How do I use a for loop to create multiple dataframes from multiple files r

Question

I have a about 150 tables that I am hoping to make as many flexdashboards for, but don't want to knit each manually. I am using a for loop in a r script to hopefully render those rmd files as .html

setwd("/Volumes/G-DRIVE mobile USB/r/tables 7")
file_list <- list.files()

library(rmarkdown)

for (file in file_list){
  render("template.Rmd",output_file = paste0('report.', file, '.html'))    
}

The "template.Rmd" file is where my flexdashboard is created, but this is where I get stuck. What should I put as the maxtrix name for the dataframe (____$var1)? Or am I missing something else? I've tried a few things, but nothing's really worked. Some produce all the .html files and the dashboard layout is there, but nothing is plotted.

---
title: "Example Dasboard"
output: 
  flexdashboard::flex_dashboard:
    orientation: rows
---

```{r setup, include=FALSE}
library(ggplot2)
library(plotly)
library(plyr)
library(flexdashboard)
library(RCurl)
library(ggthemes)


df<- data.frame(Name = (file),
                   Date = as.Date(file$date, format = "%m/%d/%Y"),
                   var1 = (file$var1),
                   var2 = (file$var2), 
                   var3 = (file$var3),
                   var3a = (file$var3/((file$var4/2.204)^0.66)),
                   var4 = (file$var4),
                   var5 = (file$var5Total),
                   var6 = (file$var6))


```

Objective Measures
=======================================================================

Row
-----------------------------------------------------------------------

### Var3
```{r}
p<-ggplot(df[which(df$Date>"2017-8-1"),],aes(Date,var3))+geom_point()+stat_smooth(color="red", fill="black")+
    theme(axis.title.x = element_blank()) + ylab("")+xlab("")+
    scale_x_date(date_breaks = "months", date_labels = "%b%y")+theme_hc()
ggplotly(p)
```

### var1
 ```{r}
p<-ggplot(df[which(df$Date>"2017-8-1"),],aes(Date,var1))+geom_point()+stat_smooth(color="red", fill="black")+
    theme(axis.title.x = element_blank()) + ylab("")+xlab("")+ 
    scale_x_date(date_breaks = "months", date_labels = "%b%y")+theme_hc()
ggplotly(p)
```

Row
-----------------------------------------------------------------------

### Var4

```{r}
p<-ggplot(df[which(df$Date>"2017-8-1"),],aes(Date,var4))+geom_point()+stat_smooth(color="red", fill="black")+
    theme(axis.title.x = element_blank()) + ylab("")+xlab("")+  scale_x_date(date_breaks = "months", date_labels = "%b%y")+theme_hc()
ggplotly(p)
```

### Var2
```{r}
p<-ggplot(df[which(df$Date>"2017-8-1"),],aes(Date,var2))+geom_point()+stat_smooth(color="red", fill="black")+
    theme(axis.title.x = element_blank()) + ylab("")+xlab("")+  
    scale_x_date(date_breaks = "months", date_labels = "%b%y")+theme_hc()
ggplotly(p)
```


### Var3a
```{r}
p<-ggplot(df[which(df$Date>"2017-8-1"),],aes(Date,var3a))+geom_point()+stat_smooth(color="red", fill="black")+
    theme(axis.title.x = element_blank()) + ylab("")+xlab("")+ 
    scale_x_date(date_breaks = "months", date_labels = "%b%y")+theme_hc()
ggplotly(p)
```

Row
-----------------------------------------------------------------------

### Var5
```{r}
p<-ggplot(df[which(df$Date>"2017-8-1"),], aes(x=Date, y=var5)) +
    geom_bar(stat="identity", fill = "orange") +xlab("") +ylab("") + scale_x_date(date_breaks = "months", date_labels = "%b%y")+theme_hc()
ggplotly(p)
```




Subjective Measures
=======================================================================

Row
-----------------------------------------------------------------------

### Var6
```{r}
p<-ggplot(df[which(df$Date>"2017-8-1"),], aes(x=Date, y=var6)) +
    geom_bar(stat="identity", fill = "green")+ylim(0,10) +xlab("")+ylab("")+ scale_x_date(date_breaks = "months", date_labels = "%b%y")+theme_hc()
ggplotly(p)
```