Template auto layout cell for automatically UITableViewCell height calculating.

If you have a self-satisfied cell, then all you have to do is:

#import "UITableView+FDTemplateLayoutCell.h"

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return [tableView fd_heightForCellWithIdentifier:@"reuse identifer" configuration:^(id cell) {
        // Configure this cell with data, same as what you've done in "-tableView:cellForRowAtIndexPath:"
        // Like:
        //    cell.entity = self.feedEntities[indexPath.row];
    }];
}

Since iOS8, -tableView:heightForRowAtIndexPath: will be called more times than we expect, we can feel these extra calculations when scrolling. So we provide another API with cache by index path:

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
    return [tableView fd_heightForCellWithIdentifier:@"identifer" cacheByIndexPath:indexPath configuration:^(id cell) {
        // configurations
    }];
}

Or, if your entity has an unique identifier, use cache by key API:

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
	Entity *entity = self.entities[indexPath.row];
    return [tableView fd_heightForCellWithIdentifier:@"identifer" cacheByKey:entity.uid configuration:^(id cell) {
        // configurations
    }];
}

FDTemplateLayoutCell offers 2 modes for asking cell's height.

1. Auto layout mode using "-systemLayoutSizeFittingSize:"
2. Frame layout mode using "-sizeThatFits:"

Generally, no need to care about modes, it will automatically choose a proper mode by whether you have set auto layout constrants on cell's content view. If you want to enforce frame layout mode, enable this property in your cell's configuration block:

cell.fd_enforceFrameLayout = YES;

And if you're using frame layout mode, you must override -sizeThatFits: in your customized cell and return content view's height (separator excluded)

- (CGSize)sizeThatFits:(CGSize)size {
    return CGSizeMake(size.width, A+B+C+D+E+....);
}

Debug log helps to debug or inspect what is this "FDTemplateLayoutCell" extention doing, turning on to print logs when "calculating", "precaching" or "hitting cache".Default to "NO", log by "NSLog".

self.tableView.fd_debugLogEnabled = YES;

It will print like this:

** FDTemplateLayoutCell ** layout cell created - FDFeedCell
** FDTemplateLayoutCell ** calculate - [0:0] 233.5
** FDTemplateLayoutCell ** calculate - [0:1] 155.5
** FDTemplateLayoutCell ** calculate - [0:2] 258
** FDTemplateLayoutCell ** calculate - [0:3] 284
** FDTemplateLayoutCell ** precached - [0:3] 284
** FDTemplateLayoutCell ** calculate - [0:4] 278.5
** FDTemplateLayoutCell ** precached - [0:4] 278.5
** FDTemplateLayoutCell ** hit cache - [0:3] 284
** FDTemplateLayoutCell ** hit cache - [0:4] 278.5
** FDTemplateLayoutCell ** hit cache - [0:5] 156
** FDTemplateLayoutCell ** hit cache - [0:6] 165

a fully self-satisfied cell is constrainted by auto layout and each edge("top", "left", "bottom", "right") has at least one layout constraint against it. It's the same concept introduced as "self-sizing cell" in iOS8 using auto layout.

A bad one :( - missing right and bottom

A good one :)

A template layout cell is created by -dequeueReusableCellWithIdentifier: method, it means that you MUST have registered this cell reuse identifier by one of:

• A prototype cell of UITableView in storyboard.
• Use -registerNib:forCellReuseIdentifier:
• Use -registerClass:forCellReuseIdentifier:

可以看这篇中文博客： http://blog.sunnyxx.com/2015/05/17/cell-height-calculation/

Latest version: 1.6

pod search UITableView+FDTemplateLayoutCell 

If you cannot search out the latest version, try:

pod setup

We recommend to use the latest release in cocoapods.

• 1.6 fix bug in iOS 10

• 1.4
  Refactor, add "cacheByKey" mode, bug fixed

• 1.3
  Frame layout mode, handle cell's accessory view/type

• 1.2
  Precache and auto cache invalidation

• 1.1
  Height cache

• 1.0
  Basic automatically height calculation

MIT