---
title: Render custom descriptions with ERB
slug: render-custom-descriptions-with-erb
published_at: 2021-02-12 18:00:08 +0000
updated_at: 2026-03-04 20:14:30 +0000
summary: 
description: Adding ERB template rendering for description templates using the instance of a Video as the binding. We&#39;re building a tool to sync descriptions to the YouTube API and render the content based on a custom ERB template defined by the user of the application.   Code: https://github.com/cjavdev/video_automation Twitter: https://twitter.com/cjav_dev Feedback: https://forms.gle/Q31hhjJGsMrvY4mL6  It turns out there&#39;s a really excellent tool called TubeBuddy that already exists and does most of what I was planning to build. I&#39;ve started using TubeBuddy in the past few months and really like it. If you use this link to buy a license, I&#39;ll get a small cut for being an affiliate: https://www.tubebuddy.com/cjavdev. #rails #rubyonrails
tags: [Rails, Ruby, Ruby on Rails, YouTube, YouTubeDataAPI, erb, templates, Render custom descriptions with ERB, Render custom ERB template, how to, ruby on rails tutorials, rails tutorials, learn ruby on rails, how to use ruby on rails, learn to code, coding tutorials, web development, ruby on rails tutorial, ruby on rails app]
views: 1157
author: CJ Avilla
url: https://www.cjav.dev/videos/render-custom-descriptions-with-erb
youtube_url: https://www.youtube.com/watch?v=Br6nk3gFjDE
youtube_id: Br6nk3gFjDE
embed_url: https://www.youtube.com/embed/Br6nk3gFjDE
thumbnail_url: https://i.ytimg.com/vi/Br6nk3gFjDE/hqdefault.jpg
type: video
---

# Render custom descriptions with ERB

*Published: February 12, 2021*
*Views: 1157*

## Watch

[Watch on YouTube](https://www.youtube.com/watch?v=Br6nk3gFjDE)

[![Render custom descriptions with ERB](https://i.ytimg.com/vi/Br6nk3gFjDE/hqdefault.jpg)](https://www.youtube.com/watch?v=Br6nk3gFjDE)

## Description

Adding ERB template rendering for description templates using the instance of a Video as the binding. We&#39;re building a tool to sync descriptions to the YouTube API and render the content based on a custom ERB template defined by the user of the application. 

Code: https://github.com/cjavdev/video_automation
Twitter: https://twitter.com/cjav_dev
Feedback: https://forms.gle/Q31hhjJGsMrvY4mL6

It turns out there&#39;s a really excellent tool called TubeBuddy that already exists and does most of what I was planning to build. I&#39;ve started using TubeBuddy in the past few months and really like it. If you use this link to buy a license, I&#39;ll get a small cut for being an affiliate: https://www.tubebuddy.com/cjavdev.
#rails #rubyonrails

## Transcript

all right welcome back we&#39;re going to work on rendering a template so i think the easiest way to do this is just to use erb erb to render the template so let&#39;s go over to our video and let&#39;s add a new method called description and what we want to do is we want to pass in the template the description templates template and we want to use that as our as our template string and then we want to create the binding and i think we can use the binding from from the instance of the video itself so so i think this might work something like let&#39;s let&#39;s actually look it up so erb how to render erb template um okay so erb.new we get the templates okay cool so let&#39;s let&#39;s start with this so the template string is going to be description template dot template safe eval trim mode out var i don&#39;t know what any of those are but we can we can figure that out so like erb template is this thing okay and then we want to say like erb template binding self i think um so let&#39;s just see what this feels like rails c okay and we want to say something like so video video.first v dot description private method binding called for erb so how does that work oh result result and then we pass in do we want to pass in binding or do we want to pass in self let&#39;s let&#39;s pass itself and see what happens okay so video.first.description expected binding okay uh all right so finding sure okay so video.first a description cool so that gave us back test that&#39;s exactly like what the descriptions thing is so let&#39;s see so d is description template dot first d dot template is equal to let&#39;s make it let&#39;s print out like a pound pound pound and then the the name right so title and then we&#39;ll do like new line new line and then say maybe chapter markers and d.save okay and then if we go back to video.first a description oh sweet look at that okay so then we have the description and we have the chapter markers look at that sweet that&#39;s so cool okay so we probably want a way to edit our description templates so they come out like this and if i pee this or puts this oh my gosh look at that it&#39;s so beautiful i love it okay so all right so let&#39;s let&#39;s make a i mean that was like pretty simple right like you you create an erb template and then you pass in the template string and then you render it based on the contents of the video like i think we&#39;re going to want to pass in more stuff but because we have access to presenters and like resources and such we should be able to loop over them and everything based on our template so let&#39;s make a tool that can create the template so rails g controller description templates and we want a an index and a new and edit cool so we&#39;re going to open up description templates new actually let&#39;s go to routes first too and say [Music] resources description templates i&#39;m so tempted to say resources instead of resources every single time when i was when i was deployed there&#39;s this guy giordano that&#39;s his last name who every single day we had to give like a brief and he would he would use like alternate pronunciations of different words for the entire brief and i would die laughing um because it was it was hilarious and it kept it kept the mood light it was it was tough it was tough work we we worked like 13 hours a day so that we had a one hour overlap with our counterparts um or like third 30 minutes in the beginning 30 minutes in the end with our counterparts so it was it was super long days and you just like constantly flip back and forth between different pronunciations or pronunciations or whatever like each time that he encountered the word it was pretty funny all right so for the new uh a form we&#39;re going to say like a description templates and we&#39;re going to have a div that&#39;s going to have a label and it&#39;s going to have the name name and gosh input text the name is going to be description template i should just call this template whatever description template name and the id is going to be name and the value is going to be the description template.name okay i think that&#39;s right and this is going to be label for the actual template um in herb for template text area and the name is going to be description template name and the id is template and the rows here let&#39;s make this a little bit bigger um i don&#39;t know 20. that&#39;s probably a bit excessive but whatever at description template dot name or no dot template okay cool and then we&#39;ll say yeah submit and then we can we can do the same sort of dance we did for presenter in the form here uh description template okay and then same deal with this cool and then we want to pull this whole thing out into a partial and we&#39;ll paste it there and then we&#39;re going to render that form okay so if we go back to our application here and we go to templates we should see nope oh it should be description templates oh gosh that&#39;s winded uh yeah i&#39;m probably going to rename this i don&#39;t know why i went that hard um uh at this templates that each do template um link to edit for the template uh yeah uh edit description template path template hopefully this is giving you some ideas too about like what&#39;s possible um in rails like just with raw html which is pretty powerful right like um okay we&#39;re gonna fetch all the templates refresh the page so we&#39;ve got our test template that&#39;s cool one thing i haven&#39;t been doing is adding description templates is adding links to go create a new one yeah let&#39;s say uh link to add and it&#39;ll be like new description template path so you can see all the paths too if you run um uh rake uh routes or i think maybe rails routes is it i think it changed rails routes this will show you it should show you like the list of all the routes that are possible right and so you&#39;ll see like okay um here there&#39;s actually a bunch of new ones uh for action mailer and action storage and stuff like that but by default right we have a we&#39;ll have like a get route that matches on the path description templates slash id with a optional dot format and the name of the route is description underscore template and you can put like description underscore template underscore path and that will return the path for you or description underscore template and and so when you when you call description underscore template underscore path right this one because it has a required id you have to pass it an object which responds to that id thing so that it can tell you description template slash one or description template slash two so for like for example this description templates path here doesn&#39;t have any required like um dynamic path or anything so you can just call description templates underscore path and that will give you back like slash description templates um there&#39;s also one that you can append underscore url to the end of these names that&#39;ll give you like the fully qualified url so like i think it looks up your domain and port in the production config for action mailer where you can set like the url the actual url we&#39;re not going to do that today but just want to show this this is handy if you&#39;re trying to like look up what the name of the path is let&#39;s do the same thing here add and this will be like new presenter path okay all right so we&#39;ve got add so we&#39;re going to add a new template per assisted for nail class okay so description this thing needs an at description template is just okay i&#39;m just going to change it now template is description template dot find params id um same thing down here and then in our form this just becomes template so change i need to change at at description underscore to just at i think that works maybe could not find a description template without an id huh what oh yeah that&#39;s because it doesn&#39;t exist okay so in new we want to say like new and edit we want to find one all right so there we go we&#39;ve got our name it&#39;s going to be like testing again and in here we want to say like okay this is going to be the title and then we want to say um presenters or maybe we don&#39;t even have this thing at the beginning we&#39;ll just say like title um oh shoot you know what we want we want a summary too but we&#39;ll add that in a bit so for presenters we&#39;re going to say like presenters.each do presenter then we can say presenter.name and dash presenter.twitter handle okay and then we might have like some other stuff like this is common text that we put in all descriptions okay and then if we submit create could not be found um a template is description template template params if at template dot save redirect to templates path else dot now errors is equal to at template.errors.full messages render new and then otherwise let&#39;s see if or like update no def up def update okay okay let&#39;s see template okay shoot uh redirect to i have some snippets um for vim if you want to check them out i have a i usually i keep them pretty up to date they&#39;re um in my github repository um let&#39;s see github.com cjav dev slash uh i think it&#39;s like vim snippets or something like that if you want to take a look redirect to templates path and then we&#39;re going to say otherwise we&#39;re going to do these two things again and instead of new we&#39;ll render update also i realize that i haven&#39;t actually like handled errors but i&#39;m just trying to like do it in a nice general way where i&#39;m always putting the errors into this flash.now thing and then we&#39;ll we&#39;ll handle it some some general way later in the application controller or application layout maybe or something i don&#39;t know private def template params [Music] dot params.requiretemplate.com the name and the template okay and i can&#39;t remember if the form actually uses template or description template yeah let&#39;s change this to template i think i&#39;m going to keep the model name description template and then just keep the stuff that&#39;s local to it name it template so that if later there&#39;s a different template like for the thumbnail or something it&#39;s uh namespaced to that but oh no okay we lost it test uh presenters are presenters dot pluck id let&#39;s see if that works submit null value in template column violates non-null constraint what it&#39;s right here did i not pass it as template template um template oh template template okay let&#39;s see back uh refresh test submit oh my gosh what is up with that oh right because the templates controller doesn&#39;t know about this it needs to be uh description templates path okay so all right let&#39;s add another one let&#39;s make this one serious and we&#39;ll say okay so at the top we&#39;re going to have the title and then we&#39;re going to have the summary but we&#39;re not going to do that for now then we&#39;re going to have presenters and then we&#39;ll have presenter.each do presenter and this will say put out the presenter.name and presenter.twitter handle okay and then if we submit okay so then if we go back to our videos and we edit the video and we pick our new serious template and we update the video now we&#39;ve got that that longish looking description but if we go to our um video show down here what we can do is like let&#39;s put it inside of a pre tag um just so we can see it a little bit better and we&#39;ll just say like at video dot description and that should render the h or should like yeah render the erb template oh cool nice undefined local variable or method presenter for video um so let&#39;s go back to oh gosh how do i hide that thing um slash presenters and or no slash description templates and we want to edit this thing oh gosh we don&#39;t have a form yet uh is it here no okay so then edit uh at template.name okay so we&#39;re editing serious presenters.each okay so then we submit so that oh my gosh i misspelled something again in the update template template params okay so edit serious presenters cool submit cool go back to home go to video oh sweet wait no it doesn&#39;t have any presenters okay so edit and then we want to add tony stark test and stevie update the video and refresh and why are you not rendering oh we didn&#39;t pick sirius as our template update the video holy smokes look at that that is so awesome i love it i love everything about it it&#39;s so beautiful we&#39;ve got a we&#39;ve got a thing that makes things um this is this is super cool i like this a lot uh what we might want to do also is like another thing we could do is in the video show is put this let&#39;s just put it in an input to make it a little easier to um or a text area let&#39;s see so we can copy it easier test video okay so let&#39;s make it like we should make it huge uh rose is like 20 calls it&#39;s like i don&#39;t know 100. nice cool probably a little excessive 60 uh sweet look at that that is so cool okay so now [Music] hmm how come it has this white space that&#39;s leading i don&#39;t know but um this is looking super cool and i think the next step is that we want to well we got to clean this up a little bit so we got to make it so there&#39;s no white space and so that maybe the the twitter handle is like actually like a link to twitter and stuff but this this should all actually be um oh you know what we could do is we could have it be handle or url yeah let&#39;s do that so in the presenter this could be twitter url and this would just be like uh whatever it is like um twitter handle and now from our template right we can call um we can go back to our template home uh let&#39;s let&#39;s let&#39;s do that let&#39;s add some more links here okay so for our templates we&#39;re going to edit our series template and we&#39;re going to say twitter url and then i i bet you it&#39;s because of that right like maybe and then if we go back to our video yeah so now there&#39;s no leading white space and we&#39;ve got our thing that&#39;s printing out wow that&#39;s so cool oh so then if um yeah so then presenter if it doesn&#39;t have a twitter url so we should do this we should only just like if um if twitter if it&#39;s not blank otherwise we should just like not print anything out right so like there we go boom look at that sweet oh my gosh this is so cool sweet all right so resources we&#39;ve got to figure out resources next so i am actually going to call it quits for the day and we&#39;ll come back next time and we can work on banging out links to resources which i think will be pretty cool so thanks for sticking with me we&#39;ll see you next time you

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