Question

I have the following HTML in a string variable myHtml.The myHTML variable is filled with HTML from some function which return the HTML as follows

string myHtml="<table> <tr id='12345'><td>Hello1</td></tr> <tr id='12346'><td>Hello2</td></tr> </table>";

In this example, there are two rows in my returned data, and I need to add another row between the above rows with id=1234678. So then myHtml might look like

myHtml="<table> <tr id='12345'><td>Hello1</td></tr> <tr id='1234678'><td>Hello New</td></tr>  <tr id='12346'><td>Hello2</td></tr> </table>";

I want to do it by appending the HTML with the help of string operations such as indexOf, etc, but I can not figure out how to do this.

Answer 1

Are there always only 2 rows? If so, this will work:

string newRow = " <tr id='1234678'><td>Hello New</td></tr> ";
int i = myHtml.IndexOf("</tr>") + 5;            
string newHtml = myHtml.Insert(i, newRow);

If there could by any number of rows, we’ll need to write a method to find the specific index to insert at.

e.g:

    int IndexOfNth(string source, string token, int nTh)
    {
        int index = source.IndexOf(token);

        if (index != -1)
        {
            int i = 1;
            while (i++ < nTh)
                index = source.IndexOf(token, index + 1);
        }

        return index;
    }

Then you would use:

int i = IndexOfNth(myHtml, "</tr>", 1) + 5; // find first "</tr>" and insert after

// Or you could use
int i = IndexOfNth(myHtml, "<tr ", 2); // find second "<tr " and insert before