Need guidance to implement minify functionality

[jeevatkm]

@core-team - Can you please provide help/guidance on building Minify functionality?

[xpbliss]

In the app.conf ,
Set results.compressed=true?

[jeevatkm]

Not a gzip functionality. Need HTML minify for my revel app. Planning to use https://github.com/tdewolff/minify.

Any guidance?

[pedromorgan]

Not sure if this falls within the scope of revel..

Are u suggesting processing stuff on the fly? shoulnt this kinda stuff be served statically ?

[jeevatkm]

I'm not sure about revel scope. however if revel provides HTML minify (not JS or CSS) like compress filter. It would be great :)

You're correct for JS & CSS, it should be statically served. But I'm looking for HTML only.

[jeevatkm]

I'm trying to create one, but facing Content-Length issue. Will post my code later.

[jeevatkm]

Sorted out Content-Length issue. Created Revel MinifyFilter by referring revel.CompressFilter.

Now MinifyFilter is working fine. Can core team have a look and comment on it? if I'm missing something!

import (
    "io"
    "net/http"
    "regexp"

    "github.com/revel/revel"

    "github.com/tdewolff/minify"
    "github.com/tdewolff/minify/css"
    "github.com/tdewolff/minify/html"
    "github.com/tdewolff/minify/js"
)

var (
    m            *minify.M
    htmlMimeType *regexp.Regexp
)

type MinifyWriter struct {
    http.ResponseWriter
    minifyWriter   io.WriteCloser
    shouldMinify   bool
    headersWritten bool
    closeNotify    chan bool
    parentNotify   <-chan bool
    closed         bool
}

func Minify(c *revel.Controller, fc []revel.Filter) {
    fc[0](c, fc[1:])

    if revel.Config.BoolDefault("results.minify", false) {
        if c.Response.Status != http.StatusNoContent && c.Response.Status != http.StatusNotModified {
            mw := m.Writer("text/html", c.Response.Out)
            writer := MinifyWriter{c.Response.Out, mw, false, false, make(chan bool, 1), nil, false}

            w, ok := c.Response.Out.(http.CloseNotifier)
            if ok {
                writer.parentNotify = w.CloseNotify()
            }

            c.Response.Out = &writer
        } else {
            revel.TRACE.Printf("Minify disabled for response status (%d)", c.Response.Status)
        }
    }
}

func (c MinifyWriter) CloseNotify() <-chan bool {
    if c.parentNotify != nil {
        return c.parentNotify
    }
    return c.closeNotify
}

func (c *MinifyWriter) WriteHeader(status int) {
    c.headersWritten = true
    c.prepareHeader()
    c.ResponseWriter.WriteHeader(status)
}

func (c *MinifyWriter) prepareHeader() {
    // minify is only applied to HTML content
    if htmlMimeType.MatchString(c.Header().Get("Content-Type")) {
        c.shouldMinify = true
        c.Header().Del("Content-Length")
    }
}

func (c *MinifyWriter) Close() error {
    if c.shouldMinify {
        c.minifyWriter.Close()
    }

    if w, ok := c.ResponseWriter.(io.Closer); ok {
        w.Close()
    }

    // Non-blocking write to the closenotifier, if we for some reason should
    // get called multiple times
    select {
    case c.closeNotify <- true:
    default:
    }
    c.closed = true
    return nil
}

func (c *MinifyWriter) Write(b []byte) (int, error) {
    // Abort if parent has been closed
    if c.parentNotify != nil {
        select {
        case <-c.parentNotify:
            return 0, io.ErrClosedPipe
        default:
        }
    }

    // Abort if we ourselves have been closed
    if c.closed {
        return 0, io.ErrClosedPipe
    }

    if !c.headersWritten {
        c.prepareHeader()
        c.headersWritten = true
    }

    if c.shouldMinify {
        return c.minifyWriter.Write(b)
    } else {
        return c.ResponseWriter.Write(b)
    }
}

func init() {
    m = minify.New()

    m.AddFunc("text/css", css.Minify)
    m.AddFunc("text/html", html.Minify)
    m.AddFunc("text/javascript", js.Minify)

    htmlMimeType = regexp.MustCompile("[text|appliation]/html")
}

[jeevatkm]

It minify's HTML, inline CSS and inline JS in the HTML content.

[pedromorgan]

Ok so I get the drift.. its packing siles and js minify and gzip and compress...

The only "realm" that revel could minify in, in in the compilation of the template,, and not its variables..

However it is interesting to consider dynamic css and build stuff as part of packaging is exiting idea..

This also goes along with the "embedded data", and having a dev enviroment reading siles, and an executable with all within.. ;-)))

In go 1.6 there the {{block}} and the {{foo -}} strip me naked {{-foo}} from other temaplaing languages..

The templating and stuff is also kinda in limbo as

• smarty (confess as developer)
• django/jinga2
• golang is a pain in ass.. Am in with pongo2 with there was jinga2

[pedromorgan]

If we gonna implemeny minify etc.. then please come up with some more detail, code an even an RFC.. for now I am closing this issue. .and apologies...