support for tikz externalize

make copy of main file as output.tex for tikz externalize

services/clsi/app/coffee/CompileManager.coffee

@@ -8,6 +8,7 @@ logger = require "logger-sharelatex"
 Metrics = require "./Metrics"
 child_process = require "child_process"
 DraftModeManager = require "./DraftModeManager"
+TikzManager = require "./TikzManager"
 fs = require("fs")
 fse = require "fs-extra"
 os = require("os")
@@ -42,6 +43,12 @@ module.exports = CompileManager =
 				else
 					callback()
 
+			createTikzFileIfRequired = (callback) ->
+				if TikzManager.needsOutputFile(request.rootResourcePath, request.resources)
+					TikzManager.injectOutputFile compileDir, request.rootResourcePath, callback
+				else
+					callback()
+
 			# set up environment variables for chktex
 			env = {}
 			# only run chktex on LaTeX files (not knitr .Rtex files or any others)
@@ -54,7 +61,8 @@ module.exports = CompileManager =
 				if request.check is 'validate'
 					env['CHKTEX_VALIDATE'] =  1
 
-			injectDraftModeIfRequired (error) ->
+			# apply a series of file modifications/creations for draft mode and tikz
+			async.series [injectDraftModeIfRequired, createTikzFileIfRequired], (error) ->
 				return callback(error) if error?
 				timer = new Metrics.Timer("run-compile")
 				# find the image tag to log it as a metric, e.g. 2015.1 (convert . to - for graphite)

services/clsi/app/coffee/ResourceWriter.coffee

@@ -50,6 +50,8 @@ module.exports = ResourceWriter =
 						should_delete = false
 					if path == "output.pdf" or path == "output.dvi" or path == "output.log"
 						should_delete = true
+					if path == "output.tex" # created by TikzManager if present in output files
+						should_delete = true
 					if should_delete
 						jobs.push (callback) -> ResourceWriter._deleteFileIfNotDirectory Path.join(basePath, path), callback
 

services/clsi/app/coffee/TikzManager.coffee

@@ -0,0 +1,37 @@
+fs = require "fs"
+Path = require "path"
+logger = require "logger-sharelatex"
+
+# for \tikzexternalize to work the main file needs to match the
+# jobname.  Since we set the -jobname to output, we have to create a
+# copy of the main file as 'output.tex'.
+
+module.exports = TikzManager =
+	needsOutputFile: (rootResourcePath, resources) ->
+		# if there's already an output.tex file, we don't want to touch it
+		for resource in resources
+			if resource.path is "output.tex"
+				return false
+		# if there's no output.tex, see if we are using tikz/pgf in the main file
+		for resource in resources
+			if resource.path is rootResourcePath
+				return TikzManager._includesTikz (resource)
+		# otherwise false
+		return false
+
+	_includesTikz: (resource) ->
+		# check if we are loading tikz or pgf
+		content = resource.content.slice(0,4096)
+		if content.indexOf("\\usepackage{tikz") >= 0
+			return true
+		else if content.indexOf("\\usepackage{pgf") >= 0
+			return true
+		else
+			return false
+
+	injectOutputFile: (compileDir, mainFile, callback = (error) ->) ->
+		fs.readFile Path.join(compileDir, mainFile), "utf8", (error, content) ->
+			return callback(error) if error?
+			logger.log compileDir: compileDir, mainFile: mainFile, "copied file to ouput.tex for tikz"
+			# use wx flag to ensure that output file does not already exist
+			fs.writeFile Path.join(compileDir, "output.tex"), content, {flag:'wx'}, callback

services/clsi/test/unit/coffee/TikzManager.coffee

@@ -0,0 +1,65 @@
+SandboxedModule = require('sandboxed-module')
+sinon = require('sinon')
+require('chai').should()
+modulePath = require('path').join __dirname, '../../../app/js/TikzManager'
+
+describe 'TikzManager', ->
+	beforeEach ->
+		@TikzManager = SandboxedModule.require modulePath, requires:
+			"fs": @fs = {}
+			"logger-sharelatex": @logger = {log: () ->}
+
+	describe "needsOutputFile", ->
+		it "should return true if there is a usepackage{tikz}", ->
+			@TikzManager.needsOutputFile("main.tex", [
+				{ path: 'foo.tex' },
+				{ path: 'main.tex', content:'foo \\usepackage{tikz}' }
+			]).should.equal true
+
+		it "should return true if there is a usepackage{pgf}", ->
+			@TikzManager.needsOutputFile("main.tex", [
+				{ path: 'foo.tex'},
+				{ path: 'main.tex', content:'foo \\usepackage{pgf}' }
+			]).should.equal true
+
+		it "should return false if there is no usepackage{tikz} or {pgf}", ->
+			@TikzManager.needsOutputFile("main.tex", [
+				{ path: 'foo.tex' },
+				{ path: 'main.tex', content:'foo \\usepackage{bar}' }
+			]).should.equal false
+
+		it "should return false if there is already an output.tex file", ->
+			@TikzManager.needsOutputFile("main.tex", [
+				{ path: 'foo.tex' },
+				{ path: 'main.tex' },
+				{ path: 'output.tex' }
+			]).should.equal false
+
+	describe "injectOutputFile", ->
+		beforeEach ->
+			@rootDir = "/mock"
+			@filename = "filename.tex"
+			@callback = sinon.stub()
+			@content = '''
+				\\documentclass{article}
+				\\usepackage{tikz}
+				\\begin{document}
+				Hello world
+				\\end{document}
+			'''
+			@fs.readFile = sinon.stub().callsArgWith(2, null, @content)
+			@fs.writeFile = sinon.stub().callsArg(3)
+			@TikzManager.injectOutputFile @rootDir, @filename, @callback
+
+		it "should read the file", ->
+			@fs.readFile
+				.calledWith("#{@rootDir}/#{@filename}", "utf8")
+				.should.equal true
+
+		it "should write out the same file as output.tex", ->
+			@fs.writeFile
+				.calledWith("#{@rootDir}/output.tex", @content, {flag: 'wx'})
+				.should.equal true
+
+		it "should call the callback", ->
+			@callback.called.should.equal true