web posts

jQuery AJAX and multipart form handling

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I recently had need to submit a web form with file fields via AJAX. The application uses jQuery and was already submitting forms just fine without file fields using the .serialize() method to pass data to a jQuery.ajax() call. That didn’t seem to handle the file fields, though. Searching the internet, I found a solution using the browser built in FormData object.

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JS: ES Modules and Node bare specifiers via response rewrite

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I’ve been playing with JS lately, including ES modules and building with Rollup, Babel, and Terser, along with other accessories. One thing I’m disappointed with of ES modules in the Nodejs ecosystem is dealing with third party imports. Using the “bare” specifiers that Node expects works fine in that environment and thus tools running in it (possibly needing helpers), but they don’t work at all directly in the browser. This is discussed in this post by Jake Archibold, for instance.

Import maps are one solution in the works, but that requires explicitly mapping every dependency, which could get complicated fast when dependencies have dependencies. It also is only in draft stage and only works in Blink based browsers currently.

I eventually gave in to the idea of having server code rewrite the paths in the js file responses to point to a symlinked node_modules folder, similar to what is mentioned in this post by the Polymer project. I created a PHP test server for one of my projects that does this.

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Fallback webfont and emoji

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Recently I found that browsers will download a fallback webfont (@font-face) to try to find an emoji or other missing character. I was looking at the perf characteristics of my site when I noticed that the browser was downloading a webfont that wasn’t being used at all. After some digging, I found that the browser was going down through the full font stack to try to find an emoji I had added to that page, downloading the webfont on the way.

This is probably not a common setup, but I have a webfont in my font stack down stack from some similar common system fonts, as a fallback just in case. It uses a nice system font unless it can’t find it, in which case it uses the webfont, unless it can’t use that, in which case it uses a less desirable system font or the generic font class.

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Fighting form spam

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Cogneato has dozens of sites with openly submittable forms on them, and they have no doubt all had some level of problems with spam submissions. Bots, and perhaps people, like to share their links or services, try to hack sites, or whatever other nefarious or annoying purposes they may have through forms, which require some sort of server side processing, and will possibly result in human processing as well, such as with sent emails, database data, or comments on a website.

Spammers have gotten more sophisticated over time, and over the last year or two, have really started to hit Cogneato’s sites hard and get past the protections we had in place. We’ve had to add protections on forms that didn’t have them before, and use more techniques to attempt to detect spam. We’ve recently added a set of checks of the submitted form data and the submitter IP address that produces a score of “spaminess” that we can then use to block the submission if the score is above a threshold. That score script is the primary purpose of this post, but I will cover the other techniques we use as well.

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Looking at Apache logs with command line tools

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In my web development career, I have countless times needed to look at Apache logs to figure out or find out about problems with sites, monitor activity, or for various other purposes. I’ve used command line tools to help with this, often looking for strings and counting occurrences. Since I recently needed to create a command string to count unique IP’s connected to a given string in the logs, I thought I’d post about it and a few related useful commands.

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