Question

For this problem, I will paste a sample stanza from the xml file I am working with, then discuss what I am trying to do with it.

I have an xml file with stanzas that look like this:

<mb model="460" rev="dba">
        <dmiblock block="Base Board Information">
                <dmiattr name="Manufacturer" value="MSI"/>
                <dmiattr name="Product Name" value="H61M-P25 (MS-7680)"/>
        </dmiblock>
        <dmiblock block="Memory Device">
                <dmiattr name="Bank Locator" value="A1_BANK0"/>
                <dmiattr name="Size" value="4096 MB"/>
        </dmiblock>
        <dmiblock block="Memory Device">
                <dmiattr name="Bank Locator" value="A1_BANK1"/>
                <dmiattr name="Size" value="No Module Installed"/>
        </dmiblock>
        <dmiblock block="Memory Device">
                <dmiattr name="Bank Locator" value="A1_BANK2"/>
                <dmiattr name="Size" value="No Module Installed"/>
        </dmiblock>
        <dmiblock block="Memory Device">
                <dmiattr name="Bank Locator" value="A1_BANK3"/>
                <dmiattr name="Size" value="No Module Installed"/>
        </dmiblock>

        <cpublock number="0">
                <cpuattr name="model name" value="Intel(R) Pentium(R) CPU G850 @ 2.90GHz"/>
        </cpublock>
        <cpublock number="1">
                <cpuattr name="model name" value="Intel(R) Pentium(R) CPU G850 @ 2.90GHz"/>
        </cpublock>
        <pciblock block="NIC">
                <pciattr string="Intel Corporation 82574L Gigabit Network Connection" number="2" />
        </pciblock>
        <blockblock block="model">
                <blockattr value="8GB SATA SSD T 3" number="1" />
                <blockattr value="WDC WD5003ABYX-0" number="1" />
        </blockblock>
</mb>

I am trying to find stanzas based on the value of the attributes model from the mb node and the value attribute from the second element in the first child of the mb node. So, in the stanza above, I would be trying to match against model="460" and value="H61M-P25 (MS-7680)". Having matched against that, I’d want to put rev="dba" in a list and continue searching for other stanzas with the same attributes in other mb nodes.

I haven’t gotten very far at all, I keep getting tripped on the types. I am using this to work from.

import Text.XML
import Text.XML.Cursor
import qualified Data.Text as T


getProfiles :: AdviseConf -> IO () -- AdviseResult
getProfiles  (AdviseConf model mb) = do
   doc <- Text.XML.readFile def xmlFile
   let cursor = fromDocument doc
   _ <- Prelude.writeFile "test.txt" $
        show                         $
        T.concat                     $
        cursor                       $//
        element "mb"                 >=>
        attributeIs "model" "460"    >=>
        element "dmiattr"            >=>
        attributeIs "value" "H61M-P25 (MS-7680)" 
        &// content  

I know the final function content is wrong, but I dont know which would be right. I’m trying to capture all the rev attributes from the nodes that match.

So, when I play with the above, I either end up with an empty list, junk characters, or a type error. Any help would be appreciated.

Answer 1

1. I think you’re looking for the attribute function.
2. By using >=> element "dmiattr" you’re saying “the current element’s name is dmiattr‘. I think you might mean &/ element "dmiattr". But since you want the @rev attribute of the parent, you probably need to use the check function instead.