Showing posts with label javascript. Show all posts
Showing posts with label javascript. Show all posts

Sunday 25 August 2013

Using regex patterns for verifying input

We have recently been using HTML 5 and JavaScript to do form verification, as Fahad blogged about here

I have just added pattern matching to this for email and telephone number verification. Thanks to +Exson Qu  for the regex ju-ju. 

HTML5 allows form elements of type "tel" and "email". We want to add in a regular expression to each of these types to verify the element as it is typed. The regular expressions we have used are "[0-9 +s()]*" for the telephone numbers, and "^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,4})$" for email addresses. Neither of these are 100% as it is not possible to deal with every method in the world of writing telephone numbers, and every method of constructing emails addresses, however these will do a good job on most.

It is feasible to add html in the form:

<input type="tel" name="Telephone" pattern="[0-9 +s()]*" value="" />

However this would need to be done wherever there is a telephone or fax number to be entered into KwaMoja. Then if we decide to improve the regex we would need to go through all these entries again. This can get messy.

It would be better to do this via JavaScript. We have a function called initial() that gets called when the page has been loaded. This function iterates through all the form elements in the page that has just been loaded and appends the regex pattern any with a type "tel" or a type "email". Here is the function:

function initial() {
    var n = document.getElementsByTagName("input");
    for (i = 0; i < n.length; i++) {
        if (n[i].type == "tel") n[i].pattern = "[0-9 +s()]*";
        if (n[i].type == "email") n[i].pattern = "^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,4})$";
    }
}


We also use this function to assign other properties to form elements.

Monday 5 August 2013

How to sort HTML tables in JavaScript

A short while ago I blogged that KwaMoja now has the facility to sort HTML tables in JavaScript. I have had numerous requests to explain more about how this is done, so here is a brief tutorial on achieving this.

The table has to be constructed in a specific way. The area of the table to be sorted has to contain one row of <th> cells followed by any number of <td> rows.

So the following HTML would be suitable:

<tr>
        <th>Header1</th>
        <th>Header2</th>
</tr>
<tr>
        <td>Data11</td>
        <td>Data12</td>
</tr>
<tr>
        <td>Data21</td>
        <td>Data22</td>
</tr>

which will look like this:


Header1 Header2
Data11 Data12
Data21 Data22

This area to be sorted must be completely contained within a pair of tags, for instance between a <table> and a </table>. If you require other things in the table, then I generally use a <tbody> and a </tbody> to surround the area to be sorted.

The JavaScript function starts with the following:



1 function SortSelect(selElem) {
2    table=selElem.parentNode.parentNode;
3    headerRow = table.rows[0];


The function is called by clicking on the <th></th> element of the column that we wish to sort by. Thus the parameter "selElem" will be that cell. The parent of that cell will be the row (<tr>) containing the header, and the parent of the row will be the element that contains the whole of the sortable table.

Thus line 2 will give us the entire table that we wish to sort. Line 3 assigns the first row of that table to the variable "headerRow"

4    columnText=selElem.innerHTML;
5    for (var j = 0, col; col = headerRow.cells[j]; j++) {
6        if (
headerRow.cells[j].innerHTML==columnText) {
7            columnNumber=j;

8    }

This section finds the column number that is to be sorted on. Line 4 finds the column header, and then lines 5 to 8 loop through the columns until the correct one is found.

09    var tmpArray = new Array();
10    for (var i = 1, row; row = table.rows[i]; i++) {
11        var rowArray = new Array();
12        for (var j = 0, col; col = row.cells[j]; j++) {
13            if (row.cells[j].tagName == 'TD' ) {
14                rowArray[j]=row.cells[j].innerHTML;
15            }
16        }
17        tmpArray[i]=rowArray;
18    }

 
This section gets the information from each cell, and feeds it into a JavaScript array object before sorting it. Line 9 creates the array object then we cycle through each row (starting at the second line, as the first contains the headings), creating an array object for each row, and finally line 17 adds that row array to the main array.

19    tmpArray.sort(
20        function(a,b) {
21                if (columnClass=="number") {
22                    return parseFloat(a[columnNumber])-parseFloat(b[columnNumber]);
23                } else if (columnClass=="date") {
24                    da=new Date(a[columnNumber]);
25                    db=new Date(b[columnNumber]);
26                    return da>db;
27                } else {
28                    return a[columnNumber].localeCompare(b[columnNumber])

29                }
30        }
31    );
 

This section performs a standard JavaScript 3d array sorting routine. It will sort by number, alphabetic, and date. Other sorting routines can be included as needed.

Finally we need to feed the sorted array back into the html table as here

32    for (var i = 0, row; row = table.rows[i+1]; i++) {
33        var rowArray = new Array();
34        rowArray=tmpArray[i];
35        for (var j = 0, col; col = row.cells[j]; j++) {
36            if (row.cells[j].tagName == 'TD' ) {
37                row.cells[j].innerHTML=rowArray[j];
38            }
39        }
40    }
 

and we have fully sorted the HTML table in 40 lines of JavaScript. I have added in some nice formatting, and cursors in, and get the following full function:

function SortSelect(selElem) {
    var tmpArray = new Array();
    th=document.getElementById("Theme").value;
    columnText=selElem.innerHTML;
    table=selElem.parentNode.parentNode;
    row = table.rows[0];
    for (var j = 0, col; col = row.cells[j]; j++) {
        if (row.cells[j].innerHTML==columnText) {
            columnNumber=j;
            s=getComputedStyle(row.cells[j], null);
            if (s.cursor=="s-resize") {
                row.cells[j].style.cursor="n-resize";
                row.cells[j].style.backgroundImage="url('css/"+th+"/images/descending.png')";
                row.cells[j].style.backgroundPosition="right center";
                row.cells[j].style.backgroundRepeat="no-repeat";
                row.cells[j].style.backgroundSize="12px";
                direction="a";
            } else {
                row.cells[j].style.cursor="s-resize";
                row.cells[j].style.backgroundImage="url('css/"+th+"/images/ascending.png')";
                row.cells[j].style.backgroundPosition="right center";
                row.cells[j].style.backgroundRepeat="no-repeat";
                row.cells[j].style.backgroundSize="12px";
                direction="d";
            }
        }
    }
    for (var i = 1, row; row = table.rows[i]; i++) {
        var rowArray = new Array();
        for (var j = 0, col; col = row.cells[j]; j++) {
            if (row.cells[j].tagName == 'TD' ) {
                rowArray[j]=row.cells[j].innerHTML;
                columnClass=row.cells[columnNumber].className;
            }
        }
        tmpArray[i]=rowArray;
    }
    tmpArray.sort(
        function(a,b) {
            if (direction=="a") {
                if (columnClass=="number") {
                    return parseFloat(a[columnNumber])-parseFloat(b[columnNumber]);
                } else if (columnClass=="date") {
                    da=new Date(a[columnNumber]);
                    db=new Date(b[columnNumber]);
                    return da>db;
                } else {
                    return a[columnNumber].localeCompare(b[columnNumber])
                }
            } else {
                if (columnClass=="number") {
                    return parseFloat(b[columnNumber])-parseFloat(a[columnNumber]);
                } else if (columnClass=="date") {
                    da=new Date(a[columnNumber]);
                    db=new Date(b[columnNumber]);
                    return da<=db;
                } else {
                    return b[columnNumber].localeCompare(a[columnNumber])
                }
            }
        }
    );
    for (var i = 0, row; row = table.rows[i+1]; i++) {
        var rowArray = new Array();
        rowArray=tmpArray[i];
        for (var j = 0, col; col = row.cells[j]; j++) {
            if (row.cells[j].tagName == 'TD' ) {
                row.cells[j].innerHTML=rowArray[j];
            }
        }
    }
    return;
}


This is called by including this inline onclick handler

 onclick="SortSelect(this)"

I hope this explanation is useful to some people.

Saturday 27 July 2013

When censorsip goes mad

This page is written in response to the lies that +Phil Daintree has written about me, and spread on the internet. Despite years of searching he has been unable to find anything I have written that is untrue, and he has had to resort to vague generalities, faked emails, and badly fabricated screenshots (you can see the joins if you zoom in using any bit mapped image editor). +Phil Daintree is welcome to make any comments to these pages, as he has done in the past. If I agree with what he says I will amend my writings, if I do not agree I have allowed his comments to stand next to mine so that people can make their own judgements. I have every confidence in the intelligence of readers to make a sensible judgement based on the facts. +Phil Daintree will not allow me the right of reply to any of the lies he has told about me. It seems to me significant that he realises that if people see both sides of the argument they will see through his lies.

In a recent discussion on the webERP mailing list +Phil Daintree was writing about the new confirm boxes I did for +KwaMoja . This is the email he wrote:
Tim has also made some improvements to the confirm boxes but probably
unnecessary really, especially since it adds significantly to the size
of the file. 
 I then wrote back:
It only adds 996 bytes to the file, and this could be shortened further with the use of smaller variable names. To my mind they give a more consistent and professional feel across all browsers.
Phil refused to allow this email on the mailing list (for proof of this see previous blog entries), but I posted it to the nabble forums anyway as I thought it might be interesting to people. I then went away and played with this JavaScript a bit more, and managed to reduce the size of this function a bit more, so I posted the following:
Just for interest I reduced this to 921 bytes (0.899Kb) by using shorter variable names.
I tried this to the mailing list, but as usual it was rejected, so I posted it to the nabble forums. To my surprise it got deleted from there. I re-posted it and it got deleted from there again. It has now been deleted seven times by +Phil Daintree or one of his cohorts.

Now can anybody work out why a short post about reducing the size of a JavaScript function to 922 bytes should be considered so offensive that the readers of the nabble forums and the mailing lists need to be protected from reading it?
The only thing that I can imagine is that a recurring theme in his hate pages about me, is how much better a programmer he is than me, and maybe he thinks this email doesn't help that claim. I can't think of another reason.

Philippians 4:8

Amendment 3/1/2014:  I have since been informed  by +Exson Qu and +Phil Daintree that the reasons for deleting the above postings was that commenting on the length of a JavaScript function constituted a personal attack on +Phil Daintree. I have asked for clarification from either +Exson Qu or +Phil Daintree as to why this was, but have received no reply. My best guess is that +Phil Daintree had already said that including the function "adds significantly to the size of the file", and so my pointing out that it was actually quite small was contradicting him and so constituted a personal attack. Personally I think it constitutes valid technical discussion but I include it here as I have always said I am happy to put both sides of the discussion forward and allow readers to make their own minds up.











 

Friday 19 July 2013

When egos get in the way of managing the project

This page is written in response to the lies that +Phil Daintree  has written about me, and spread on the internet. Despite years of searching he has been unable to find anything I have written that is untrue, and he has had to resort to vague generalities, faked emails, and badly fabricated screenshots (you can see the joins if you zoom in using any bit mapped image editor). +Phil Daintree  is welcome to make any comments to these pages, as he has done in the past. If I agree with what he says I will amend my writings, if I do not agree I have allowed his comments to stand next to mine so that people can make their own judgements. I have every confidence in the intelligence of readers to make a sensible judgement based on the facts. +Phil Daintree will not allow me the right of reply to any of the lies he has told about me. It seems to me significant that he realises that if people see both sides of the argument they will see through his lies.

This post to the webERP mailing list shows the sad state affairs that Phil has allowed the management of the webERP project to sink to.

He is trying to copy my code because he wont allow me to directly commit myself, all because I I inserted a link to this blog in my signature on the forum. The fact that he wants my code in webERP is great, and fully within the spirit in which I contribute it to the GPL.

However his ego wont allow him to ask me for help as he doesn't understand how the code works. I would be more than happy to help if he asks.

The GPL states that he should leave the copyright intact, however he claims the ownership of the copyright to the code that he is copying.

In fact he goes further and doesn't even acknowledge in his commit message, or the change log that the code was written by me.

This is the problem when somebody's ego is bigger than the project.It highlights everything that's wrong with the dishonest way that the webERP project is being run.

Monday 8 July 2013

Sorting html tables

I have just committed the code to sort HTML tables. So far this applies to only certain scripts, but to add it to any is easy, and should be done in all by tomorrow.

Here is the result of searching for stock items in SelectProduct.php


Now by clicking at the top of the Description column the table is automatically sorted and shows
and the items are sorted by item description. Clicking on that column again shows:

and the order of the items is reversed. This also holds true for the code column. I have also done the SelectCustomer.php script and the SelectSupplier.php script.

All this is done with one simple JavaScript function and minimal changes to the scripts.

This and the changes committed by Fahad earlier today means a huge leap forward for usability in KwaMoja. Hope you enjoy this new code.