Class: PdfRenderer::Base

Inherits:
Object
  • Object
show all
Includes:
ActionMailer::AdvAttrAccessor, Helpers
Defined in:
lib/pdf_renderer/base.rb

Overview

Base class for rendering PDFs. PDFs are rendered in two passes. The first pass evaluates an LaTeX ERB template. In the second pass the evaluated output is piped through pdflatex. The resulting PDF is returned as a string.

Usage

The usage is very similar to ActionMailer. Example:

class BillPdfRenderer < PdfRenderer::Base
  def bill(model)
    body :variable => model
  end
end

Render the PDF using

pdf_as_string = BillPdfRenderer.render_bill(model)

The default template path is underscored_class_name/action_name.pdf.erb and is looked for in all specified view_paths.

Saving PDFs

You can also use PdfRenderer::Base to generate and save PDFs to the file system. Instead of calling render_

Helpers

To use view helpers, declare them in class scope. You can declare them as symbols, strings or constants, camelized or underscored. Omit the “Helper” suffix when using strings or symbols.

The LatexHelper included in the PdfRenderer gem is automatically added to the ActionView instance. This helper contains methods for escaping strings to LaTeX.

Options

Inside of render actions, there are a couple of options you can use:

preprocess

Run pdflatex twice for assigning page numbers etc.

debug

Save the rendered tex source to the file system for debugging.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Helpers

included

Constructor Details

#initialize ⇒ Base

Sets default options

preprocess

false

debug

false



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# File 'lib/pdf_renderer/base.rb', line 61

def initialize
  preprocess false
  debug false
end

Instance Attribute Details

#tex_out ⇒ Object (readonly)

Contains the input for LaTeX



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# File 'lib/pdf_renderer/base.rb', line 52

def tex_out
  @tex_out
end

Class Method Details

.method_missing(method, *params) ⇒ Object

Depending on the method pattern, does one of three things:

  • If the method name starts with render_, the action is called on a new instance of the renderer and the rendered PDF is returned as a string.

  • If the method starts with save_, the action is called, the PDF is generated and saved to the path given in the first method argument.

  • Otherwise, the action is called on a new instance of the renderer and a Pdf object is returned.



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# File 'lib/pdf_renderer/base.rb', line 76

def self.method_missing(method, *params)
  if method.to_s =~ /^render_(.*)$/
    pdf = send($1, *params)
    pdf.render!
  elsif method.to_s =~ /^save_(.*)$/
    file_name = params.shift
    pdf = send($1, *params)
    pdf.save(file_name)
  elsif instance_methods.include?(method.to_s)
    renderer_instance = new
    renderer_instance.template_name = method
    renderer_instance.send(renderer_instance.template_name, *params)
    Pdf.new(renderer_instance)
  else
    super
  end
end

.template_root ⇒ Object

The root for view files.



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# File 'lib/pdf_renderer/base.rb', line 95

def self.template_root
  "#{RAILS_ROOT}/app/views"
end

Instance Method Details

#render(options) ⇒ Object

Delegates the render call to ActionView and runs the resulting LaTeX code through pdflatex.



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# File 'lib/pdf_renderer/base.rb', line 111

def render(options)
  @tex_out = template_instance.render options
  Latex.new(:preprocess => preprocess, :debug => debug).generate_pdf(tex_out)
end

#render! ⇒ Object

Renders the default template.



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# File 'lib/pdf_renderer/base.rb', line 117

def render!
  render :file => template_path
end

#template_dir ⇒ Object

The directory in which templates are stored by default for this renderer.



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# File 'lib/pdf_renderer/base.rb', line 100

def template_dir
  self.class.name.underscore
end

#template_path ⇒ Object

The complete path to the LaTeX ERB template.



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# File 'lib/pdf_renderer/base.rb', line 105

def template_path
  "#{template_dir}/#{template_name}"
end