core-rewriter 2.2.232

node:

Text

THE

rewrite_js()

FUNCTION

mixer

core-rewriter 2.2.232

category

Modify

{

Overview

Rewrites javascript to the correct domain.

The rewrite js function ensures that all javascript points to the correct domain - rewriting anything from a regular desktop link to a modified link. For example, the domain example.com will be rewritten as m.example.com on a mobile site in the javascript.

This function has no arguments

Example

rewrite_js()

View Source

@func Text.rewrite_js() {
replace(/((?:(?:(?:[a-zA-Z0-9][a-zA-Z0-9\-]*)(?:\.[\.a-zA-Z0-9\-]*))|localhost)(?:\:[0-9]+)?)/i) {
    $host_hh = $1

    $host_hh {
      rewrite_to_proxy($secure, $__catch_all__)
    }
    set($host_hh)
  }
}

node:

Text

THE

rewrite_link()

FUNCTION

mixer

core-rewriter 2.2.232

category

Modify

{

Overview

Rewrites links to point to the correct domain.

The rewrite link function takes links on the regular site and rewrites them to modified links. On a mobile site, you do not want the links to point to the desktop site. This function fixes that. For most projects, link rewriting is done automatically via the "rewrite_links()" function found in html.ts. In the example below, we rewrite the links with the class "internal" so that they remain on the Moovweb site.

This function has no arguments

Example

$(".//a[@class='internal']") {
  attribute("href") {
    value() {
      rewrite_link()
    }
  }
}
rewrite_link()

View Source

@func Text.rewrite_link() {
match_not(this(), /^mailto:/) {
    replace(/((?:(?:(?:http(?:s?)):)?(?:\/\/)?(?:(?:[a-zA-Z0-9][a-zA-Z0-9\-]*)(?:\.[\.a-zA-Z0-9\-]*)|localhost))(?:\:[0-9]+)?)/i) {
      $host_hh = $1

      $host_hh {
        rewrite_to_proxy($secure, $__catch_all__)
      }
      set($host_hh)
    }
  }
}

node:

XMLNode

THE

rewrite_links()

FUNCTION

mixer

core-rewriter 2.2.232

category

Modify

{

Overview

Rewrites all the links in the pages so that the proxy isn't escaped.

The rewrite_links() function will rewrite all links on the page so that the host of the resultant link is still the project's host, not the source host.

This function has no arguments

Example

$("/html") {
  rewrite_links()
}

View Source

@func XMLNode.rewrite_links() {
$("./body") {
    # Rewrite links
    $(".//a") {
      attribute("href") {
        value() {
          rewrite_link()
        }
      }
    }
    $("/html/head/base[@href]") {
      # save the initial value of base into an attribute before rewriting for (possible) use later
      %initial_value = ""
      attribute("href") {
        %attr_val = value()
        %initial_value {
          set(%attr_val)
        }
        value() {
          rewrite_link()
        }
      }
      attribute("initial-value", %initial_value)
    }
    # Rewrite form actions
    $(".//form") {
      attribute("action") {
        value() {
          rewrite_link()
        }
      }
    }
  }
  rewrite_meta_refresh()
}

node:

XMLNode

THE

rewrite_meta_refresh()

FUNCTION

mixer

core-rewriter 2.2.232

category

Modify

{

Overview

Rewrites the meta refreshes on the page.

The rewrite_meta_refresh will rewrite the meta refreshes on the page so that the host of the redirection url is still the project's host, not the source host.

Argument

Type

Name

%selector

Example

rewrite_meta_refresh() # in any XMLNode scope

View Source

@func XMLNode.rewrite_meta_refresh() {
$("/html/head/meta") {
    %refresh_tag = fetch("@http-equiv")
    %refresh_tag {
      replace(/\s\s+/, " ")
      replace(/^\s+|\s+$/, "")
    }
    match(%refresh_tag) {
      with(/refresh/i) {
        attribute("content") {
          value() {
            replace(/(.*?;)(URL=)?(.*)/i) {
              %timeout = $1
              %prefix = $2
              %url = $3
              %url {
                rewrite_link()
              }
              set(%timeout + %prefix + %url)
            }
          }
        }
      }
    }
  }
}

node:

XMLNode

THE

unproxy(Text %attr_name)

FUNCTION

mixer

core-rewriter 2.2.232

category

Modify

{

Overview

Unproxies the specified attribute of the scoped XMLNode.

The unproxy function will turn the specified attributes value into an absolute path if needed, resulting in the asset not being proxied. It takes into account the nuanced interactions of the base tag, meaning you won't have to worry about it. # The example below will unproxy the src attribute of the first node with one.

Argument

Type

Name

%attr_name

Example

$("(//*[@src])[1]") {
  unproxy("src")
}

View Source

@func XMLNode.unproxy(Text %attr_name) {
# simple overview: the base tag is the starting point for realtive URLs in the document
  # for more info on what exactly the base tag is and what it does, 
  # visit http://www.w3schools.com/tags/tag_base.asp

  # outline of how to deal with the base tag (lot of if this, do that...):
  #
  #   (1) if the link we want to unproxy is absolute, it is already unproxied (assuming you don't rewrite the absolute path to go through the proxy)
  #   (2) save the path for the current request and the path on the base tag for later use (space and slash trimming where appropriate)
  #   (3) if the base tag is empty, don't need to worry about the weirdness of the base tag (it doesn't exist), use standard relative link behavior
  #   (4)     if the link is host-relative, prepend the source host
  #   (5)     otherwise it's path-relative, prepend the source host and request's path
  #   (6) if the base tag is not rewritten (and not empty since we should've taken care of that case)
  #   (7)     if the base href has host/scheme, do nothing, browser will generate correct absolute path automatically
  #   (8)     if the base href is host-relative
  #   (9)         if the link is host-relative, just prepend the source host
  #  (10)         otherwise it's path-relative, prepend the source host and the base tag's path
  #  (11)     if the base href is path-relative
  #  (12)         if the link is host-relative, just prepend the source host
  #  (13)         otherwise it's path-relative, prepend the source host, request's path, and base tag's path
  #  (14) if the base tag is rewritten, we need to use the base tag's path (maybe) and the source host (that's what the base tag was originally)
  #  (15)     if the link is host-relative, just prepend the source host
  #  (16)     otherwise it's path-relative, prepend the source host and base's path
  #
  # these numbers are referenced in the code so You can see where step X is done
  match_not(fetch("./@" + %attr_name), "") {
    %base_tag_value = ""
    $("/html/head/base[@href]") {
      # try to fetch from initial-value attribute (will be set if it was rewrite_links() was called prior)
      attribute("initial-value") {
        %attr_val = value()
        %base_tag_value {
          set(%attr_val)
        }
      }
      # if that didn't work, we haven't rewritten it yet, so use its current value
      match(%base_tag_value, "") {
        attribute("href") {
          %attr_val = value()
          %base_tag_value {
            set(%attr_val)
          }
        }
      }
    }
    attribute(%attr_name) {
      value() {
        %link_host = ""
        url(this()) {
          %temp_val = host()
          %link_host {
            set(%temp_val)
          }
        }
        match(%link_host, "") { # link is unproxiable, not an absolute link (1)
          %rewritten_base_tag_value = %base_tag_value
          %rewritten_base_tag_value {
            rewrite_link()
          }
          # begin (2)
          %slash_path = $path
          %slash_path {
            replace(/[^\/]+$/, "")
            # turn empty string into a single slash because this is the only thing separating the host from a path relative path
            replace(/^$/, "/")
          }
          %base_tag_slash_path = "" # make the variable at this scope
          url(%base_tag_value) {
            %temp_val = path()
            %base_tag_slash_path {
              set(%temp_val)
            }
          }
          %base_tag_slash_path {
            replace(/[^\/]+$/, "")
            # turn empty string into a single slash because this is the only thing separating the host from a path relative path
            replace(/^$/, "/")
          }
          # end (2)
          match(%base_tag_value) {
            with("") { # no base tag (3)
              match(this()) {
                with(/^\//) {
                  prepend(concat("//",$source_host)) # (4)
                }
                else() {
                  prepend(concat("//",$source_host,%slash_path)) # (5)
                }
              }
            }
            with(%rewritten_base_tag_value) { # base tag doesn't get rewritten... (6)
              match(%base_tag_value) {
                with(/\A(?>[a-z]+:|\/\/)/) {
                  # intentionally left blank, base_tag_value has host or scheme and doesn't get rewritten
                  # so the browser should generate the correct absolute path automatically (7)
                }
                with(/^\//) { # base tag is host relative (8)
                  match(this()) {
                    with(/^\//) {
                      prepend(concat("//",$source_host)) # (9)
                    }
                    else() {
                      prepend(concat("//",$source_host,%base_tag_slash_path)) # (10)
                    }
                  }
                }
                else() { # base tag is path relative (11)
                  match(this()) {
                    with(/^\//) {
                      prepend(concat("//",$source_host)) # (12)
                    }
                    else() {
                      prepend(concat("//",$source_host,%slash_path,%base_tag_slash_path)) # (13)
                    }
                  }
                }
              }
            }
            else() { # base tag gets rewritten, so we just want to use the source host + base tag's slash path if needed (14)
              match(this()) {
                with(/^\//) {
                  prepend(concat("//",$source_host)) # (15)
                }
                else() {
                  prepend(concat("//",$source_host,%base_tag_slash_path)) # (16)
                }
              }
            }
          }
        }
      }
    }
  }
}

node:

XMLNode

THE

unproxy_srcs(Text %selector)

FUNCTION

mixer

core-rewriter 2.2.232

category

Modify

{

Overview

Unproxies the src attribute of XMLNodes the parameter selects.

The unproxy_srcs function is a wrapper for the unproxy function. It will use the passed XPath selector and call unproxy on the src attribute of all nodes that match. The net result is that all src attributes it touches will be correctly unproxied, taking into account the nuanced interactions of the base tag, should it exist. # The example below will unproxy the src attribute of every img and script that has a src attribute.

Argument

Type

Name

%selector

Example

$("/html") {
  unproxy_srcs("//img|//script[@src]")
}

View Source

@func XMLNode.unproxy_srcs(Text %selector) {
  $(%selector) {
    unproxy("src")
  }
} {
  // [native function]
}