Using Find

There are two types of find operations allowed on any object that inherits from the class os_element_group .

Find First

Use the function find_first() to find the first instance of a key and return a pointer to the element. If no matching element is found, find_first() returns a pointer with a value of 0 (zero).

In the following example, a key named mykey is given to the text element hello . When the function find_first() is called, it iterates through the page and streams the first element with the key mykey back to the page. This results in displaying both text elements.

Example <ospace/web/ examples/find1.cpp>
#include <iostream.h>
#include <ospace/web.h>

int main()
  {
  os_page page( "Find#1 Example" );

  os_text hello( "Hello world!" );
  hello.key( "mykey" );

  page << hello << os_break();

  os_element* found = page.find_first( "mykey" );

  if ( found )
    page << *found << os_break();

  cout << page;
  return 0;
  }

Find All

Use the function find_all() to find all occurrences of a key and return a vector of os_element pointers. If no matching elements are found, find_all() returns an empty list.

In the following example a new text element, named how , is added to the Web page page in the previous example. The same key, mykey , is given to this new element. When the function find_all() is called, it iterates through the page and streams each element back to the page. This results in displaying both text elements.

Example <ospace/web/ examples/find2.cpp>
#include <iostream.h>
#include <ospace/web.h>

int main()
  {
  os_page page( "Find#2 Example" );

  os_text hello( "Hello world!" );
  hello.key( "mykey" );

  os_text how( "How are you?!" );
  how.key( "mykey" );

  page << hello << os_break()
       << how << os_break();

  vector< os_element* > found = page.find_all( "mykey" );

  vector< os_element* >::iterator it;

  for ( it = found.begin(); it != found.end(); it++ )
    page << **it << os_break();

  cout << page;
  return 0;
  }

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