
  <language></language>
  <image_filename></image_filename>
 </category>
 

Any thoughts?

[jkmyoung]

Ok, let's say you have a category in variable $category
To access the other document, we use the document() function.

eg.
<xsl:value-of select="document('category.xml')//category[@category_id=$category]/description"/>

[googletired]

Ah thank you, //category is the step i was missing.

Thanks again you are the best.