Velocity | META Tags

The OnKey and OnKey0x META tags describe an action that will occur if a particular key is pressed. The key values evaluated are the same key values used by the Velocity Console. The OnKey0x format requires a unicode value and the OnKey format requires a decimal format. The key value is case sensitive.

For example:

OnKey50 and OnKey0x32 respond when the user presses 2.

OnKey65 and OnKey97 respond to both the upper and lowercase A.

The OnAllKeys tag will perform the specified action each time any key is pressed. The action type can include one argument, which is the string representing the decimal value of the key.

OnStartup, OnLoaded

The OnStartup or OnLoaded META tags allow you to specify actions that will be taken when the web page is first loaded. OnLoaded will not be called until the page has completely loaded. There are situations where OnStartup will be called before the page is completely loaded, so images, stylesheets or JavaScript files may not be available. So, for example, if OnStartup is calling a JavaScript function referenced by the web page, the call may fail. In that case, use OnLoaded to make sure that the .js file functions are available.

An example of this tag in use is provided below.

<html> <head> <Title>META Tag Onloaded Example</Title> <META http-equiv="OnLoaded" content="Javascript:helloWorld();"> <script> function helloWorld() { alert("Hello world!"); } </script> </head> <body> <h1>Onloaded Example</h1> <p>This is a sample test page.</p> </body> </html>

In this example, the function helloWorld() is called to display an alert on the device when the screen is fully loaded.

Scanner Tags

This section includes tags that enable or disable the scanner or specific symbologies.

If the action name is Scanner and the action type is Enable , the scanner will be enabled when the page is first loaded. If the action type is Disable , the scanner will be disabled when the page is first loaded.

The additional scanner action types supported by the Velocity Client include:

•ScannerNavigate

•ScannerProcessed

•Symbology

Enable and disable different scanner symbologies by using the symbology as the action name, and Enabled or Disabled as the action type. The symbologies supported by the Velocity Browser are:

AUSTRALIA_POSTAL	CUECODE	PLANET
AZTEC	D2OF1ATA	PLESSY
AZTECMESA	D2OF5	POSICODE
BOOKLAND	DATAMATRIX	POSTNET
BRITISH_POSTAL	DUTCH_POSTAL	QRCODE
CANADA_POSTAL	EAN8	RSS14
CHINA_POSTAL	EAN13	RSSEXPANDED
CODABAR	I2OF5	RSSLIMITED
CODABLOCK	JAPAN_POSTAL	SIGNATURE
CODE11	KOREA_POSTAL	TELEPEN
CODE16K	MACROPDF	TLC39
CODE32	MACROMICROPDF	TRIOPTIC39
CODE39	MAXICODE	UCC128
CODE49	MATRIX2OF5	UPCA
CODE93	MICROPDF	UPCE
CODE128	MSI	UPCE0
COMPOSITE	OCR	UPCE1
COUPONCODE	PDF417	WEBCODE

In addition to the listed symbologies, the value ALL_DECODERS can be used to enable or disable all the symbologies.

For example, to enable only UPCA use the META tags in this order:

<meta http-equiv="ALL_DECODERS" content="Disabled">

<meta http-equiv="UPCA" content="Enabled">

Scripts

You can execute scripts from web pages using the wls tag, followed by the script name or API, with or without parameters.

Use of WLS scripts requires modifying the host. However, you can bypass this through use of injection APIs for HTML, CSS, and JavaScript. These allow you to manually insert new lines of code into your existing host without touching your web pages, as shown in the video below.

Watch a related video

•Executing from the meta tag: This example launches a script called WebAuto when the web page first loads.

<title>TE70 Test1 - Launch Telnet Scripts</title>
<meta http-equiv="OnStartup" content="wls:WebAuto">

•Executing from an href: This example launches a script called WebClick when a user clicks the hyperlink "here" on the web page.

<p>
Click <a href="wls:WebClick">here</a> to launch the "WebClick" script.
</p>

•Executing within JavaScript without parameters included: The variable request is set to call the Wavelink script without specifying any parameters.

var request = "wls:dnwebdemo";

•Executing a script within JavaScript with parameters included: The script request also contains specific parameter values to input. Should you decide to include these, all parameters associated with a script must be specified here in the order they're defined for that script.

wls:setTimeout(1000,'timeout.wav',"exit","1");

•Executing with an API: This works almost exactly like calling a Wavelink script with parameters above. Instead, replace the script name with the API and enter the parameters associated.

<p>
Click <a href="wls:Device.beep(200,500,50)">here</a> to launch the "Device.beep" API.
</p>