ODAX Preexisting JavaScript Object

The ODAX Preexisting JavaScript Object contains read methods to provide offline data access. ODAX uses either a CSV or XML file on the device to provide rudimentary offline capabilities and should only be used to provide backward compatibility with legacy applications. RhoElements supports Application cache and Web SQL implementations which should be used in preference to ODAX in new applications. If you have configured ‘PreloadLegacyODAX’ to be ‘1’ the JavaScript object ‘odax’ will be inserted automatically into your page’s DOM by RhoElements. The result set is stored internally in the ‘odax’ object and is created and manipulated using the exposed methods below

• Syntax
• Methods
• Remarks
• Requirements
• HTML/JavaScript Examples

Syntax

Methods

Remarks

Good Practise

It’s good practice to check if the file exists before copying it. To do this use FileExists() method. This will support any file extension and will work as per normal file copy command. If file already exists with the same name in the destination folder/path it would be overwritten.

First Row

The delimiter and firstrow are a Select. If firstrow is set to true when creating a table with INSERT, then the field names are written to the first row as column names.

Query needed after Execute

The current result set becomes invalid after any Execute (INSERT, UPDATE, DELETE) and arbitrary values will be returned by MoveFirst etc. A new SELECT query must be performed to get valid results.

Backwards Compatibility

The ODAX Preexisting JavaScript Object provides backwards compatibility with code written for PocketBrowser and also supports the syntax below. Because RhoElements inserts the object ‘odax’ on the page automatically when ‘PreloadLegacyODAX’ is configured to be ‘1’ you can not create your own objects by this name, see below:

<script>
  //  Old PocketBrowser syntax supported by ODAX
  var myObj = new ActiveXObject("CeODAX.ODAX"); 
  
  //  Note: var odax = new ... will fail because the object already exists on the page.
  myObj.Delete('\\windows\\crazy_frog.wav');
</script>

Requirements

HTML/JavaScript Examples

The Following example shows usage of the odax object to manipulate files on the device:

<script>
   //  Copy a file
   var srcFileName = '\\application\\test.xml';
   var destFileName = '\\windows\\test.xml';
   var status1 = odax.Copy(srcFileName, destFileName);

   //  Move a file
   var status2 = odax.Move(srcFileName, destFileName);

   //  Check if a file exists
   if( true == odax.FileExists(destFileName))
   {
      alert("File: "+ destFileName + " Exists!");
   }

   //  Delete a file
   var status3 = odax.Delete(destFileName);

</script>

The following example inserts records to a XML file:

<script>
   var FieldValue1 = 'Red';
   var FieldValue2 =  Green';
   var FieldValue3 = 'Blue';

   var QueryString = 'INSERT INTO \'\\application\\test.xml\' (field1,field2,field3) VALUES (';
   QueryString += '\''+FieldValue1+'\',';
   QueryString += '\''+FieldValue2+'\',';
   QueryString += '\''+FieldValue3+'\');';
   var count = odax.Execute(QueryString,0,',',false);
</script>

The following example inserts records to a CSV file:

<script>
   var QueryString = 'INSERT INTO \'\\application\\test.csv\' (field1,field2,field3) VALUES (';
   QueryString += '\''+FieldValue1+'\',';
   QueryString += '\''+FieldValue2+'\',';
   QueryString += '\''+FieldValue3+'\');';
   var count = odax.Execute(QueryString,1,',',true);
</script>

The following example updates records in a XML file

<script>
   var fieldValue = 'Orange';
   var conditionField = 'Red';

   var QueryString = 'UPDATE \'\\application\\test.xml\' SET field1=';
   QueryString += '\''+ fieldValue +'\'';
   QueryString += ' WHERE field1=\'';
   QueryString += conditionField +"\';"
   var count = odax.Execute(QueryString,0,',',false);
</script>

The following example deletes records in a XML file

<script>
   var conditionField = 'Red';

   var QueryString = 'DELETE FROM \'\\application\\test.xml\' WHERE field1=';
   QueryString += '\''+ conditionField +'\';';
   var count = odax.Execute(QueryString,0,',',false);
</script>

The following example clears the resultset after a query is executed:

<script>
   var count = odax.Select('SELECT * FROM \'\\application\\test.xml\';', ',', false);
   odax.Clear();
</script>

The following JavaScript gets the column ‘field1’ from the resultset:

<script>
   var count = odax.Select('SELECT * FROM \'\\application\\test.xml\';', ',', false);
   var colval = odax.Get("field1");
</script>

The following JavaScript moves the row pointer to the first record of the resultset:

<script>
   var count = odax.Select('SELECT * FROM \'\\application\\test.xml\';', ',', false);
   var result = odax.MoveFirst();
</script>

The following JavaScript moves the row pointer to the next record in the resultset:

<script>
   var count = odax.Select('SELECT * FROM \'\\application\\test.xml\';', ',', false);
   var result = odax.movenext();
</script>

The following JavaScript moves the row pointer to the previous record in the resultset:

<script>
   var count = odax.Select('SELECT * FROM \'\\application\\test.xml\';', ',', false);
   var result = odax.moveprev();
</script>

The following JavaScript moves the row pointer to the last record of the resultset

<script>
   var count = odax.Select('SELECT * FROM \'\\application\\test.xml\';', ',', false);
   var result = odax.movelast();
</script>

The following JavaScript selects all records from a XML file:

<script>
   var count = odax.Select('SELECT * FROM \'\\application\\test.xml\';', ',', false);
</script>