scratchpad made me happy

March 5th, 2014

I love the Firefox devtools command line. I cut & paste all kinds of crazy code into it. On the other hand, I never did really quite “get” the Scratchpad, though to be honest I also haven’t tried using it much. I’ve been happy just to edit code in an Emacs buffer on the side and cut & paste.

The Problem

But last night, I ran into a problem that Scratchpad turned out to be perfect for. And now I loveses it. My precioussssss….

I am the proud survivor — er, I mean “father” — of two kids, one of whom goes to a school with lots of required “volunteer” time. Since it is required, you have to record your hours via a web-based tool. It’s a fairly primitive interface on some ancient backend ASP monstrosity. It’s tolerable to use to record one entry at a time — you just need to enter a date, a start hour, a start minute, an end hour, an end minute, three options selected from dropdown lists of several dozen items (enough to require scrolling), etc.

Ok, it’s pretty awful even for entering one record.

But entering 80 of the things, most of them differing only by the date, is intolerable. Especially since the d#@n form resets itself completely every time you submit it. And so automation rage kicked in.

Existing Solution

Last year, I did it by capturing the POST request and writing a script to resubmit with different values. It worked, kinda, though I could only get a couple of fields working and it kept timing out my authentication cookie. Or something. I just remember it being a major pain. Even capturing the full request was a little difficult since it’s HTTPS only and I seem to remember some limitation in the Firefox devtools of the time when trying to see the POST body data. (Again, “or something”.)

The Latest Hotness

This year, I was overjoyed to see the option to edit and resubmit a query. I’ve wanted that so many times. And yet… the data was still x-www-form-urlencoded, which means I had to cut & paste from the devtools pane, which is already a challenge due to Linux/xorg/xfce/emacs’s mishandling of cut buffers or clipboards or whatever the heck they are. And then find the field I cared about and update it, and then discover that it overwrote my previous entry because there was some embedded token in one of the other fields that referred to the entry it was creating. Ugh. (Dim memories resurfaced at about this point from when I needed to get around this last year. I still don’t remember the details.)

So then I thought, “hey, I’ll just update the page in place and then click submit! I’ll do it at the HTML level instead of the HTTP level!” So I wrote up some JS code to find and set the various form fields, and clicked submit. Success!

Only it’s still a painful flow. I have to edit the relevant field in emacs (or eventually, I’d probably generate the JS scripts with a shell or Perl or Python script), cut & paste into the little tiny console line (it’s a console prompt, it’s supposed to be small, I have no issue with that.) (Though maybe pasting into the console itself should send it to the prompt? I dunno.), press enter, then click on submit. Not too bad, and definitely well within the “tolerable” zone.

But it’d be easier if I could just define a JS function that finds and fills the fields, and pass in the one value I need to change. Then I can just enter that at the console. Only where can I stash the function? If I put it on the page, I assume it’ll get nuked whenever I submit the page. Hey, I wonder if that Scratchpad thing might help here…

Enter the Scratchpad. Oh yeah.

So I pasted my little script into the Scratchpad. It defines a function to fill out the fields. Final flow: edit one line of JS to change a date, press Ctrl-R to run it. The fields magically update, I click submit.

Obviously, I could’ve done the submit from the script while I was at it, but I like to set things up and fire them off in separate steps. Call it paranoia. I do the same thing with shell scripts — I’ll write a script to echo out a series of commands to perform, run it once to verify that it’s what I want, then run it again piped through bash. I’m just too clumsy to get it right the first time.

But anyway, Scratchpad was the awesome for this task. I’ll be considering it whenever thinking about how to do other things now.

Doers of Good

Thank you robcee and #devtools team. You made my life gooder. More goodish. I am now living goodlier.

My Example

The script I used, if you’re curious:

function enter(date) {
    inputs = document.forms[0].getElementsByTagName("input");
    selects = document.forms[0].getElementsByTagName("select");
    texts = document.forms[0].getElementsByTagName("textarea");
    inputs["VolunteerDate"].value = date;
    inputs["FromHour"].value = 8;
    inputs["FromMin"].value = 45;
    inputs["ToHour"].value = 9;
    inputs["ToMin"].value = 45;
    inputs["nohour"].value = 1;
    selects["MinCombo"].value = 0;
    selects["classcombo"].value = 40;
    selects["activitycombo"].value = 88;
    selects["VolunteerCombo"].value = "Steve Fink";
    texts[0].innerHTML = "Unit study center";

enter("2/27/2014") # I edit this line and bounce on the Ctrl-R key, then click submit

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