CODEWITHSUNDEEP
javascript
Lewis
Lewis

Reputation: 2178

Form element Iteration, in Javascript

I've been working on a code snippet for a template module that I have been creating and I've hit a wall so to speak. I'm trying to loop through all textareas on my page, and apply formatting with some very basic validation.

Javascript is not my strongest suit but I can understand it to a point, my question is how do I collect the ID's and then use them to apply the formatting.

For example,

for each (textarea) 
{
    collect character restriction from html
    display character restriction in a formatted manner
}

I have included my JSFiddle which I have been using to build this snippet.

Upvotes: 0

Views: 67

Answers (2)

user5066707
user5066707

Reputation:

I've based on @FodorZoltán's class. My class does now:

  • append the counter below the textarea;
  • position the counter in the below part of the textarea;

Yeah, I'm lazy and the code has grown up. I added some events and renamed the class name to "TextAreaRanger". It's working here:

var TextAreaRanger = function(input) {

    this.MAX = parseInt(input.getAttribute('maxlength'));
    this.INPUT = input;

    // add input events
    input["oncut"] =
    input["onpaste"] =
    input["onkeydown"] =
    input["onkeyup"] = this.update.bind(this);

    // create wrapper element
    this.wrapper = document.createElement('div');
    this.wrapper.innerHTML = 'Chars left: '+ (this.MAX - input.value.length);

    /* input parent element */
    var ipar = input.parentNode;

    // find input's i
    for (var i = 0, el; el = ipar.children[i]; i ++) {
        if(el === input) break;
    }

    // append wrapper below the input
    if (ipar.children[++i]) {
        ipar.insertBefore(this.wrapper, ipar.children[i]);
    } else ipar.appendChild(this.wrapper);

    /* stylize wrapper */
    this.wrapper.style.position = "relative";
    this.wrapper.style.color = '#f00';
    this.wrapper.style.fontSize = '11px';
    this.wrapper.style.left = (input.offsetLeft + (input.offsetWidth - 100)) + "px";
    this.wrapper.style.top = (-parseInt(this.wrapper.style.fontSize) * 2) + "px";
};

// Update the counter
TextAreaRanger.prototype["update"] = function() {
    this.wrapper.innerHTML = 'Chars left: ' + (this.MAX - this.INPUT.value.length);
};

Upvotes: 1

Fodor Zoltán
Fodor Zoltán

Reputation: 51

I would suggest creating a prototype class for this, that can be extended to do other things aswell:

var CharWatcher = function(input){
  this.max = input.getAttribute('max-length');
  this.input = input;

  input.onKeyDown = this.update.bind(this);

  this.wrapper = document.createElement('div');
  this.wrapper.innerHTML = 'Chars left: '+ (max - input.value.length);
  /* style wrapper element */
  /* append around input */
};

CharWatcher.prototype = {
  update: function(){
     this.wrapper.innerHTML = 'Chars left: ' + (this.max - this.input.value.length);
  }
};

/* Somewhere else */

var textareas = document.getElementsByTagName('textarea');
for(var i = 0, l = textareas.length; i < l; i++)
    new CharWatcher(textareas[i]);

Upvotes: 2

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