Note: This is an updated answer. Comments below refer to an old version which messed around with keycodes.
JavaScript
Try it yourself on JSFiddle.
You can filter the input values of a text <input>
with the following setInputFilter
function (supports Copy+Paste, Drag+Drop, keyboard shortcuts, context menu operations, non-typeable keys, the caret position, different keyboard layouts, and all browsers since IE 9):
// Restricts input for the given textbox to the given inputFilter function.
function setInputFilter(textbox, inputFilter) {
["input", "keydown", "keyup", "mousedown", "mouseup", "select", "contextmenu", "drop"].forEach(function(event) {
textbox.addEventListener(event, function() {
if (inputFilter(this.value)) {
this.oldValue = this.value;
this.oldSelectionStart = this.selectionStart;
this.oldSelectionEnd = this.selectionEnd;
} else if (this.hasOwnProperty("oldValue")) {
this.value = this.oldValue;
this.setSelectionRange(this.oldSelectionStart, this.oldSelectionEnd);
} else {
this.value = "";
}
});
});
}
You can now use the setInputFilter
function to install an input filter:
setInputFilter(document.getElementById("myTextBox"), function(value) {
return /^\d*\.?\d*$/.test(value); // Allow digits and '.' only, using a RegExp
});
See the JSFiddle demo for more input filter examples. Also note that you still must do server side validation!
TypeScript
Here is a TypeScript version of this.
function setInputFilter(textbox: Element, inputFilter: (value: string) => boolean): void {
["input", "keydown", "keyup", "mousedown", "mouseup", "select", "contextmenu", "drop"].forEach(function(event) {
textbox.addEventListener(event, function(this: (HTMLInputElement | HTMLTextAreaElement) & {oldValue: string; oldSelectionStart: number | null, oldSelectionEnd: number | null}) {
if (inputFilter(this.value)) {
this.oldValue = this.value;
this.oldSelectionStart = this.selectionStart;
this.oldSelectionEnd = this.selectionEnd;
} else if (Object.prototype.hasOwnProperty.call(this, 'oldValue')) {
this.value = this.oldValue;
if (this.oldSelectionStart !== null &&
this.oldSelectionEnd !== null) {
this.setSelectionRange(this.oldSelectionStart, this.oldSelectionEnd);
}
} else {
this.value = "";
}
});
});
}
jQuery
There is also a jQuery version of this. See this answer.
HTML 5
HTML 5 has a native solution with <input type="number">
(see the specification), but note that browser support varies:
- Most browsers will only validate the input when submitting the form, and not when typing.
- Most mobile browsers don't support the
step
, min
and max
attributes.
- Chrome (version 71.0.3578.98) still allows the user to enter the characters
e
and E
into the field. Also see this question.
- Firefox (version 64.0) and Edge (EdgeHTML version 17.17134) still allow the user to enter any text into the field.
Try it yourself on w3schools.com.
You don't need any plugins to do this.
Just select all lines (CTRL+A) and then from the menu select Edit → Line → Reindent.
This will work if your file is saved with an extension that contains HTML like .html
or .php
.
If you do this often, you may find this key mapping useful:
{ "keys": ["ctrl+shift+r"], "command": "reindent" , "args": { "single_line": false } }
If your file is not saved (e.g. you just pasted in a snippet to a new window), you can manually set the language for indentation by selecting the menu View → Syntax → language of choice
before selecting the reindent option.
Best Answer
What you need is HTML Decode, though unfortunately ASP doesn't include one.
This function, found on ASP Nut, and modified heavily by me, should do what you need. I tested it as vbscript running on my local computer and it seemed to work well, even with Unicode symbols in the 1000+ range.
Note: You'll need script version 5.0 installed on your server to use the RegExp object.