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XML query examples
The scripts below illustrate XML queries. To run the examples, paste the segments into the Actions section of your script. Make sure to enable the Extended Log in the Runtime Settings with Parameter substitution, so that you can view the values of the result parameter in the Execution log. For details, see the VuGen Online Help Center.
Example: Get values
This example demonstrates queries using lr_xml_get_values.
The function lr_xml_get_values executes queries on the string xml_input. The results of each query are stored in the parameter Result.
#include "as_web.h"
/* The XML Data */
char *xml_input=
"<acme_org>"
" <accounts_dept>"
"<employee>"
" <name>Kevin Sharp</name>"
"<cubicle>227</cubicle>"
"<extension>2145</extension>"
"</employee>"
"</accounts_dept>"
"<engineering_dept>"
"<employee>"
"<name>John Smith</name>"
"<cubicle>372</cubicle>"
"<extension>2970</extension>"
"</employee>"
"<employee level=\"manager\">"
"<name>Sue Jones</name>"
"<extension>2375</extension>"
"</employee>"
"</engineering_dept>"
"</acme_org>";
Action() {
int query_number = 1;
// Save data as parameter
lr_save_string(xml_input, "XML_Input_Param");
/* Query 1: Find the first employee's name
(To find the names of all employees
see Multiple Query Matching) */
lr_xml_get_values("XML={XML_Input_Param}",
"ValueParam=Result",
"Query=/acme_org/*/employee/name",
LAST );
/* Query 2: Find the first extension number one
or more levels deep */
lr_xml_get_values("XML={XML_Input_Param}",
"ValueParam=Result",
"Query=//extension",
LAST );
/* Query 3: Find the name of the manager
of the engineering department. */
lr_xml_get_values("XML={XML_Input_Param}",
"ValueParam=Result",
"Query=/acme_org/engineering_dept/employee[@level=\"manager\"]/name",
LAST );
/* Query 4: Find the name of an employee
whose extension number is 2970 */
lr_xml_get_values("XML={XML_Input_Param}",
"ValueParam=Result",
"Query=/acme_org/*/employee[extension=\"2970\"]/name",
LAST );
return 0;
}
Example: Output from Execution Log Window:
Action.c(33): Saving Parameter "Result = Kevin Sharp"
Action.c(33): "lr_xml_get_values" was successful, 1 match processed
Action.c(37): Saving Parameter "Result = 2145"
Action.c(37): "lr_xml_get_values" was successful, 1 match processed
Action.c(41): Saving Parameter "Result = Sue Jones"
Action.c(41): "lr_xml_get_values" was successful, 1 match processed
Action.c(46): Saving Parameter "Result = John Smith"
Action.c(46): "lr_xml_get_values" was successful, 1 match processed
Examples: common actions
The following examples demonstrate a variety of XML functions and expressions. To run the examples, paste their content into the Action section of a Web Services Vuser script.
Store XML segment in pxml buffer
#include "as_web.h"
char* pxml =
"<abc>"
"<employee>"
"<name>Thomas Bertram</name>"
"<cubicle sign=\"Amateur Theater Club\">"
"227</cubicle>"
"<extension>2145</extension>"
"<manager>"
"<name>Lady Maria Bertram</name>"
"<extension>2375</extension>"
"<extension>0</extension>"
"</manager>"
"</employee>"
"<employee>"
"<name>Henry Crawford</name>"
"<cubicle sign=\"Fidelity\">227</cubicle>"
"<extension>2794</extension>"
"<manager>"
"<name>Admiral Crawford</name>"
"<extension>2309</extension>"
"<extension>0</extension>"
"</manager>"
"</employee>"
"<employee>"
"<name>Fanny Price</name>"
"<cubicle sign=\"Marry my cousin\""
" test=\"test attrib value\">666</cubicle>"
"<manager>"
"<name>Edmund Bertram</name>"
"<extension>2391</extension>"
"<extension>0</extension>"
"</manager>"
"</employee>"
"</abc>";
Action()
{
int find_cnt;
// save XML string into parameter
lr_save_string( pxml, "ParamXml" );
/*
Delete element by a specific attribute value
*/
lr_xml_delete("Xml={ParamXml}",
"Query=//cubicle[@sign=\"Fidelity\"]",
"ResultParam=Result",
LAST
);
//Action.c(59): "lr_xml_delete" was successful, 1 match processed
/* Delete by specific Sign value:
***********
Input:
...
"<employee>"
"<name>Henry Crawford</name>"
"<cubicle sign=\"Fidelity\">227</cubicle>"
"<extension>2794</extension>"
...
"</employee>"
Output:
Note that Henry's cubicle has been deleted
...
<employee><name>Henry Crawford</name> <extension>2794</extension>
...
</employee> *****
*/
/*
Delete the first "sign" attribute
*/
lr_xml_delete("Xml={ParamXml}",
"Query=//cubicle/@sign",
"ResultParam=Result",
"SelectAll=yes",
LAST
);
//Action.c(75): "lr_xml_delete" was successful, 3 matches processed
/* Delete First Sign :
***********
Input:
"<abc>"
"<employee>"
"<name>Thomas Bertram</name>"
"<cubicle sign=\"Amateur Theater Club\">"
"227</cubicle>"
"<extension>2145</extension>"
Output:
Note that Sir Thomas's cubicle no longer has a sign.
<abc> <employee> <name>Thomas Bertram</name> <cubicle>227</cubicle> <extension>2145</extension>
...
*****
Replace all "sign" attributes with an XML fragment
lr_xml_replace( "Xml={ParamXml}",
"Query=//cubicle/@sign",
"ResultParam=Result",
"XmlFragment="
"NewSign=\"Marry\" NewSign1=\"test\"",
"SelectAll=yes",
LAST
);
//Action.c(100): "lr_xml_replace" was successful, 3 matches processed
lr_message(lr_eval_string
("/* Replace sign elements:\n***********\n{Result}\n******/"));
/* Replace sign elements:
***********
<abc> <employee> <name>Thomas Bertram</name> <cubicle NewSign="Marry" NewSign1="test">227</cubicle> <extension>2145</extension> <manager> <name>Lady Maria Bertram</name> <extension>2375</extension> <extension>0</extension> </manager> </employee> <employee> <name>Henry Crawford</name> <cubicle NewSign="Marry" NewSign1="test">227</cubicle> <extension>2794</extension> <manager> <name>Admiral Crawford</name> <extension>2309</extension> <extension>0</extension> </manager> </employee> <employee> <name>Fanny Price</name> <cubicle NewSign="Marry" NewSign1="test" test="test attrib value">666</cubicle> <manager> <name>Edmund Bertram</name> <extension>2391</extension> <extension>0</extension> </manager> </employee> </abc>
*****
*/
Replace all "sign" attributes with a parameter set
lr_save_string
( "sign= \"The First New Sign\"", "NewSign_1" );
lr_save_string
( "sign= \"The Second New Sign\"", "NewSign_2" );
lr_save_string
( "sign= \"The Third New Sign\"", "NewSign_3" );
lr_xml_replace( "Xml={ParamXml}",
"Query=//cubicle/@sign",
"ResultParam=Result",
"XmlFragmentParam=NewSign",
"SelectAll=yes",
LAST
);
lr_message(lr_eval_string
("/* Replace sign attributes:\n***********\n{Result}\n*****\n*/"));
/* Replace sign attributes:
***********
<abc> <employee> <name>Thomas Bertram</name> <cubicle sign="The First New Sign">227</cubicle> <extension>2145</extension> <manager> <name>Lady Maria Bertram</name> <extension>2375</extension> <extension>0</extension> </manager> </employee> <employee> <name>Henry Crawford</name> <cubicle sign="The Second New Sign">227</cubicle> <extension>2794</extension> <manager> <name>Admiral Crawford</name> <extension>2309</extension> <extension>0</extension> </manager> </employee> <employee> <name>Fanny Price</name> <cubicle test="test attrib value" sign="The Third New Sign">666</cubicle> <manager> <name>Edmund Bertram</name> <extension>2391</extension> <extension>0</extension> </manager> </employee> </abc>
*****
*/
Insert an attribute to the root
/* "abc" is the root, so the insertion will be outside all the child elements
*/
lr_xml_insert("Xml={ParamXml}",
"Query=/abc",
"ResultParam=Result",
"Position=attribute",
"XmlFragment=typeAttr=\"good\"",
LAST
);
//Action.c(118): "lr_xml_insert" was successful, 1 match processed
lr_message(lr_eval_string
("/* Insert root attribute:\n***********\n{Result}\n*****\n*"));
/* Insert root attribute:
***********
<abc> <employee> <name>Thomas Bertram</name> <cubicle sign= ... <employee> <name>Fanny Price</name> ... </employee>typeAttr="good"</abc>
*****
*/
Insert a child in all elements using a parameter
/* Only one parameter, ParamComputer_2, is defined.
For the other undefined elements, "{ParamComputer_n}" is
inserted.
*/
lr_save_string
("<computer>ferrari</computer>",
"ParamComputer_2");
lr_xml_insert("Xml={ParamXml}",
"Query=//employee/manager",
"ResultParam=Result",
"XmlFragmentParam=ParamComputer",
"SelectAll=yes",
"Position=child",
LAST
);
//Action.c(140): "lr_xml_insert" was successful, 3 matches processed
lr_message(lr_eval_string
("/* Parameter insertion:\n***********\n{Result}\n*****\n*/"));
/* Parameter insertion:
***********
<abc> <employee> <name>Thomas Bertram</name> <cubicle sign="Amateur Theater Club">227</cubicle> <extension> 2145 </extension> <manager> <name>Lady Maria Bertram</name> <extension> 2375 </extension> <extension>0</extension>{ParamComputer_1}</manager> </employee> <employee> <name>Henry Crawford</name> <cubicle sign="Fidelity"> 227</cubicle> <extension>2794</extension> <manager> <name>Admiral Crawford</name> <extension>2309</extension> <extension>0</extension> <computer>ferrari</computer> </manager> </employee> <employee> <name>Fanny Price</name> <cubicle test="test attrib value" sign="Marry my cousin">666</cubicle> <manager> <name>Edmund Bertram</name> <extension>2391</extension> <extension>0</extension>{ParamComputer_3}</manager> </employee> </abc>
*****
*/
Get a fragment
lr_xml_extract( "Xml={ParamXml}",
"Query=//cubicle[@sign=\"Fidelity\"]",
"XMLFragmentParam=Result",
LAST
);
//Action.c(158): "lr_xml_extract" was successful, 1 match processed
lr_message(lr_eval_string
("/* Result:\n***********\n{Result}\n*****\n*"));
/* Result:
***********
<cubicle sign="Fidelity">227</cubicle>
*****
*/
Find a first occurrence
/* This is the first occurrence, so the default "SelectAll=no does not prevent the find from working */
find_cnt = lr_xml_find( "Xml={ParamXml}",
"Query=//cubicle/@sign",
"Value=Amateur Theater Club",
LAST
);
//Action.c(177): "lr_xml_find" was successful, 1 match processed
lr_message
("sign = Amateur Theater Club: Found %d matches", find_cnt);
/*
sign = Amateur Theater Club: Found 1 matches
*/
Find a partial string
/* The complete string is "Marry my cousin". lr_xml_find will not find the partial string "Marry" as a literal value
*/
find_cnt = lr_xml_find( "Xml={ParamXml}",
"Query=//cubicle/@sign",
"Value=Marry",
"SelectAll=yes",
"NotFound=Continue",
LAST
);
/*
Action.c(189): Error: no matches were found for the specified query [class:CLrXmlScriptFunc]
Action.c(189): Error: "lr_xml_find" execution failed
Action.c(189): Continuing after error in Vuser script.
*/
Find a partial string with regular expressions
/* To find a partial string, you can use regular expressions. Here we find "Marry" at the beginning of the value
*/
find_cnt = lr_xml_find( "Xml={ParamXml}",
"Query=//cubicle/@sign",
"Value=^Marry",
"SelectAll=yes",
"UseRegExp=yes",
LAST
);
//Action.c(204): "lr_xml_find" was successful, 1 match processed
lr_message
("sign = ^Marry: Found %d matches", find_cnt);
//sign = ^Marry: Found 1 matches
/* Here we find "my cousin" at the end of the
value */
find_cnt = lr_xml_find( "Xml={ParamXml}",
"Query=//cubicle/@sign",
"Value=my cousin$",
"SelectAll=yes",
"UseRegExp=yes",
LAST
);
// Action.c(215): "lr_xml_find" was successful, 1 match processed
lr_message("sign = my cousin$: Found %d matches", find_cnt);
//sign = my cousin$: Found 1 matches
/* Here we find "my" anywhere except the beginning or
end of the value */
find_cnt = lr_xml_find( "Xml={ParamXml}",
"Query=//cubicle/@sign",
"Value=.+my.+",
"SelectAll=yes",
"UseRegExp=yes",
LAST
);
lr_message("sign = .+my.+: Found %d matches", find_cnt);
//sign = .+my.+: Found 1 matches
Find a complete string that is not the first occurrence
/* lr_xml_find will find the entire string, but unless SelectAll=yes is specified, it will only find the first occurrence
*/
find_cnt = lr_xml_find( "Xml={ParamXml}",
"Query=//cubicle/@sign",
"Value=Marry my cousin",
"NotFound=Continue",
LAST
);
/*
Action.c(237): Error: no matches were found for the specified query [class:CLrXmlScriptFunc]
Action.c(237): Error: "lr_xml_find" execution failed
Action.c(237): Continuing after error in Vuser script.
*/
lr_message
("sign = Marry my cousin (SelectAll default = no): Found %d matches", find_cnt);
/*
sign = Marry my cousin (SelectAll default = no): Found 0 matches
*/
/* Try the same query with SelectAll=yes */
find_cnt = lr_xml_find( "Xml={ParamXml}",
"Query=//cubicle/@sign",
"Value=Marry my cousin",
"SelectAll=yes",
LAST
);
//Action.c(248): "lr_xml_find" was successful, 1 match processed
lr_message
("sign = Marry my cousin (SelectAll=Yes): Found %d matches", find_cnt);
/*
sign = Marry my cousin (SelectAll=Yes): Found 1 matches
*/
Specify the occurrence
/* Without specifying SelectAll=yes, lr_xml_find will still find a specified employee occurrence, [3]. Note that "Query=//cubicle[3]/@sign" will not work. "cubicle[3]" would look for the third cubicle under any employee.
*/
find_cnt = lr_xml_find( "Xml={ParamXml}",
"Query=//employee[3]/cubicle/@sign",
"Value=Marry my cousin",
LAST
);
// Action.c(287): "lr_xml_find" was successful, 1 match processed
lr_message
("Third employee, sign = Marry my cousin (SelectAll default = no): Found %d matches", find_cnt);
/*
Third employee, sign = Marry my cousin (SelectAll default = no): Found 1 matches
*/
Get attribute values
/* Value functions make no changes in the XML structure, but changes values. This example returns the first occurrence */
lr_xml_get_values( "Xml={ParamXml}",
"Query=//cubicle/@sign",
"ValueParam=ResultValue",
LAST
);
//Action.c(265): "lr_xml_get_values" was successful, 1 match processed
lr_message (lr_eval_string
("*/\n\n/* Get sign values:\n***********\n{ResultValue}\n*****\n*/\n/*"));
/* Get sign values:
***********
Amateur Theater Club
*****
*/
Set attribute values
/*
Example of common error:
This is common mistake when trying replace the value of an attribute. Note that if you ran this query:
lr_xml_set_values( "Xml={ParamXml}",
"Query=//cubicle[@sign=\"Marry my cousin\"]",
"Value=Do not marry Henry",
"ResultParam=Result",
LAST
);
It would find the element whose sign is "Marry my cousin",
which is
<employee><name>Fanny Price</name>
<cubicle sign="Marry my cousin"
test="test attrib value">666
</cubicle>
and replace the value, "666", with the phrase
"Do not marry Henry"
This would be the result:
<employee><name>Fanny Price</name>
<cubicle test="test attrib value"
sign="Marry my cousin">Do not marry Henry
</cubicle>
The intent is to replace the value of the sign attribute.
Use the format in the query below:
"Query=//cubicle[@sign=\"Marry my cousin\"]/@sign"
This means, find the sign attribute of the element whose
sign attribute value is "Marry my cousin".
The following command replaces the value of the attribute, and not of the element.
*/
lr_xml_set_values("Xml={ParamXml}",
"Query=//cubicle[@sign=\"Marry my cousin\"]/@sign",
"Value=Do not marry Henry",
"ResultParam=Result",
LAST
);
//Action.c(313): "lr_xml_set_values" was successful, 1 match processed
lr_message(lr_eval_string
("*/\n\n/* Do not marry Henry:\n***********\n{Result}\n*****\n*/\n/*"));
/* Do not marry Henry:
***********
<abc> <employee> <name>Thomas Bertram</name> <cubicle sign="Amateur Theater Club">227</cubicle> <extension>2145</extension> <manager> <name>Lady Maria Bertram</name> <extension>2375</extension> <extension>0</extension> </manager> </employee> <employee> <name>Henry Crawford</name> <cubicle sign="Fidelity">227</cubicle> <extension>2794</extension> <manager> <name>Admiral Crawford</name> <extension>2309</extension> <extension>0</extension> </manager> </employee> <employee> <name>Fanny Price</name> <cubicle test="test attrib value" sign="Do not marry Henry">666</cubicle> <manager> <name>Edmund Bertram</name> <extension>2391</extension> <extension>0</extension> </manager> </employee> </abc>
*****
*/
return 0;
}
