{"id":314,"date":"2011-12-27T21:43:16","date_gmt":"2011-12-28T02:43:16","guid":{"rendered":"http:\/\/littlesvr.ca\/grumble\/?p=314"},"modified":"2012-12-05T00:48:59","modified_gmt":"2012-12-05T05:48:59","slug":"modifying-json-using-a-form","status":"publish","type":"post","link":"http:\/\/littlesvr.ca\/grumble\/2011\/12\/27\/modifying-json-using-a-form\/","title":{"rendered":"Modifying JSON using a form"},"content":{"rendered":"

If you read the slightly older post<\/a> and look at its screenshot and do some thinking – you might like me wonder this: given a bunch of JSON with multiple selections which can be modified in JavaScript using a form.. wait, modified using a form?<\/p>\n

One of the nice things about json is you can just do myjson[x].whatever[whatever].12 = “ABC” and it works. But if all you have is a <select> element and an onClick handler – that’s not so straightforward.<\/p>\n

You can store the string “[x].whatever[whatever].12″ in the value field of the <option> but sadly you cannot just do myjson”[x].whatever[whatever].12” = “DEF”, that’s a syntax error.<\/p>\n

I had to wonder and look for a while, I even found something called JsonPath, which I got really excited about until I realised it’s only for reading (what exactly is the point of it then?). Today I found the solution: eval!<\/p>\n

So continuing the lame example above I would simply do this: eval(‘myjson[‘+x+’].’+whatever+'[‘+whatever’+’].’+12+’ = “‘+”DEF”+'”‘) Roughly speaking, I haven’t tested this line. But you get the point?<\/p>\n

Now that works but luckily because I’m testing with a real pot file I found a bug – all the ‘\\n’ literals in the strings are replaced with newlines by eval, which is not what I want. I found a solution that not only fixes that but I hope will prevent my evals from being hacked: I escape all the backslashes and the single quotes in the string before giving it to eval:<\/p>\n

eval(jsPath + ” = ‘” + text.toString().replace(\/\\\\\/g,’\\\\\\\\’).replace(\/’\/g,”\\\\'”) + “‘;”);<\/p>\n

Yey!<\/p>\n","protected":false},"excerpt":{"rendered":"

If you read the slightly older post and look at its screenshot and do some thinking – you might like me wonder this: given a bunch of JSON with multiple selections which can be modified in JavaScript using a form.. wait, modified using a form? One of the nice things about json is you can … <\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5,4],"tags":[],"class_list":{"0":"entry","1":"post","2":"publish","3":"author-andrew","4":"post-314","6":"format-standard","7":"category-ostd","8":"category-safeforseneca"},"_links":{"self":[{"href":"http:\/\/littlesvr.ca\/grumble\/wp-json\/wp\/v2\/posts\/314","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/littlesvr.ca\/grumble\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/littlesvr.ca\/grumble\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/littlesvr.ca\/grumble\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"http:\/\/littlesvr.ca\/grumble\/wp-json\/wp\/v2\/comments?post=314"}],"version-history":[{"count":3,"href":"http:\/\/littlesvr.ca\/grumble\/wp-json\/wp\/v2\/posts\/314\/revisions"}],"predecessor-version":[{"id":581,"href":"http:\/\/littlesvr.ca\/grumble\/wp-json\/wp\/v2\/posts\/314\/revisions\/581"}],"wp:attachment":[{"href":"http:\/\/littlesvr.ca\/grumble\/wp-json\/wp\/v2\/media?parent=314"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/littlesvr.ca\/grumble\/wp-json\/wp\/v2\/categories?post=314"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/littlesvr.ca\/grumble\/wp-json\/wp\/v2\/tags?post=314"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}