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Version: 3.1.X

Element <do>

The <do> element indicates the beginning of an IsisScript task. It is the central processing unit of the script.

Usage​

  • Allowed content: <call> <cgitable> <define> <display> <do> <export> <extract> <field> <file> <flow> <hl> <label> <list> <loop> <parm> <proc> <return> <trace> <update>
  • Parent elements: <do> <function> <hl> <loop> <section> <update>

Syntax​

<do [task="TASK_NAME"]>
    </do>

The task attribute is used to indicate the type of task to be executed. The parameters for execution are indicated with the <parm> element. The <loop> element indicates the set of instructions to be executed for each task item.

Attribute task​

Options: fullinvertion import invertedload keyrange list mastersort mfnrange search update

It identifies the task to be performed.

Generic Repetition (No Task)​

The absence of the task attribute indicates a task-independent repetition. It simply loops a specific number of times defined by the parameter to.

Example

<do>
   <parm name="to">500</parm>
   <field action="define" tag="1001">Isis_Current</field>
   <field action="define" tag="1002">Isis_Total</field>
   <loop>
      <display>
         <pft>newline('<br>'),v1001,'/',v1002/</pft>
      </display>
   </loop>
</do>

Task Details​

task="fullinvertion"​

Performs the full generation of the database inverted file (IF).

  • <parm name="db">: Database name.
  • <parm name="fst">: The FST (Field Select Table) to be used.

Example

<do task="fullinvertion">
   <parm name="db"><pft>v2001</pft></parm>
   <parm name="fst"><pft>v2061</pft></parm>
   <field action="define" tag="1102">Isis_Status</field>
   <display><pft>'Full invertion: ',v2001/</pft></display>
   <loop></loop>
   <display><pft>'Finished.'/</pft></display>
   <display><pft>'Lock status = 'v1102/</pft></display>
</do>

task="import"​

Imports data from a text file, loading it as database records.

  • <parm name="file">: The input file name.
  • <parm name="type">: (Optional) File type. If not specified, ISO-2709 is assumed.

Example

<do task="import">
   <parm name="file"><pft>v2041</pft></parm>
   <parm name="type"><pft>v2042</pft></parm>
   <loop>
      <display><pft>ALL</pft></display>
   </loop>
</do>

task="invertedload"​

Loads the inverted file using a temporary database containing pre-sorted keys.

  • <parm name="db">: Target database name (whose inverted file is being loaded).
  • <parm name="keysdb">: Source database name (containing sorted keys).

Example

<do task="invertedload">
   <parm name="db">TEST</parm>
   <parm name="keysdb">TESTKEYS</parm>
   <field action="define" tag="1">Isis_Posting</field>
   <field action="define" tag="2">Isis_Key</field>
   <field action="define" tag="1102">Isis_Status</field>
   <display><pft>'Inverted load ...'/</pft></display>
   <loop></loop>
   <display><pft>'Lock status = 'v1102/</pft></display>
   <flow action="exit">
      <pft>if val(v1102) <> 0 then v1102 fi</pft>
   </flow>
   <display><pft>'Inverted load: TEST loaded.'/</pft></display>
</do>

task="keyrange"​

Accesses the database inverted file (Dictionary).

  • <parm name="db">: Database name.
  • <parm name="from">: Initial key (term).
  • <parm name="to">: Final key (term).
  • <parm name="count">: Max number of keys.
  • <parm name="reverse">: If set, access keys in reverse order.
  • <parm name="posting">: Iterates through the postings list of each key.
  • <parm name="posttag">: Iterates through postings for a specific tag.

Example

<do task="keyrange">
   <parm name="db"><pft>v2001</pft></parm>
   <parm name="from">
      <pft>v2002,if a(v2002) then v2101 fi</pft>
   </parm>
   <parm name="count"><pft>v2003,"20"n2003</pft></parm>
   <parm name="reverse"><pft>v2004</pft></parm>
   <parm name="to"><pft>v2006</pft></parm>

   <field action="define" tag="1001">Isis_Current</field>
   <field action="define" tag="1">Isis_Key</field>
   <field action="define" tag="2">Isis_Postings</field>

   <display><pft>'##) POSTINGS',c15,'KEY'/#</pft></display>

   <loop>
      <display>
         <pft>f(val(v1001),2,0),') ',v2,c15,v1/</pft>
      </display>
   </loop>
</do>

task="list"​

Accesses a list of items previously loaded with the <list> element.

  • <parm name="from">: Starting item index.
  • <parm name="to">: Last item index.
  • <parm name="count">: Number of items to process.
  • <parm name="reverse">: Process list in reverse order.
  • <parm name="sort">: (Optional) Sorts the list before processing.

Example

<list action="load" type="sort"><pft>'1'/,'2'/,'3'/</pft></list>
<list action="load" type="sort"><pft>'9'/,'8'/,</pft></list>
<list action="load" type="sort"><pft>'F'/,'Z'/,'A'/</pft></list>

<do task="list">
   <field action="define" tag="1001">Isis_Current</field>
   <field action="define" tag="1002">Isis_Items</field>
   <field action="define" tag="1">Isis_Item</field>
   <loop>
       <display>
          <pft>v1001,'/',v1002,c10,v1/</pft>
       </display>
   </loop>
</do>

task="mastersort"​

Sorts the records of the master file physically (or generates a sorted copy).

  • <parm name="db">: Database name.
  • <parm name="key">: The PFT expression defining the sort key.
  • <parm name="keylength">: Maximum length of the sort key.

Example

<do task="mastersort">
   <parm name="db">CDS</parm>
   <parm name="key"><pft>v24</pft></parm>
   <parm name="keylength">100</parm>
   <field action="define" tag="1102">Isis_Status</field>

   <display><pft>'Key sort ...'/</pft></display>
   <loop></loop>
   <display><pft>'Lock status = 'v1102/</pft></display>
   <display><pft>'Key sort: CDS sorted.'/</pft></display>
</do>

task="mfnrange"​

Accesses a range of database records sequentially by MFN.

  • <parm name="db">: Database name.
  • <parm name="from">: Initial MFN.
  • <parm name="to">: Final MFN.
  • <parm name="count">: Max number of records.
  • <parm name="reverse">: Process in reverse MFN order.

Example

<do task="mfnrange">
   <parm name="db">CDS</parm>
   <parm name="from">25</parm>
   <parm name="count">10</parm>
   <loop>
      <display><pft>ALL</pft></display>
   </loop>
</do>

task="search"​

Retrieves records using a boolean search expression.

  • <parm name="db">: Database name.
  • <parm name="expression">: Search query (e.g., water * soil).
  • <parm name="from">: Start from the Nth result.
  • <parm name="count">: Limit results count.
  • <parm name="reverse">: Process results in reverse order (highest MFN first).

Example

<do task="search">
   <parm name="db">CDS</parm>
   <parm name="expression">plants * water</parm>
   <loop>
      <display><pft>mfn/</pft></display>
   </loop>
</do>

task="update"​

Updates existing records or adds new ones.

  • <parm name="db">: Database name.
  • <parm name="mfn">: Specific MFN to update, or New to create one.
  • <parm name="lockid">: User/Session ID for record locking.
  • <parm name="expire">: Lock expiration time in seconds.

Example

<do task="update">
   <parm name="db">CDS</parm>
   <parm name="mfn">New</parm>
   <field action="define" tag="1102">Isis_Status</field>

   <update>
      <field action="replace" tag="20">
         <pft>date</pft>
      </field>
      <write>Unlock</write>
      <display><pft>ALL</pft></display>
   </update>
</do>