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ilovecode
8,071 PointsHow to solve JS errors appearing on different pages due to one JS file
I hope I can explain this in a way that is understandable. I have googled everywhere and I am really lost.
I have a web application on my localhost, with 3 php web pages. The 3 pages use a header and footer includes in each of these pages. Let's call the pages home.php, about.php and contact.php.
I include all my .js files in the footer.php file. But now I have one .js file (custom.js) that I inserted in the footer.php includes file.
Now I am getting errors on the home.php, etc pages if there is js code with DOM selectors not on that page. E.g document.querySelector('.home-body') gives error on about.php and contact.php. Does this mean I have to have a separate js file for each page and insert them inside those files?
I hope this is clear.
Thanks
1 Answer
Michael Cook
Full Stack JavaScript Techdegree Graduate 28,975 PointsYou will get an undefined message if you include a JavaScript file in a PHP file that does not contain the relevant HTML. If you were to use a templating language with a PHP framework like Slim or Laravel then you could solve this problem by dynamically adding in the correct script. Since it sounds like you're using plain PHP and not using an MVC framework, you will just have to hard code in the correct script for each page.
ilovecode
8,071 PointsDoes it also mean that I must then have a different .js file for each page? Currently I am just learning .js without using a framework because I plan to add backend functionality only later on as I learn. I want to learn all the raw concepts first before doing frameworks
Michael Cook
Full Stack JavaScript Techdegree Graduate 28,975 PointsCurrently I would say yes. If you write one single js file for all your pages, then errors will spring up.
I would encourage learning one language at a time. If you're trying to build a website with PHP and JavaScript at the same time you might be biting off more than you can chew. I would recommend working through the Introducing JavaScript track and a first starting point, and then take a PHP track.
ilovecode
8,071 PointsThanks, I have learnt some PHP already, so I am doing the Full Stack Javascript Track now.
Michael Cook
Full Stack JavaScript Techdegree Graduate 28,975 PointsMichael Cook
Full Stack JavaScript Techdegree Graduate 28,975 PointsI would add that this is a very inefficient way of creating a web application. I've worked with plain PHP, but this is really not a good solution for any site or app unless it's just a single page with a simple back-end. If you like working with PHP I would encourage you to invest the overhead to learn the Slim framework. From there once you understand MVC fundamentals you could learn Laravel easier.