Torque
  1. Torque
  2. TORQUE-71

custom velocity renderer to have nicely trimmed generated code

    Details

    • Type: Improvement Improvement
    • Status: Closed
    • Priority: Minor Minor
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 3.3-RC3
    • Component/s: Generator
    • Labels:
      None

      Description

      The current Torque templates have spaces and tabs in front of Velocity commands (#foreach, #set, #end,...). The Velocity renderer puts this spaces and tabs into the generated code - that is the reason why the code in generated Base* class files looks sometimes a little bit ugly. If we remove the leading spaces in front of Velocity commands we can avoid this problem.

      My solution is to override the rendering method in org.apache.velocity.texen.ant.TexenTask that Torque uses to render the templates and replace the template loader with our own. Therefor we can remove the leading spaces.

      /**

      • This method filters the template and replaces some
      • unwanted characters. For example it removes leading
      • spaces in front of velocity commands and replaces
      • tabs with spaces to prevent bounces in different
      • code editors with different tab-width-setting.
        */
        protected byte[] filter(String template, String encoding) throws Exception {
        StringReader stringReader = new StringReader(template);
        LineNumberReader lineNumberReader = new LineNumberReader(stringReader);
        String line = null;
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        PrintStream ps = new PrintStream(baos,true,encoding);

      while ((line = lineNumberReader.readLine()) != null)

      { // remove leading spaces in front of velocity commands and comments line = line.replaceAll("^\\s*#", "#"); // replace tabs with spaces to prevent bounces in editors line = line.replaceAll("\t"," "); ps.println(line); }

      ps.flush();
      ps.close();

      return baos.toByteArray();
      }

      The only problem is, that this would generate an error if you use empty statements in #if or #foreach commands, for example
      #if (something)
      #end

      This would create an error in velocity's render engine if you remove the leading spaces - because empty statements are not allowed in Velocity. But this can be avoided by add a single new line:

      #if (something)

      #end

      A patch for the current generator comes in the next days.

      1. patch.txt
        30 kB
        Thoralf Rickert
      2. TorqueDataModelTask.java
        24 kB
        Thomas Fox

        Activity

        Hide
        Thoralf Rickert added a comment -

        Okay, here is a first patch. I didn't test it, because I don't have a suitable test environment. What I did was to change the TorqueDataModelTask class. I've copied! the execute method from velocity-TexenTask class. Then I've changed the TemplateLoader for FileResourceLoader and ClasspathResourceLoader with my own loaders (which extends File- and ClasspathResourceLoader) and call the filter method (it uses streams now).

        I'm not sure if the code compiles and runs because the Task uses two different StringUtils classes and I'm not sure, if I checked everything. AND I'm not sure if the template loader has any problems with the template syntax (see discussion in July). Please report any problems - I'll try to find the problem.

        We use this filter here since last year in our own TemplateLoader which get's the templates from a database - so I'm sure that it works in principle but there could be one or more templates that has to be changed.

        Show
        Thoralf Rickert added a comment - Okay, here is a first patch. I didn't test it, because I don't have a suitable test environment. What I did was to change the TorqueDataModelTask class. I've copied! the execute method from velocity-TexenTask class. Then I've changed the TemplateLoader for FileResourceLoader and ClasspathResourceLoader with my own loaders (which extends File- and ClasspathResourceLoader) and call the filter method (it uses streams now). I'm not sure if the code compiles and runs because the Task uses two different StringUtils classes and I'm not sure, if I checked everything. AND I'm not sure if the template loader has any problems with the template syntax (see discussion in July). Please report any problems - I'll try to find the problem. We use this filter here since last year in our own TemplateLoader which get's the templates from a database - so I'm sure that it works in principle but there could be one or more templates that has to be changed.
        Hide
        Thomas Fox added a comment -

        The provided patch did not work, it threw an InstantiationException on a changed loader. Here is a new patch. Also, the handling of encoding in the filter was improved in the patch

        Show
        Thomas Fox added a comment - The provided patch did not work, it threw an InstantiationException on a changed loader. Here is a new patch. Also, the handling of encoding in the filter was improved in the patch
        Hide
        Thomas Fox added a comment -

        The patch still needs to be javadoced

        Show
        Thomas Fox added a comment - The patch still needs to be javadoced
        Hide
        Thomas Fox added a comment -

        Patch applied, thanks

        Show
        Thomas Fox added a comment - Patch applied, thanks

          People

          • Assignee:
            Unassigned
            Reporter:
            Thoralf Rickert
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            Dates

            • Created:
              Updated:
              Resolved:

              Development