Add New Grid Rows via Channel Form

Question

I have a channel where I would like admin to be able to create entries and then anonymous users would be able to add rows to a grid field. I do not want the users to be able to see existing rows(if they exist), just add.

I thought I would be able to get the total rows, and with the Simple Math plugin, make Channel Form ready to add a new row.

<input class="input-block-level" type="text" name="field_id_44[rows][new_row_{exp:simple_math calculate="{shipping_quotes:total_rows} + 1" decimal_places="0"}][col_id_6]" value="">

Which actually works as expected

<input class="input-block-level" type="text" name="field_id_44[rows][new_row_2][col_id_6]" value=""

So [new_row_2] outputs as "2" because in this case there is already an existing row. This works no matter how many rows I add. If the entry has 3 rows in this grid field, it outputs [new_row_4]... as expected.

But this unfortunately doesn't translate when submitting the form. Submitting just replaces the existing row(#1), so I think I am misunderstanding how to add new rows via Channel Form.

So long story short, how do I add rows to a grid field via channel form.

Answer 1

This looks to be a duplicate of this : Adding New Grid Entries With Channel:Form

(you can use the same logic while switching Matrix with Grid, Or Channel form with SafeCracker Form)

Check out that question and my answer, it basically deals with what you're asking.

In short what you need to do is make sure you have the previously set rows in the Channel form as hidden elements. When you sumbit the channel entry form it takes your grid/matrix values in their entirety and saved them as the field value, it does not append them. So as you see, you will need to add the existing values to the form, then add your new values, and submit the whole lot!