How to call a JavaScript function multiple times in a loop on page reload with ASP.NET

Question

Hi, I'm using the local database functionality in Chrome and Safari and what I do when I want to save this to a remote database is to create a hidden textfield and then using JSON to stringify each row. In the code behind I then parse each JSON object and insert it into the list. What I want to do now is to delete these rows from the local database. I have a JavaScript function called deletePatient:

function deletePatient(patientID) {
        MaRDB.transaction(
        function (transaction) {
            transaction.executeSql("DELETE FROM Patients WHERE id = " + patientID + ";");
        }
    );
}

I then call this function from the code behind if the insert was successfull

Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "Delete", "<script language='javascript'>$(document).ready(function() {deletePatient(" + id + ");});</script>");

However, it only deletes the patient with the lowest ID (the first JSON object). When I step through the code it goes back to that code for each ID but only deletes one. If I try with an alert it also only shows one ID even though it iterates through the code N number of times. I guess it's some kind of conflict with postback and executing a JavaScript function here but is it possible to solve?

 protected void btnSave_Click(object sender, EventArgs e)
        {
            bool successfullySent = false;

            SharePointConnection();
            int count = Convert.ToInt32(txtRows.Text);

            for (int i = 0; i <= count; i++)
            {   
                string p = String.Format("{0}", Request.Form["hiddenField" + i]).ToString();
                JObject o = JObject.Parse(p);
                id = (int)o["id"];
                string name = (string)o["name"];
                string address = (string)o["address"];
                string city = (string)o["city"];
                string state = (string)o["state"];
                string zip = (string)o["zip"];
                string country = (string)o["country"];
                string phone = (string)o["phone"];

            StringBuilder sb_method = new StringBuilder();
            sb_method.Append("<Method ID='1' Cmd='New'>");

            sb_method.Append("<Field Name='Title'>" + name + "</Field>");
            sb_method.Append("<Field Name='Address'>" + address + "</Field>");
            sb_method.Append("<Field Name='City'>" + city + "</Field>");
            sb_method.Append("<Field Name='State'>" + state + "</Field>");
            sb_method.Append("<Field Name='ZIP'>" + zip + "</Field>");
            sb_method.Append("<Field Name='Country'>" + country + "</Field>");
            sb_method.Append("<Field Name='Phone'>" + phone + "</Field>");

            sb_method.Append("</Method>");

            XmlDocument x_doc = new XmlDocument();
            XmlElement xe_batch = x_doc.CreateElement("Batch");
            xe_batch.SetAttribute("OnError", "Continue");

            xe_batch.InnerXml = sb_method.ToString();

            try
            {
                //updating the list
                XmlNode xn_return = listsObj.UpdateListItems(ConfigurationManager.AppSettings["SaveToSPList"].ToString(), xe_batch);

                if (xn_return.InnerText == "0x00000000")
                {
                    successfullySent = true;
                }
                else
                {
                    successfullySent = false;
                }
            }
            catch
            {
                successfullySent = false;
            }

            if (successfullySent)
            {
                divSuccessfulMessage.Visible = true;
                lblSuccessfulMessage.Text = "Report Successfully Saved";

                Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "Delete", "<script language='javascript'>$(document).ready(function() {deletePatient(" + id + ");});</script>");

            }
            else
            {
                divErrorMessage.Visible = true;
                lblErrorMessage.Text = "Failed to Save, Please Try Again";
            }
        }

}

Thanks in advance.

Answer 1

I'm assuming you're calling the RegisterClientScriptBlock multiple times? In that case, the second parameter of your RegisterClientScriptBlock is the unique key of the script you're trying to inject. Since its always the same, in effect you're basically 'overwriting' each previous script with the latest one.

Try it again, and make sure your key is unique every time you call the RegisterClientScriptBlock (for example, append a counter to it?).

Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "Delete" + counter.ToString(), "<script language='javascript'>$(document).ready(function() {deletePatient(" + id + ");});</script>");