The Developer's Console is a small OpenLaszlo application for selecting things like the target runtime, the deployment mode (proxied or SOLO) and whether the debugger is included. When you first compile an OpenLaszlo application (as explained below), by default it is returned with the Developer's Console appearing at the bottom of the application.

Depending on whether your compile to SWF (the default) or DHTML, a slightly different version of the Developer's Console is returned. The illustrations below call out features of both versions.

To run lzc you must do so from a current directory that matches the value of LPS_HOME, and LPS_HOME must be set to the correct value for the build.

Say the application to be compiled is

$LPS_HOME/laszlo-explorer/basics/mediatst.lzx

To compile it correctly you would set the current directory first:

cd $LPS_HOME;

and then compile using

lzc --script --runtime=dhtml laszlo-explorer/basics/mediatst.lzx;

Let's say the file $LPS_HOME/laszlo-explorer/basics/mediatst.lzx wants to reference the file $LPS_HOME/laszlo-explorer/basics/assets/background.jpg. It might contain the following reference.

<canvas>
  <view resource="assets/background.jpg"/>
</canvas>

Running LZC from other than LPS_HOME will result in a file not found error.

Here are the options available for compilation:

Options:

Output options:

Logging options:

You can define compile-time constants to `lzc` by using `-D_name_=_value_`, where _value_ should be either `true` or `false`. By convention, we use `$` as the first character of _name_, but nothing enforces that.

The compiler will compile only the chosen branch of an if statement when the condition expression is a compile-time constant (i.e., just the constant name, no other computation). For example:

  if ($slow) {
    ... slow way ...
  } else {
    ... fast way ...
  }

You can define compile-time constants to `lzc` by using `-D_name_=_value_`, where _value_ should be either `true` or `false`. By convention, we use `$` as the first character of _name_, but nothing enforces that. The compiler will compile only the chosen branch of an if statement when the condition expression is a compile-time constant (i.e., just the constant name, no other computation).

For example:

  if ($slow) {     ... slow way ...   } else {     ... fast way ...   } Can be made to run fast by `lzc -Dslow=false`

As part of the architectural overhaul, we have created a new version of the client runtime (LFC plus kernel). To invoke an application compiled for DHMTML, use the ?lzr=dhtml query.

The ?lzr parameter selects the runtime. Your choices are swf7, swf8, dhtml. The default is specified in lps/config/lps.properties as compiler.runtime.default. The default runtime selector is swf7.

The ?lzt parameter is the 'request type', in general what kind of 'wrapper' page will be generated around your application. Your choices are: app_console or html. app_console is the developer console, html is your app in an html page. The latter can be used as a model for embedding your app in a custom page, or you can simply embed using an iframe:

<iframe src=".../app.lzx?lzt=html"></iframe>

The default for ?lzt is specified in lps/config/lps.properties as defaultRequestType. The default value is app_console.

Mnemonics:

So, for example, to view an LZX application in DHTML within a browser, download it from a live server with an url parameter requesting the DHTML runtime lzt=html: http://myserver/mylaszloapp.lzx?lzr=dhtml. To request the SWF runtime, use http://myserver/mylaszloapp.lzx?lzr=swf.

To specify that the application run in the Developer's Console, use the lzt flag: lzt=app_console loads the application with the Developer's Console. lzr=swf7 and lzr=swf8 loads the application compiled for the SWF7 or SWF8 runtime, with the Developer's Console. Several lzr values have been added for future use, but are not currently supported: swf9, j2me, svg

You can enclose blocks of code within <switch> elements that are associated with a specific runtime. The <switch> is a compiler directive that instructs the compiler to compile or omit blocks according to the target runtime to which the application is being compiled. Within a <switch> block, use the <when> to specify the runtime.

Example 48.1. switch tag for condtional compilation

<canvas height="20">
  <switch>
    <when runtime="dhtml">
       <text>This program has been compiled for DHTML</text>
    </when>
    <otherwise>
      <text>This program has been compiled for SWF</text> 
    </otherwise>
  </switch>
</canvas>

The <font> and <face> tags are also compiler directives. Unlike most other LZX tags, they do not correspond to a class; rather, they tell the compiler which fonts and typefaces are to be bound to objects.